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Atay G, Holyavkin C, Can H, Arslan M, Topaloğlu A, Trotta M, Çakar ZP. Evolutionary engineering and molecular characterization of cobalt-resistant Rhodobacter sphaeroides. Front Microbiol 2024; 15:1412294. [PMID: 38993486 PMCID: PMC11236759 DOI: 10.3389/fmicb.2024.1412294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Accepted: 06/12/2024] [Indexed: 07/13/2024] Open
Abstract
With its versatile metabolism including aerobic and anaerobic respiration, photosynthesis, photo-fermentation and nitrogen fixation, Rhodobacter sphaeroides can adapt to diverse environmental and nutritional conditions, including the presence of various stressors such as heavy metals. Thus, it is an important microorganism to study the molecular mechanisms of bacterial stress response and resistance, and to be used as a microbial cell factory for biotechnological applications or bioremediation. In this study, a highly cobalt-resistant and genetically stable R. sphaeroides strain was obtained by evolutionary engineering, also known as adaptive laboratory evolution (ALE), a powerful strategy to improve and characterize genetically complex, desired microbial phenotypes, such as stress resistance. For this purpose, successive batch selection was performed in the presence of gradually increased cobalt stress levels between 0.1-15 mM CoCl2 for 64 passages and without any mutagenesis of the initial population prior to selection. The mutant individuals were randomly chosen from the last population and analyzed in detail. Among these, a highly cobalt-resistant and genetically stable evolved strain called G7 showed significant cross-resistance against various stressors such as iron, magnesium, nickel, aluminum, and NaCl. Growth profiles and flame atomic absorption spectrometry analysis results revealed that in the presence of 4 mM CoCl2 that significantly inhibited growth of the reference strain, the growth of the evolved strain was unaffected, and higher levels of cobalt ions were associated with G7 cells than the reference strain. This may imply that cobalt ions accumulated in or on G7 cells, indicating the potential of G7 for cobalt bioremediation. Whole genome sequencing of the evolved strain identified 23 single nucleotide polymorphisms in various genes that are associated with transcriptional regulators, NifB family-FeMo cofactor biosynthesis, putative virulence factors, TRAP-T family transporter, sodium/proton antiporter, and also in genes with unknown functions, which may have a potential role in the cobalt resistance of R. sphaeroides.
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Affiliation(s)
- Güneş Atay
- Department of Molecular Biology and Genetics, Faculty of Science and Letters, Istanbul Technical University, İstanbul, Türkiye
- Dr. Orhan Öcalgiray Molecular Biology, Biotechnology and Genetics Research Center (İTÜ-MOBGAM), Istanbul Technical University, İstanbul, Türkiye
| | - Can Holyavkin
- Department of Molecular Biology and Genetics, Faculty of Science and Letters, Istanbul Technical University, İstanbul, Türkiye
- Dr. Orhan Öcalgiray Molecular Biology, Biotechnology and Genetics Research Center (İTÜ-MOBGAM), Istanbul Technical University, İstanbul, Türkiye
| | - Hanay Can
- Department of Molecular Biology and Genetics, Faculty of Science and Letters, Istanbul Technical University, İstanbul, Türkiye
- Dr. Orhan Öcalgiray Molecular Biology, Biotechnology and Genetics Research Center (İTÜ-MOBGAM), Istanbul Technical University, İstanbul, Türkiye
| | - Mevlüt Arslan
- Department of Molecular Biology and Genetics, Faculty of Science and Letters, Istanbul Technical University, İstanbul, Türkiye
- Dr. Orhan Öcalgiray Molecular Biology, Biotechnology and Genetics Research Center (İTÜ-MOBGAM), Istanbul Technical University, İstanbul, Türkiye
| | - Alican Topaloğlu
- Department of Molecular Biology and Genetics, Faculty of Science and Letters, Istanbul Technical University, İstanbul, Türkiye
- Dr. Orhan Öcalgiray Molecular Biology, Biotechnology and Genetics Research Center (İTÜ-MOBGAM), Istanbul Technical University, İstanbul, Türkiye
| | - Massimo Trotta
- IPCF-CNR Istituto per I processi Chimico-Fisici, Consiglio Nazionale delle Ricerche, Bari, Italy
| | - Zeynep Petek Çakar
- Department of Molecular Biology and Genetics, Faculty of Science and Letters, Istanbul Technical University, İstanbul, Türkiye
- Dr. Orhan Öcalgiray Molecular Biology, Biotechnology and Genetics Research Center (İTÜ-MOBGAM), Istanbul Technical University, İstanbul, Türkiye
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Xiao Y, Zheng Y, Zhou Y, Yu C, Ye TE. Metabolic flux analysis of coenzyme Q 10 synthesized by Rhodobacter sphaeroides under the influence of different pH regulators. Microb Cell Fact 2023; 22:206. [PMID: 37817171 PMCID: PMC10563333 DOI: 10.1186/s12934-023-02205-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 09/19/2023] [Indexed: 10/12/2023] Open
Abstract
Coenzyme Q10 (CoQ10) is crucial for human beings, especially in the fields of biology and medicine. The aim of this experiment was to investigate the conditions for increasing CoQ10 production. At present, microbial fermentation is the main production method of CoQ10, and the production process of microbial CoQ10 metabolism control fermentation is very critical. Metabolic flux is one of the most important determinants of cell physiology in metabolic engineering. Metabolic flux analysis (MFA) is used to estimate the intracellular flux in metabolic networks. In this experiment, Rhodobacter sphaeroides was used as the research object to analyze the effects of aqueous ammonia (NH3·H2O) and calcium carbonate (CaCO3) on the metabolic flux of CoQ10. When CaCO3 was used to adjust the pH, the yield of CoQ10 was 274.43 mg·L-1 (8.71 mg·g-1 DCW), which was higher than that of NH3·H2O adjustment. The results indicated that when CaCO3 was used to adjust pH, more glucose-6-phosphate (G6P) entered the pentose phosphate (HMP) pathway and produced more NADPH, which enhanced the synthesis of CoQ10. At the chorismic acid node, more metabolic fluxes were involved in the synthesis of p-hydroxybenzoic acid (pHBA; the synthetic precursor of CoQ10), enhancing the anabolic flow of CoQ10. In addition, Ca2+ produced by the reaction of CaCO3 with organic acids promotes the synthesis of CoQ10. In summary, the use of CaCO3 adjustment is more favorable for the synthesis of CoQ10 by R. sphaeroides than NH3·H2O adjustment. The migration of metabolic flux caused by the perturbation of culture conditions was analyzed to compare the changes in the distribution of intracellular metabolic fluxes for the synthesis of CoQ10. Thus, the main nodes of the metabolic network were identified as G6P and chorismic acid. This provides a theoretical basis for the modification of genes related to the CoQ10 synthesis pathway.
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Affiliation(s)
- Yujun Xiao
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Yi Zheng
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China.
| | - Yong Zhou
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Chaofan Yu
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Ting-E Ye
- National Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou, China
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Wang T, Yin Y, Zhang J, Guan H, Xu J, Liu X. Extracellular vesicles as a strategy for cadmium secretion in bacteria SH225. CHEMOSPHERE 2023; 324:138373. [PMID: 36906001 DOI: 10.1016/j.chemosphere.2023.138373] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/17/2023] [Accepted: 03/08/2023] [Indexed: 06/18/2023]
Abstract
Cadmium (Cd), as one of the most carcinogenic substances, poses a great threat to human health. With the development of microbial remediation technology, the necessity for urgent research into the mechanism of Cd toxicity to bacteria has arisen. In this study, a highly Cd-tolerant strain (up to 225 mg/L) was isolated and purified from Cd-contaminated soil, which was identified by 16S rRNA as a strain of Stenotrophomonas sp., thus manually designated as SH225. By testing OD600 of the strain, we indicated that Cd concentrations below 100 mg/L had no discernible impact on the biomass of SH225. When the Cd concentration was over 100 mg/L, the cell growth was significantly inhibited, while the number of extracellular vesicles (EVs) was greatly elevated. After extraction, cell-secreted EVs were confirmed to contain large amounts of Cd cations, highlighting the crucial function of EVs in the Cd detoxification of SH225. Meanwhile, the TCA cycle was vastly enhanced, suggesting that the cells provided adequate energy supply for EVs transport. Thus, these findings emphasized the crucial role played by vesicles and TCA cycle in Cd detoxification.
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Affiliation(s)
- Tong Wang
- College of Environmental & Natural Resources, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Hangzhou 310058, China
| | - Yiran Yin
- College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jiawen Zhang
- College of Environmental & Natural Resources, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Hangzhou 310058, China
| | - Haoran Guan
- College of Environmental & Natural Resources, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Hangzhou 310058, China
| | - Jianming Xu
- College of Environmental & Natural Resources, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Hangzhou 310058, China
| | - Xingmei Liu
- College of Environmental & Natural Resources, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Hangzhou 310058, China.
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Al-Ansari MM. Influence of blue light on effective removal of arsenic by photosynthetic bacterium Rhodobacter sp. BT18. CHEMOSPHERE 2022; 292:133399. [PMID: 34952019 DOI: 10.1016/j.chemosphere.2021.133399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
Arsenic (As) contamination in an ecosystem has been a serious threat for the ecosystem as well as human health. Thus, the present study was established an eco-friendly remediation of As by using As resistant Rhodobacter sp. Accordingly, the growth of Rhodobacter sp. in As stress environment was assessed. Expectedly, enhanced growth order of the Rhodobacter sp., under As stress was found to be control >50 > 100 > 200 > 300 > 400 > 500 mg/L of As. In addition, the present study explored the influence of various light sources (Yellow, light blue, red, green and white) on growth and As removal mechanisms of Rhodobacter sp. The growth profile of the bacteria indicated that the light blue source showed an enhanced growth at 72 h of incubation. Based on optimization experiments, an increased As removal percentage rate was found to be at 87.5% at pH 7.0, 3% of glucose, 1% of citrate supplemented in the medium. The As resistant genetic pattern for arsenic transformation, the genes arsenate reductase (arsC), arsenite oxidase (aio) was investigated. To study the transcript level expression of arsC and aio genes were performed after exposure to different concentrations of As (50, 100, 150, and 200 mg/L) at different time intervals (24, 48, 72 and 96 h). The results showed that both arsC and aio were up regulated from 24 to 72 h and the down regulation was observed at 96 h. The obtained results indicated that the Rhodobacter sp., possess significant AS tolerance and removal potential would make it is a noteworthy candidate for future As remediation practices.
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Affiliation(s)
- Mysoon M Al-Ansari
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia.
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The periodic table of photosynthetic purple non-sulfur bacteria: intact cell-metal ions interactions. Photochem Photobiol Sci 2021; 21:101-111. [PMID: 34748197 DOI: 10.1007/s43630-021-00116-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 10/12/2021] [Indexed: 10/19/2022]
Abstract
Photosynthetic purple non-sulfur bacteria (PNB) have been widely utilized as model organisms to study bacterial photosynthesis. More recently, the remarkable resistance of these microorganisms to several metals ions called particular interest. As a result, several research efforts were directed toward clarifying the interactions of metal ions with PNB. The mechanisms of metal ions active uptake and bioabsorption have been studied in detail, unveiling that PNB enable harvesting and removing various toxic ions, thus fostering applications in environmental remediation. Herein, we present the most important achievements in the understanding of intact cell-metal ions interactions and the approaches utilized to study such processes. Following, the application of PNB-metal ions interactions toward metal removal from contaminated environments is presented. Finally, the possible coupling of PNB with abiotic electrodes to obtain biohybrid electrochemical systems is proposed as a sustainable pathway to tune and enhance metal removal and monitoring.
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Su YQ, Yuan S, Guo YC, Tan YY, Mao HT, Cao Y, Chen YE. Highly efficient and sustainable removal of Cr (VI) in aqueous solutions by photosynthetic bacteria supplemented with phosphor salts. CHEMOSPHERE 2021; 283:131031. [PMID: 34134043 DOI: 10.1016/j.chemosphere.2021.131031] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 04/06/2021] [Accepted: 05/22/2021] [Indexed: 06/12/2023]
Abstract
Photosynthetic bacteria have flexible metabolisms and strong environmental adaptability, and require cheap, but plentiful, energy supplements, which all enable their use in Cr(VI)-remediation. In this study, the effects of culture conditions on the total Cr removal rate were investigated for a newly identified strain of Rhodobacter sphaeroides SC01. The subcellular distribution and Cr(VI) reduction ability of four different cellular fractions were evaluated by scanning electron microscopy and transmission electron microscopy. Experiments indicated that the optimal culture conditions for total Cr removal included a culture temperature of 35 °C, pH of 7.20, an NaCl concentration of 5 g L-1, a light intensity of 4000 lx, and an initial cell concentration (OD680) of 0.15. In addition, most Cr was found in the cell membrane in the form of Cr (III) after reduction, while cell membranes had the highest Cr(VI) reduction rate (99%) compared to other cellular components. In addition, the physical and chemical properties of SC01 cells were characterized by FTIR, XPS, and XRD analyses, confirming that Cr was successfully absorbed on bacterial cell surfaces. CrPO4‧6H2O and Cr5(P3O10)3 precipitates were particularly identified by XRD analysis. After screening supplementation with five phosphor salts, Cr(VI) reduction due to bioprecipitation was improved by the addition of Na4P2O7 and (NaPO3)6 salts, with the Cr(VI)-reduction rate combined with Na4P2O7 addition being 15% higher than that of the control. Thus, this study proposes a new Cr(VI)-removal strategy based on the combined use of photosynthetic bacteria and phosphor salts, which importantly increases its potential application in treating wastewater.
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Affiliation(s)
- Yan-Qiu Su
- College of Life Science, Sichuan Normal University, Chengdu, China.
| | - Shu Yuan
- College of Life Sciences, Sichuan Agricultural University, Ya'an, China
| | - Yuan-Cheng Guo
- College of Life Science, Sichuan Normal University, Chengdu, China
| | - Yong-Yao Tan
- College of Life Science, Sichuan Normal University, Chengdu, China
| | - Hao-Tian Mao
- College of Life Sciences, Sichuan Agricultural University, Ya'an, China
| | - Yi Cao
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, China
| | - Yang-Er Chen
- College of Life Sciences, Sichuan Agricultural University, Ya'an, China.
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7
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Lu H, Zhang G, He S, Zhao R, Zhu D. Purple non-sulfur bacteria technology: a promising and potential approach for wastewater treatment and bioresources recovery. World J Microbiol Biotechnol 2021; 37:161. [PMID: 34436687 DOI: 10.1007/s11274-021-03133-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 08/18/2021] [Indexed: 11/24/2022]
Abstract
Shortage of water, energy, and bioresources in the world has led to the exploration of new technologies that achieve resource recovery from wastewater, which has become a new sustainable trend. Photosynthetic non-sulfur bacteria (PNSB), the most ancient photo microorganism, not only treats different wastewater types, but also generates PNSB cells, which are non-toxic bioresources and containing many value-added products. These bioresources can be used as raw materials in the agricultural, food, and medical industries. Therefore, PNSB or PNSB-based wastewater resource recovery technology can be simultaneously used to treat wastewater and produce useful bioresources. Compared with traditional wastewater treatment, this technology can reduce CO2 emissions, promote the N recovery ratio and prevent residual sludge disposal or generation. After being developed for over half a century, PNSB wastewater resource recovery technology is currently extended towards industrial applications. Here, this technology is comprehensively introduced in terms of (1) PNSB characteristics and metabolism; (2) PNSB wastewater treatment and bioresource recovery efficiency; (3) the relative factors influencing the performance of this technology, including light, oxygen, strains, wastewater types, hydraulic retention time, on wastewater treatment, and resource production; (4) PNSB value-added bioresources and their generation from wastewater; (5) the scale-up history of PNSB technology; (6) Finally, the future perspectives and challenges of this technology were also analysed and summarised.
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Affiliation(s)
- Haifeng Lu
- College of Water Resource and Civil Engineering, China Agriculture University, Beijing, 100083, China.,Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture, Beijing, 100083, China
| | - Guangming Zhang
- Key Laboratory of Environmental Biotechnology, China Academy of Science, Shuangqing Road, Beijing, 100084, China. .,School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China.
| | - Shichao He
- College of Water Resource and Civil Engineering, China Agriculture University, Beijing, 100083, China.,Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture, Beijing, 100083, China
| | - Ruihan Zhao
- College of Water Resource and Civil Engineering, China Agriculture University, Beijing, 100083, China.,Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture, Beijing, 100083, China
| | - Da Zhu
- Nan Tong Ju Yi Cheng Guang Biotechnology Co. LTD., Nantong, 226321, China
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8
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Wu P, Zhang X, Niu T, Wang Y, Liu R, Zhang Y. The imidacloprid remediation, soil fertility enhancement and microbial community change in soil by Rhodopseudomonas capsulata using effluent as carbon source. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 267:114254. [PMID: 32911333 DOI: 10.1016/j.envpol.2020.114254] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 02/09/2020] [Accepted: 02/21/2020] [Indexed: 05/20/2023]
Abstract
The effects of Rhodopseudomonas capsulata (R. capsulata) in the treated effluent of soybean processing wastewater (SPW) on the remediation of imidacloprid in soil, soil fertility, and the microbial community structure in soil were studied. Compared with the control group, with the addition of effluent containing R. capsulata, imidacloprid was effectively removed, soil fertility was enhanced, and the microbial community structure was improved. Molecular analysis indicated that imidacloprid could exert induction effects on expression of cpm gene and regulation effects on the synthesis of cytochrome P450 monooxygenases (P450) by activating HKs gene in two-component system (TCS). For R. capsulata, this induction process required 1 day. The synthesis of P450 occurred 1 day after inoculation, because R. capsulata are a type of archaea and imidacloprid is an environmental stress. Before expression of the cpm gene and synthesis of P450, R. capsulata need a period of time to adapt to external imidacloprid stimulation. However, the lack of organic matter in the soil cannot sustain R. capsulata growth for more than 1 day. In four groups with added effluent, the remaining organic matter in the effluent provided a sufficient carbon source and energy for R. capsulata. Five days later, the microbial community structure was improved by R. capsulata in the soil. The new technique could be used to remediate imidacloprid, enhance soil fertility, treat SPW and realize the recycling and reuse of wastewater and R. capsulata cells.
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Affiliation(s)
- Pan Wu
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Xuewei Zhang
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
| | - Tong Niu
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
| | - Yanling Wang
- Department of Anesthesiology, The Third Affiliated Hospital of SunYat-Sen University, Guangzhou, 510630, China
| | - Rijia Liu
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China.
| | - Ying Zhang
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China.
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Wu P, Liu Y, Song X, Wang Y, Sheng L, Wang H, Zhang Y. Rhodopseudomonas sphaeroides treating mesosulfuron-methyl waste-water. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 262:114166. [PMID: 32443208 DOI: 10.1016/j.envpol.2020.114166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 01/23/2020] [Accepted: 02/10/2020] [Indexed: 06/11/2023]
Abstract
The soybean processing wastewater (SPW) supplementation to facilitate the simultaneously treatment (SPW and mesosulfuron-methyl) of wastewater and production of biological substances by Rhodopseudomonas sphaeroides (R. sphaeroides) was discussed. Compared with the control group, with the addition of SPW, mesosulfuron-methyl was removed, and the yields of single-cell proteins, carotenoids, and bacteriochlorophyll were increased. In the 3 mg/L dose group, the mesosulfuron-methyl removal rate reached 97% after 5 days. Molecular analysis revealed that mesosulfuron-methyl exhibited induction effects on expression of the cpm gene and regulation effects on the synthesis of cytochrome P450 monooxygenases (P450) by activating HKs gene in TCS signal transduction pathway. For R. sphaeroides, this induction process required 1 day. The synthesis of P450 occurred 1 day after inoculation. Prior to expressing cpm gene and synthesizing P450, R. sphaeroides need a period of time to adapt to external mesosulfuron-methyl stimulation. However, the R. sphaeroides growth could not be maintained for more than 1 day due to the lack of organic matter in the raw wastewater. The SPW supplementation provided a sufficient carbon source in four groups with added SPW. After 5 days, R. sphaeroides became the dominant microflora in the wastewater. This new method could complete the treatment of mixed wastewater, the increased of biological substances output and the reuse of wastewater and R. sphaeroides cells as resources at the same time.
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Affiliation(s)
- Pan Wu
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Yuxin Liu
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Xue Song
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Yanling Wang
- Department of Anesthesiology, The Third Affiliated Hospital of SunYat-Sen University, Guangzhou, 510630, China
| | - Luying Sheng
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China.
| | - Haimei Wang
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China.
| | - Ying Zhang
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China.
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10
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Su YQ, Zhao YJ, Zhang WJ, Chen GC, Qin H, Qiao DR, Chen YE, Cao Y. Removal of mercury(II), lead(II) and cadmium(II) from aqueous solutions using Rhodobacter sphaeroides SC01. CHEMOSPHERE 2020; 243:125166. [PMID: 31756653 DOI: 10.1016/j.chemosphere.2019.125166] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 10/09/2019] [Accepted: 10/20/2019] [Indexed: 06/10/2023]
Abstract
Microorganisms and microbial products can be highly efficient in uptaking soluble and particulate forms of heavy metals, particularly from solutions. In this study, the removal efficiency, oxidative damage, antioxidant system, and the possible removal mechanisms were investigated in Rhodobacter (R.) sphaeroides SC01 under mercury (Hg), lead (Pb) and cadmium (Cd) stress. The results showed that SC01 had the highest removal rates (98%) of Pb among three heavy metals. Compared with Hg and Cd stress, Pb stress resulted in a lower levels of reactive oxygen species (ROS) and cell death. In contrast, the activities of four antioxidant enzymes in SC01 under Pb stress was higher than that of Hg and Cd stress. Furthermore, the analysis from fourier transform infrared spectroscopy indicated that complexation of Pb with hydroxyl, amid and phosphate groups was found in SC01 under Pb stress. In addition, X-ray diffraction analysis showed that precipitate of lead phosphate hydroxide was produced on the cell surface in SC01 exposed to Pb stress. Therefore, these results suggested that SC01 had good Pb removal ability by biosorption and precipitation and will be potentially useful for removal of Pb in industrial effluents.
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Affiliation(s)
- Yan-Qiu Su
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610064, China
| | - Yang-Juan Zhao
- College of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China
| | - Wei-Jia Zhang
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610064, China
| | - Guo-Cheng Chen
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610064, China
| | - Han Qin
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610064, China
| | - Dai-Rong Qiao
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610064, China
| | - Yang-Er Chen
- College of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China.
| | - Yi Cao
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610064, China.
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11
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Gaffney EM, Grattieri M, Beaver K, Pham J, McCartney C, Minteer SD. Unveiling salinity effects on photo-bioelectrocatalysis through combination of bioinformatics and electrochemistry. Electrochim Acta 2020; 337. [PMID: 32308212 DOI: 10.1016/j.electacta.2020.135731] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Little is known about the adaptation strategies utilized by photosynthetic microorganisms to cope with salinity changes happening in the environment, and the effects on microbial electrochemical technologies. Herein, bioinformatics analysis revealed a metabolism shift in Rhodobacter capsulatus resulting from salt stress, with changes in gene expression allowing accumulation of compatible solutes to balance osmotic pressure, together with the up-regulation of the nitrogen fixation cycle, an electron sink of the photosynthetic electron transfer chain. Using the transcriptome evidence of hindered electron transfer in the photosynthetic electron transport chain induced by adaption to salinity, increased understanding of photo-bioelectrocatalysis under salt stress is achieved. Accumulation of glycine-betaine allows immediate tuning of salinity tolerance but does not provide cell stabilization, with a 40 ± 20% loss of photo-bioelectrocatalysis in a 60 min time scale. Conversely, exposure to or inducing the expression of the Rhodobacter capsulatus gene transfer agent tunes salinity tolerance and increases cell stability. This work provides a proof of concept for the combination of bioinformatics and electrochemical tools to investigate microbial electrochemical systems, opening exciting future research opportunities.
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Affiliation(s)
- Erin M Gaffney
- Department of Chemistry, University of Utah, 315 S 1400 E Room 2020, Salt Lake City, 84112, Utah, USA
| | - Matteo Grattieri
- Department of Chemistry, University of Utah, 315 S 1400 E Room 2020, Salt Lake City, 84112, Utah, USA
| | - Kevin Beaver
- Department of Chemistry, University of Utah, 315 S 1400 E Room 2020, Salt Lake City, 84112, Utah, USA
| | - Jennie Pham
- Department of Chemistry, University of Utah, 315 S 1400 E Room 2020, Salt Lake City, 84112, Utah, USA
| | - Caitlin McCartney
- Department of Chemistry, University of Utah, 315 S 1400 E Room 2020, Salt Lake City, 84112, Utah, USA.,Departments of Chemistry, Brown University, 324 Brook Street Box H, Providence, 02912, Rhode Island, USA
| | - Shelley D Minteer
- Department of Chemistry, University of Utah, 315 S 1400 E Room 2020, Salt Lake City, 84112, Utah, USA
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12
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Grattieri M. Purple bacteria photo-bioelectrochemistry: enthralling challenges and opportunities. Photochem Photobiol Sci 2020; 19:424-435. [DOI: 10.1039/c9pp00470j] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Perspective of research directions exploring purple bacteria photo-bioelectrochemistry: from harvesting photoexcited electrons to bioelectrochemical systems development.
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13
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Wu P, Zhang Q, Wang Y, Zhang Y, Chen Z, Cao B, Wu Y, Zhu F, Li N. RETRACTED: Clothianidin wastewater treatment and the accumulation of high-value biochemical by Rhodopseudomonas spheroides. BIORESOURCE TECHNOLOGY 2019; 294:122073. [PMID: 31521982 DOI: 10.1016/j.biortech.2019.122073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/21/2019] [Accepted: 08/24/2019] [Indexed: 06/10/2023]
Abstract
This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Authors and the Editor-in-Chief. The paper is retracted because of a high level of duplication of "Rhodopseudomonas palustris wastewater treatment: cyhalofop-butyl removal, biochemicals production and mathematical model establishment. Bioresource. Tech. 2019, 282: 390-397 As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. The first author, Pan Wu, takes full responsibility for these actions, a stance supported by Dalian Minzu University and Northeast Agricultural University, Harbin, where the research took place.
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Affiliation(s)
- Pan Wu
- School of Environment and Resources, Dalian Minzu University, Dalian116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin150030, China
| | - Qian Zhang
- School of Environment and Resources, Dalian Minzu University, Dalian116600, China
| | - Yanling Wang
- Department of Anesthesiology, the Third Affiliated Hospital of SunYat-Sen University, Guangzhou510630, China
| | - Ying Zhang
- School of Environment and Resources, Dalian Minzu University, Dalian116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin150030, China.
| | - Zhaobo Chen
- School of Environment and Resources, Dalian Minzu University, Dalian116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin150030, China
| | - Bo Cao
- School of Environment and Resources, Dalian Minzu University, Dalian116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin150030, China
| | - Yuan Wu
- School of Environment and Resources, Dalian Minzu University, Dalian116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin150030, China
| | - Feifei Zhu
- Forest and Wastewater Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang110164, China
| | - Ning Li
- School of Environment and Resources, Dalian Minzu University, Dalian116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin150030, China
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14
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Wu P, Xie L, Mo W, Wang B, Ge H, Sun X, Tian Y, Zhao R, Zhu F, Zhang Y, Wang Y. The biodegradation of carbaryl in soil with Rhodopseudomonas capsulata in wastewater treatment effluent. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 249:109226. [PMID: 31442909 DOI: 10.1016/j.jenvman.2019.06.127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 06/20/2019] [Accepted: 06/30/2019] [Indexed: 06/10/2023]
Abstract
In this study, the effects of Rhodopseudomonas capsulata present in wastewater effluent on the biodegradation of carbaryl in soil and improvement of soil fertility were investigated. Compared to control treatment, carbaryl was removed efficiently and soil fertility was remediated with the addition of effluent containing R. capsulata. Molecular analysis revealed that carbaryl induced carbaryl hydrolase gene expression to synthesize carbaryl hydrolase through activating MAPKKKs, MAPKKs, MAPKs genes in MAPK signal transduction pathway. The induction and secretion of carbaryl hydrolase occur after one day in R. capsulata, which can be attributed to its characteristics as an ancient bacteria, which require acclimatization to carbaryl before gene induction. However, lack of organics in soil and control treatment could not maintain R. capsulata growth for over one day. The residual organics in the effluent provided sufficient carbon source and energy for R. capsulata under four effluent treatments. This new method resulted in the remediation of carbaryl pollution and improvement of soil fertility and soybean processing wastewater treatment simultaneously, as well as the reutilization of wastewater and R. capsulata as sludge. Meanwhile, the high-order non-linear mathematical model about carbaryl removal rate was established.
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Affiliation(s)
- Pan Wu
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Liying Xie
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
| | - Wentao Mo
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
| | - Bing Wang
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
| | - Hui Ge
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
| | - Xiaodong Sun
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
| | - Ying Tian
- Key Laboratory of Mariculture & Stock Enhancement in North China Sea, Ministry of Agriculture, Dalian Ocean University, Dalian, 116023, Liaoning, China
| | - Rou Zhao
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
| | - Feifei Zhu
- Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110164, China
| | - Ying Zhang
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China.
| | - Yanling Wang
- Department of Anesthesiology, The Third Affiliated Hospital of SunYat-Sen University, Guangzhou, 510630, China.
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15
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Wu P, Han Z, Mo W, Wu X, Chen Z, Zhang Y, Wang Y, Cui Y, Dong Y, Sun H, Zou X. Soybean processing wastewater supported the removal of propyzamide and biochemical accumulation from wastewater by Rhodopseudomonas capsulata. Bioprocess Biosyst Eng 2019; 42:1375-1384. [PMID: 31172262 DOI: 10.1007/s00449-019-02137-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 12/15/2018] [Indexed: 11/25/2022]
Abstract
Simultaneous (SPW and propyzamide) wastewater treatment and the production of biochemicals by Rhodopseudomonas capsulata (R. capsulata) were investigated with supplement of soybean processing wastewater (SPW). Compared to control group, propyzamide was removed and biochemicals production were enhanced with the supplement of SPW. Propyzamide induced camH gene expression through activating MAPKKKs gene in MAPK signal transduction pathway. The induction of camH gene and CamH occurs after 1 day for R. capsulata. However, lack of organics in original wastewater did not maintain R. capsulata growth for over 1 day. The supplement of SPW provided sufficient carbon source for R. capsulata under three addition dosages. This new method resulted in the mixed (SPW and propyzamide) wastewater treatment and improvement of biochemicals simultaneously, as well as the realization of reutilization of wastewater and R. capsulata as sludge. Meanwhile, high-order nonlinear mathematical model of the relationship between propyzamide removal rate, Xt and Xt/r, was established.
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Affiliation(s)
- Pan Wu
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
- School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Ziqiao Han
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
| | - Wentao Mo
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
| | - Xiaozhen Wu
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
| | - Zhaobo Chen
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China.
- School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China.
| | - Ying Zhang
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China.
- School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China.
| | - Yanling Wang
- Department of Anesthesiology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, China
| | - Yubo Cui
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
| | - Yuying Dong
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
- School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Hongjie Sun
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
- School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Xuejun Zou
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
- School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China
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16
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Šrut M, Menke S, Höckner M, Sommer S. Earthworms and cadmium - Heavy metal resistant gut bacteria as indicators for heavy metal pollution in soils? ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 171:843-853. [PMID: 30660978 DOI: 10.1016/j.ecoenv.2018.12.102] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 12/26/2018] [Accepted: 12/29/2018] [Indexed: 05/25/2023]
Abstract
Preservation of the soil resources stability is of high importance for ecosystems, particularly in the current era of environmental change, which presents a severe pollution burden (e.g. by heavy metals) to soil fauna. Gut microbiomes are becoming recognized as important players in organism health, with comprehension of their perturbations in the polluted environment offering new insights into the nature and extent of heavy metal effects on the health of soil biota. Our aim was to investigate the effect of environmentally relevant heavy metal concentrations of cadmium (Cd) on the earthworm (Lumbricus terrestris) gut microbiota. Our results revealed that Cd exposure led to perturbations of earthworm gut microbiota with an increase in bacteria previously described as heavy metal resistant or able to bind heavy metals, revealing the potential of the earthworm-gut microbiota system in overcoming human-caused heavy metal pollution. Furthermore, an 'indicator species analysis' linked the bacterial genera Paenibacillus, Flavobacterium and Pseudomonas, with Cd treatment, suggesting these bacterial taxa as biomarkers of exposure in earthworms inhabiting Cd-stressed soils. The results of this study help to understand the impact of anthropogenic disturbance on soil fauna health and will have implications for environmental monitoring and protection of soil resources.
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Affiliation(s)
- Maja Šrut
- University of Zagreb, Faculty of Science, Department of Biology, Rooseveltov trg 6, 10000 Zagreb, Croatia.
| | - Sebastian Menke
- University of Ulm, Institute of Evolutionary Ecology and Conservation Genomics, Helmholtzstr. 10/1, 89081 Ulm, Germany
| | - Martina Höckner
- University of Innsbruck, Institute of Zoology, Technikerstr. 25, 6020 Innsbruck, Austria
| | - Simone Sommer
- University of Ulm, Institute of Evolutionary Ecology and Conservation Genomics, Helmholtzstr. 10/1, 89081 Ulm, Germany
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17
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Draft Genome Sequences of Four Rhodobacter sphaeroides Strains Isolated from a Marine Ecosystem. Microbiol Resour Announc 2019; 8:MRA01648-18. [PMID: 30687844 PMCID: PMC6346176 DOI: 10.1128/mra.01648-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 12/13/2018] [Indexed: 11/20/2022] Open
Abstract
Rhodobacter sphaeroides is an alphaproteobacterium found in freshwater and marine ecosystems. To better understand the metabolic diversity within this species, we isolated and sequenced four R. sphaeroides isolates obtained from Trunk River in Woods Hole, Massachusetts. Rhodobacter sphaeroides is an alphaproteobacterium found in freshwater and marine ecosystems. To better understand the metabolic diversity within this species, we isolated and sequenced four R. sphaeroides isolates obtained from Trunk River in Woods Hole, Massachusetts. Here, we report the draft genome sequences of R. sphaeroides AB24, AB25, AB27, and AB29.
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18
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Grattieri M, Beaver K, Gaffney E, Minteer SD. Tuning purple bacteria salt-tolerance for photobioelectrochemical systems in saline environments. Faraday Discuss 2019; 215:15-25. [DOI: 10.1039/c8fd00160j] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Fast adaptation ofRhodobacter capsulatusto increasing salinities opens possibilities for photo-bioelectrochemical systems development for saline environments.
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Affiliation(s)
- Matteo Grattieri
- Departments of Chemistry and Materials Science & Engineering
- University of Utah
- Salt Lake City
- USA
| | - Kevin Beaver
- Departments of Biology and Chemistry
- Lebanon Valley College
- Annville
- USA
| | - Erin M. Gaffney
- Departments of Chemistry and Materials Science & Engineering
- University of Utah
- Salt Lake City
- USA
| | - Shelley D. Minteer
- Departments of Chemistry and Materials Science & Engineering
- University of Utah
- Salt Lake City
- USA
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19
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Design and modelling of a photo-electrochemical transduction system based on solubilized photosynthetic reaction centres. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2018.09.198] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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20
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Ragni R, Leone G, la Gatta S, Rizzo G, Lo Presti M, De Leo V, Milano F, Trotta M, Farinola GM. A heptamethine cyanine dye suitable as antenna in biohybrids based on bacterial photosynthetic reaction center. ACTA ACUST UNITED AC 2018. [DOI: 10.1557/adv.2018.640] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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21
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Field EK, Blaskovich JP, Peyton BM, Gerlach R. Carbon-dependent chromate toxicity mechanism in an environmental Arthrobacter isolate. JOURNAL OF HAZARDOUS MATERIALS 2018; 355:162-169. [PMID: 29800910 DOI: 10.1016/j.jhazmat.2018.05.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 05/08/2018] [Accepted: 05/10/2018] [Indexed: 06/08/2023]
Abstract
Arthrobacter spp. are widespread in soil systems and well-known for their Cr(VI) reduction capabilities making them attractive candidates for in situ bioremediation efforts. Cellulose drives carbon flow in soil systems; yet, most laboratory studies evaluate Arthrobacter-Cr(VI) interactions solely with nutrient-rich media or glucose. This study aims to determine how various cellulose degradation products and biostimulation substrates influence Cr(VI) toxicity, reduction, and microbial growth of an environmental Arthrobacter sp. isolate. Laboratory culture-based studies suggest there is a carbon-dependent Cr(VI) toxicity mechanism that affects subsequent Cr(VI) reduction by strain LLW01. Strain LLW01 could only grow in the presence of, and reduce, 50 μM Cr(VI) when glucose or lactate were provided. Compared to lactate, Cr(VI) was at least 30-fold and 10-fold more toxic when ethanol or butyrate was the sole carbon source, respectively. The addition of sulfate mitigated toxicity somewhat, but had no effect on the extent of Cr(VI) reduction. Cell viability studies indicated that a small fraction of cells were viable after 8 days suggesting cell growth and subsequent Cr(VI) reduction may resume. These results suggest when designing bioremediation strategies with Arthrobacter spp. such as strain LLW01, carbon sources such as glucose and lactate should be considered over ethanol and butyrate.
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Affiliation(s)
- Erin K Field
- Department of Biology, East Carolina University, Greenville, NC, 27858, United States; Center for Biofilm Engineering, Montana State University, Bozeman, MT, 59717, United States.
| | - John P Blaskovich
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, 59717, United States; Department of Chemical and Biological Engineering, Montana State University, Bozeman, MT, 59717, United States
| | - Brent M Peyton
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, 59717, United States; Department of Chemical and Biological Engineering, Montana State University, Bozeman, MT, 59717, United States
| | - Robin Gerlach
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, 59717, United States; Department of Chemical and Biological Engineering, Montana State University, Bozeman, MT, 59717, United States.
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22
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Italiano F, Agostiano A, Belviso BD, Caliandro R, Carrozzini B, Comparelli R, Melillo MT, Mesto E, Tempesta G, Trotta M. Interaction between the photosynthetic anoxygenic microorganism Rhodobacter sphaeroides and soluble gold compounds. From toxicity to gold nanoparticle synthesis. Colloids Surf B Biointerfaces 2018; 172:362-371. [PMID: 30189387 DOI: 10.1016/j.colsurfb.2018.06.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 06/06/2018] [Indexed: 02/08/2023]
Abstract
Biological processes using microorganisms for nanoparticle synthesis are appealing as eco-friendly nanofactories. The response of the photosynthetic bacterium Rhodobacter sphaeroides to gold exposure and its reducing capability of Au(III) to produce stable gold nanoparticles (AuNPs), using metabolically active bacteria and quiescent biomass, is reported in this study. In the former case, bacterial cells were grown in presence of gold chloride at physiological pH. Gold exposure was found to cause a significant increase of the lag-phase duration at concentrations higher than 10 μM, suggesting the involvement of a resistance mechanism activated by Au(III). Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy/Energy Dispersive X-ray Spectrometry (SEM/EDS) analysis of bacterial cells confirmed the extracellular formation of AuNPs. Further studies were carried out on metabolically quiescent biomass incubated with gold chloride solution. The biosynthesized AuNPs were spherical in shape with an average size of 10 ± 3 nm, as analysed by Transmission Electron Microscopy (TEM). The nanoparticles were hydrophilic and stable against aggregation for several months. In order to identify the functional groups responsible for the reduction and stabilization of nanoparticles, AuNPs were analysed by Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy, X-ray Photoelectron Spectroscopy (XPS), X-ray Fluorescence Spectrometry (XRF) and X-ray Absorption Spectroscopy (XAS) measurements. The obtained results indicate that gold ions bind to functional groups of cell membrane and are subsequently reduced by reducing sugars to gold nanoparticles and capped by a protein/peptide coat. Gold nanoparticles demonstrated to be efficient homogeneous catalysts in the degradation of nitroaromatic compounds.
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Affiliation(s)
- Francesca Italiano
- CNR - Istituto per i Processi Chimico-Fisici, Sezione di Bari, via E. Orabona, 4, 70126, Bari, Italy.
| | - Angela Agostiano
- CNR - Istituto per i Processi Chimico-Fisici, Sezione di Bari, via E. Orabona, 4, 70126, Bari, Italy; Università degli Studi di Bari "Aldo Moro", Dipartimento di Chimica, via E. Orabona, 4, 70126, Bari, Italy
| | | | - Rocco Caliandro
- CNR - Istituto di Cristallografia, via G. Amendola, 122/O, 70126, Bari, Italy
| | | | - Roberto Comparelli
- CNR - Istituto per i Processi Chimico-Fisici, Sezione di Bari, via E. Orabona, 4, 70126, Bari, Italy
| | - Maria Teresa Melillo
- CNR - Istituto per la Protezione Sostenibile delle Piante, Sezione di Bari, Via G. Amendola, 122/D, 70126, Bari, Italy
| | - Ernesto Mesto
- Università degli Studi di Bari "Aldo Moro", Dipartimento di Scienze della Terra e Geoambientali, Via E. Orabona 4, 70126, Bari, Italy
| | - Gioacchino Tempesta
- Università degli Studi di Bari "Aldo Moro", Dipartimento di Scienze della Terra e Geoambientali, Via E. Orabona 4, 70126, Bari, Italy
| | - Massimo Trotta
- CNR - Istituto per i Processi Chimico-Fisici, Sezione di Bari, via E. Orabona, 4, 70126, Bari, Italy
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23
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Sipka G, Kis M, Maróti P. Characterization of mercury(II)-induced inhibition of photochemistry in the reaction center of photosynthetic bacteria. PHOTOSYNTHESIS RESEARCH 2018; 136:379-392. [PMID: 29285578 DOI: 10.1007/s11120-017-0474-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 12/20/2017] [Indexed: 06/07/2023]
Abstract
Mercuric contamination of aqueous cultures results in impairment of viability of photosynthetic bacteria primarily by inhibition of the photochemistry of the reaction center (RC) protein. Isolated reaction centers (RCs) from Rhodobacter sphaeroides were exposed to Hg2+ ions up to saturation concentration (~ 103 [Hg2+]/[RC]) and the gradual time- and concentration-dependent loss of the photochemical activity was monitored. The vast majority of Hg2+ ions (about 500 [Hg2+]/[RC]) had low affinity for the RC [binding constant Kb ~ 5 mM-1] and only a few (~ 1 [Hg2+]/[RC]) exhibited strong binding (Kb ~ 50 μM-1). Neither type of binding site had specific and harmful effects on the photochemistry of the RC. The primary charge separation was preserved even at saturation mercury(II) concentration, but essential further steps of stabilization and utilization were blocked already in the 5 < [Hg2+]/[RC] < 50 range whose locations were revealed. (1) The proton gate at the cytoplasmic site had the highest affinity for Hg2+ binding (Kb ~ 0.2 μM-1) and blocked the proton uptake. (2) Reduced affinity (Kb ~ 0.05 μM-1) was measured for the mercury(II)-binding site close to the secondary quinone that resulted in inhibition of the interquinone electron transfer. (3) A similar affinity was observed close to the bacteriochlorophyll dimer causing slight energetic changes as evidenced by a ~ 30 nm blue shift of the red absorption band, a 47 meV increase in the redox midpoint potential, and a ~ 20 meV drop in free energy gap of the primary charge pair. The primary quinone was not perturbed upon mercury(II) treatment. Although the Hg2+ ions attack the RC in large number, the exertion of the harmful effect on photochemistry is not through mass action but rather a couple of well-defined targets. Bound to these sites, the Hg2+ ions can destroy H-bond structures, inhibit protein dynamics, block conformational gating mechanisms, and modify electrostatic profiles essential for electron and proton transfer.
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Affiliation(s)
- Gábor Sipka
- Department of Medical Physics, University of Szeged, Rerrich Béla tér 1, Szeged, 6720, Hungary
- Department of Plant Biology, Hungarian Academy of Science, Biological Research Centre, Szeged, Hungary
| | - Mariann Kis
- Department of Medical Physics, University of Szeged, Rerrich Béla tér 1, Szeged, 6720, Hungary
| | - Péter Maróti
- Department of Medical Physics, University of Szeged, Rerrich Béla tér 1, Szeged, 6720, Hungary.
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24
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Sharma P, Melkania U. Impact of heavy metals on hydrogen production from organic fraction of municipal solid waste using co-culture of Enterobacter aerogenes and E. Coli. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 75:289-296. [PMID: 29426722 DOI: 10.1016/j.wasman.2018.02.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 02/01/2018] [Accepted: 02/02/2018] [Indexed: 06/08/2023]
Abstract
In the present study, the effect of heavy metals (lead, mercury, copper, and chromium) on the hydrogen production from the organic fraction of municipal solid waste (OFMSW) was investigated using co-culture of facultative anaerobes Enterobacter aerogenes and E. coli. Heavy metals were applied at concentration range of 0.5, 1, 2, 5, 10, 20, 50 and 100 mg/L. The results revealed that lead, mercury, and chromium negatively affected hydrogen production for the range of concentrations applied. Application of copper slightly enhanced hydrogen production at low concentration and resulted in the hydrogen yield of 36.0 mLH2/gCarboinitial with 10 mg/L copper supplementation as compared to 24.2 mLH2/gCarboinitial in control. However, the higher concentration of copper (>10 mg/L) declined hydrogen production. Hydrogen production inhibition potential of heavy metals can be arranged in the following increasing order: Cu2+ < Cr6+ < Pb2+ < Hg2+. COD removal rate and volatile fatty acid generation efficiencies were also significantly affected by heavy metal addition. Thus, the present study reveals that the presence of heavy metals in the feedstock is detrimental for the hydrogen production. Therefore, it is essential to remove the toxic heavy metals prior to anaerobic digestion.
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Affiliation(s)
- Preeti Sharma
- Department of Environmental Science, GB Pant University of Agriculture and Technology, Pantnagar 263145, Uttarakhand, India.
| | - Uma Melkania
- Department of Environmental Science, GB Pant University of Agriculture and Technology, Pantnagar 263145, Uttarakhand, India
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25
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Pérez V, Dorador C, Molina V, Yáñez C, Hengst M. Rhodobacter sp. Rb3, an aerobic anoxygenic phototroph which thrives in the polyextreme ecosystem of the Salar de Huasco, in the Chilean Altiplano. Antonie van Leeuwenhoek 2018; 111:1449-1465. [PMID: 29569108 DOI: 10.1007/s10482-018-1067-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 03/16/2018] [Indexed: 10/17/2022]
Abstract
The Salar de Huasco is an evaporitic basin located in the Chilean Altiplano, which presents extreme environmental conditions for life, i.e. high altitude (3800 m.a.s.l.), negative water balance, a wide salinity range, high daily temperature changes and the occurrence of the highest registered solar radiation on the planet (> 1200 W m-2). This ecosystem is considered as a natural laboratory to understand different adaptations of microorganisms to extreme conditions. Rhodobacter, an anoxygenic aerobic phototrophic bacterial genus, represents one of the most abundant groups reported based on taxonomic diversity surveys in this ecosystem. The bacterial mat isolate Rhodobacter sp. strain Rb3 was used to study adaptation mechanisms to stress-inducing factors potentially explaining its success in a polyextreme ecosystem. We found that the Rhodobacter sp. Rb3 genome was characterized by a high abundance of genes involved in stress tolerance and adaptation strategies, among which DNA repair and oxidative stress were the most conspicuous. Moreover, many other molecular mechanisms associated with oxidative stress, photooxidation and antioxidants; DNA repair and protection; motility, chemotaxis and biofilm synthesis; osmotic stress, metal, metalloid and toxic anions resistance; antimicrobial resistance and multidrug pumps; sporulation; cold shock and heat shock stress; mobile genetic elements and toxin-antitoxin system were detected and identified as potential survival mechanism features in Rhodobacter sp. Rb3. In total, these results reveal a wide set of strategies used by the isolate to adapt and thrive under environmental stress conditions as a model of polyextreme environmental resistome.
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Affiliation(s)
- Vilma Pérez
- Laboratory of Molecular Ecology and Applied Microbiology, Departamento de Ciencias Farmacéuticas, Universidad Católica del Norte, Antofagasta, Chile.,Centre for Biotechnology & Bioengineering (CeBiB), Santiago, Chile
| | - Cristina Dorador
- Centre for Biotechnology & Bioengineering (CeBiB), Santiago, Chile.,Laboratorio de Complejidad Microbiana y Ecología Funcional, Instituto Antofagasta & Departamento de Biotecnología, Universidad de Antofagasta, Antofagasta, Chile
| | - Verónica Molina
- Departamento de Biología, Facultad de Ciencias Naturales y Exactas, Universidad de Playa Ancha, Valparaiso, Chile
| | - Carolina Yáñez
- Laboratorio Microbiología, Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaiso, Chile
| | - Martha Hengst
- Laboratory of Molecular Ecology and Applied Microbiology, Departamento de Ciencias Farmacéuticas, Universidad Católica del Norte, Antofagasta, Chile. .,Centre for Biotechnology & Bioengineering (CeBiB), Santiago, Chile.
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Jacquiod S, Cyriaque V, Riber L, Al-Soud WA, Gillan DC, Wattiez R, Sørensen SJ. Long-term industrial metal contamination unexpectedly shaped diversity and activity response of sediment microbiome. JOURNAL OF HAZARDOUS MATERIALS 2018; 344:299-307. [PMID: 29055834 DOI: 10.1016/j.jhazmat.2017.09.046] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 08/11/2017] [Accepted: 09/25/2017] [Indexed: 05/19/2023]
Abstract
Metal contamination poses serious biotoxicity and bioaccumulation issues, affecting both abiotic conditions and biological activity in ecosystem trophic levels, especially sediments. The MetalEurop foundry released metals directly into the French river "la Deûle" during a century, contaminating sediments with a 30-fold increase compared to upstream unpolluted areas (Férin, Sensée canal). Previous metaproteogenomic work revealed phylogenetically analogous, but functionally different microbial communities between the two locations. However, their potential activity status in situ remains unknown. The present study respectively compares the structures of both total and active fractions of sediment prokaryotic microbiomes by coupling DNA and RNA-based sequencing approaches at the polluted MetalEurop site and its upstream control. We applied the innovative ecological concept of Functional Response Groups (FRGs) to decipher the adaptive tolerance range of the communities through characterization of microbial lifestyles and strategists. The complementing use of DNA and RNA sequencing revealed indications that metals selected for mechanisms such as microbial facilitation via "public-good" providing bacteria, Horizontal Gene Transfer (HGT) and community coalescence, overall resulting in an unexpected higher microbial diversity at the polluted site.
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Affiliation(s)
- Samuel Jacquiod
- Section of Microbiology, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen Ø, 1, Bygning, 1-1-215, Denmark.
| | - Valentine Cyriaque
- Proteomics and Microbiology Lab, Research Institute for Biosciences, UMONS, avenue du Champs de Mars 6, 7000 Mons, Belgium.
| | - Leise Riber
- Section of Functional Genomics, Department of Biology, University of Copenhagen, Ole Maaløesvej 5, 2200 Copenhagen N, Denmark.
| | - Waleed Abu Al-Soud
- Section of Microbiology, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen Ø, 1, Bygning, 1-1-215, Denmark.
| | - David C Gillan
- Proteomics and Microbiology Lab, Research Institute for Biosciences, UMONS, avenue du Champs de Mars 6, 7000 Mons, Belgium.
| | - Ruddy Wattiez
- Proteomics and Microbiology Lab, Research Institute for Biosciences, UMONS, avenue du Champs de Mars 6, 7000 Mons, Belgium.
| | - Søren J Sørensen
- Section of Microbiology, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen Ø, 1, Bygning, 1-1-215, Denmark.
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Su YQ, Zhao YJ, Wu N, Chen YE, Zhang WJ, Qiao DR, Cao Y. Chromium removal from solution by five photosynthetic bacteria isolates. Appl Microbiol Biotechnol 2017; 102:1983-1995. [PMID: 29279958 DOI: 10.1007/s00253-017-8690-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 12/01/2017] [Accepted: 12/02/2017] [Indexed: 01/26/2023]
Abstract
Biological method has been recognized as a low-cost and ecofriendly approach for removing heavy metals from aqueous wastes. In this study, the ability of five photosynthetic bacteria isolates (strains labeled SC01, HN02, SC05, JS01, and YN01) was examined for their ability to remove Cr from Cr-containing solutions. Furthermore, the possible removal mechanisms were elucidated by comparing chromium removal rates, antioxidant reaction, and accumulation of reactive oxygen species (ROS). Among the five bacteria, strains SC01 and SC05 presented the highest removal rates of chromium ions and the activity of cysteine desulfhydrase under Cr stress. They also showed lower levels of ROS and cell death than the other three bacteria strains under Cr stress. In addition, total bacteriochlorophyll content and activities of six antioxidant enzymes in SC01 were highest among these selected strains. On the contrary, strain HN02 presented the lowest level of Cr removal and the lowest activities of antioxidant enzymes. It also exhibited the highest level of ROS under Cr(VI) stress. Overall, these results show that the strains SC01 and SC05 have good Cr removal ability and could be used for removal of Cr in industrial effluents.
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Affiliation(s)
- Yan-Qiu Su
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, China.,Tongwei Group Co. Ltd, Chengdu, Chengdu, China
| | - Yang-Juan Zhao
- College of Life Sciences, Sichuan Agricultural University, Ya'an, China
| | - Nan Wu
- College of Life Sciences, Sichuan Agricultural University, Ya'an, China
| | - Yang-Er Chen
- College of Life Sciences, Sichuan Agricultural University, Ya'an, China
| | - Wei-Jia Zhang
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, China
| | - Dai-Rong Qiao
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, China
| | - Yi Cao
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, China.
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Li X, Peng W, Jia Y, Lu L, Fan W. Removal of cadmium and zinc from contaminated wastewater using Rhodobacter sphaeroides. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2017; 75:2489-2498. [PMID: 28617267 DOI: 10.2166/wst.2016.608] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Rhodobacter sphaeroides was used for bioremediation of wastewater polluted with cadmium (Cd) and zinc (Zn). The tolerance of the microorganism to selected heavy metals (HMs), as well as the effects of pH, temperature and inoculum size on the removal rate, was investigated. The remediation effects of R. sphaeroides were analysed at different initial concentrations of HMs. Bioremediation mechanisms were thoroughly discussed based on the results from the cell characterisation analysis. Cd and Zn could inhibit the growth of R. sphaeroides. However, Cd was more toxic than Zn, with corresponding EC50 values of 5.34 and 69.79 mg L-1. Temperature and pH had greater influence on the removal rate of HMs than inoculum size. The optimal conditions for temperature and pH were 35 °C-40 °C and pH 7, respectively. Initial concentration of HMs and remediation time also affected the removal rate. Rhodobacter sphaeroides had a relatively higher remediation effect under the present experimental conditions. The removal rates for Cd and Zn reached 97.92% and 97.76%, respectively. Results showed that biosorption and HM precipitation were the main bioremediation mechanisms. This information is necessary to better understand the removal mechanism of R. sphaeroides, and is significant for its pilot test and future practical application.
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Affiliation(s)
- Xiaomin Li
- School of Space and Environment, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing 100191, China E-mail:
| | - Weihua Peng
- School of Space and Environment, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing 100191, China E-mail:
| | - Yingying Jia
- School of Space and Environment, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing 100191, China E-mail:
| | - Lin Lu
- School of Space and Environment, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing 100191, China E-mail:
| | - Wenhong Fan
- School of Space and Environment, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing 100191, China E-mail:
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Kis M, Sipka G, Maróti P. Stoichiometry and kinetics of mercury uptake by photosynthetic bacteria. PHOTOSYNTHESIS RESEARCH 2017; 132:197-209. [PMID: 28260133 DOI: 10.1007/s11120-017-0357-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 02/13/2017] [Indexed: 05/27/2023]
Abstract
Mercury adsorption on the cell surface and intracellular uptake by bacteria represent the key first step in the production and accumulation of highly toxic mercury in living organisms. In this work, the biophysical characteristics of mercury bioaccumulation are studied in intact cells of photosynthetic bacteria by use of analytical (dithizone) assay and physiological photosynthetic markers (pigment content, fluorescence induction, and membrane potential) to determine the amount of mercury ions bound to the cell surface and taken up by the cell. It is shown that the Hg(II) uptake mechanism (1) has two kinetically distinguishable components, (2) includes co-opted influx through heavy metal transporters since the slow component is inhibited by Ca2+ channel blockers, (3) shows complex pH dependence demonstrating the competition of ligand binding of Hg(II) ions with H+ ions (low pH) and high tendency of complex formation of Hg(II) with hydroxyl ions (high pH), and (4) is not a passive but an energy-dependent process as evidenced by light activation and inhibition by protonophore. Photosynthetic bacteria can accumulate Hg(II) in amounts much (about 105) greater than their own masses by well-defined strong and weak binding sites with equilibrium binding constants in the range of 1 (μM)-1 and 1 (mM)-1, respectively. The strong binding sites are attributed to sulfhydryl groups as the uptake is blocked by use of sulfhydryl modifying agents and their number is much (two orders of magnitude) smaller than the number of weak binding sites. Biofilms developed by some bacteria (e.g., Rvx. gelatinosus) increase the mercury binding capacity further by a factor of about five. Photosynthetic bacteria in the light act as a sponge of Hg(II) and can be potentially used for biomonitoring and bioremediation of mercury-contaminated aqueous cultures.
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Affiliation(s)
- Mariann Kis
- Institute of Medical Physics, University of Szeged, Rerrich Béla tér 1, Szeged, 6720, Hungary
| | - Gábor Sipka
- Institute of Medical Physics, University of Szeged, Rerrich Béla tér 1, Szeged, 6720, Hungary
| | - Péter Maróti
- Institute of Medical Physics, University of Szeged, Rerrich Béla tér 1, Szeged, 6720, Hungary.
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Chen Z, Song S, Wen Y. Reduction of Cr (VI) into Cr (III) by organelles of Chlorella vulgaris in aqueous solution: An organelle-level attempt. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 572:361-368. [PMID: 27509074 DOI: 10.1016/j.scitotenv.2016.07.217] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 07/21/2016] [Accepted: 07/30/2016] [Indexed: 05/02/2023]
Abstract
The priority pollutant chromium (Cr) was ubiquitous and great efforts have been made to reduce Cr (VI) into less-toxic Cr (III) by alga for the convenient availability and low expense. However, the functional role of organelle inside the algal cell in Cr (VI) reduction was poorly understood. In this study, organelles in green algae Chlorella vulgaris were extracted and further decorated for Cr (VI) reduction tests. Results showed that the chloroplast exhibited not only adsorption ability of total Cr (21.18% comparing to control) but also reduction potential of Cr (VI) (almost 70% comparing to control), whose most suitable working concentration was at 17μg/mL. Furtherly, the isolated thylakoid membrane (ITM) showed better Cr (VI) reduction potential with the presence of sodium alginate (SA), even though the Hill reaction activity (HRA) was inhibited. As for photosystem II (PSII), the addition of mesoporous silica SBA-15 enhanced the reduction ability through improving the light-harvesting complex (LHC) II efficiency and electron transport rate. On the whole, the reduction ability order of the three kinds of materials based on chloroplast in C. vulgaris was PSII@SBA-15>Chloroplast>ITM@SA. The attempt made in this study to reduce the Cr (VI) with C. vulgaris organelles might not only offer basement to detect the potential action mechanism of Cr (VI) reduction by C. vulgaris but also provide a new sight for the scavenge of heavy metal with biological materials.
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Affiliation(s)
- Zunwei Chen
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Shufang Song
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yuezhong Wen
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
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Li X, Peng W, Jia Y, Lu L, Fan W. Bioremediation of lead contaminated soil with Rhodobacter sphaeroides. CHEMOSPHERE 2016; 156:228-235. [PMID: 27179240 DOI: 10.1016/j.chemosphere.2016.04.098] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 04/13/2016] [Accepted: 04/24/2016] [Indexed: 05/17/2023]
Abstract
Bioremediation with microorganisms is a promising technique for heavy metal contaminated soil. Rhodobacter sphaeroides was previously isolated from oil field injection water and used for bioremediation of lead (Pb) contaminated soil in the present study. Based on the investigation of the optimum culturing conditions and the tolerance to Pb, we employed the microorganism for the remediation of Pb contaminated soil simulated at different contamination levels. It was found that the optimum temperature, pH, and inoculum size for R. sphaeroides is 30-35 °C, 7, and 2 × 10(8) mL(-1), respectively. Rhodobacter sphaeroides did not remove the Pb from soil but did change its speciation. During the bioremediation process, more available fractions were transformed to less accessible and inert fractions; in particular, the exchangeable phase was dramatically decreased while the residual phase was substantially increased. A wheat seedling growing experiment showed that Pb phytoavailability was reduced in amended soils. Results inferred that the main mechanism by which R. sphaeroides treats Pb contaminated soil is the precipitation formation of inert compounds, including lead sulfate and lead sulfide. Although the Pb bioremediation efficiency on wheat was not very high (14.78% root and 24.01% in leaf), R. sphaeroides remains a promising alternative for Pb remediation in contaminated soil.
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Affiliation(s)
- Xiaomin Li
- School of Space and Environment, Beihang University, 37 Xueyuan Road, Haidian District, Beijing 100191, PR China
| | - Weihua Peng
- School of Space and Environment, Beihang University, 37 Xueyuan Road, Haidian District, Beijing 100191, PR China
| | - Yingying Jia
- School of Space and Environment, Beihang University, 37 Xueyuan Road, Haidian District, Beijing 100191, PR China
| | - Lin Lu
- School of Space and Environment, Beihang University, 37 Xueyuan Road, Haidian District, Beijing 100191, PR China
| | - Wenhong Fan
- School of Space and Environment, Beihang University, 37 Xueyuan Road, Haidian District, Beijing 100191, PR China.
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Kis M, Sipka G, Asztalos E, Rázga Z, Maróti P. Purple non-sulfur photosynthetic bacteria monitor environmental stresses. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 151:110-7. [PMID: 26232748 DOI: 10.1016/j.jphotobiol.2015.07.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 07/21/2015] [Accepted: 07/23/2015] [Indexed: 11/19/2022]
Abstract
Heavy metal ion pollution and oxygen deficiency are major environmental risks for microorganisms in aqueous habitat. The potential of purple non-sulfur photosynthetic bacteria for biomonitoring and bioremediation was assessed by investigating the photosynthetic capacity in heavy metal contaminated environments. Cultures of bacterial strains Rhodobacter sphaeroides, Rhodospirillum rubrum and Rubrivivax gelatinosus were treated with heavy metal ions in micromolar (Hg(2+)), submillimolar (Cr(6+)) and millimolar (Pb(2+)) concentration ranges. Functional assays (flash-induced absorption changes and bacteriochlorophyll fluorescence induction) and electron micrographs were taken to specify the harmful effects of pollution and to correlate to morphological changes of the membrane. The bacterial strains and functional tests showed differentiated responses to environmental stresses, revealing that diverse mechanisms of tolerance and/or resistance are involved. The microorganisms were vulnerable to the prompt effect of Pb(2+), showed weak tolerance to Hg(2+) and proved to be tolerant to Cr(6+). The reaction center controlled electron transfer in Rvx. gelatinosus demonstrated the highest degree of resistance against heavy metal exposure.
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Affiliation(s)
- Mariann Kis
- Department of Medical Physics, University of Szeged, Hungary
| | - Gábor Sipka
- Department of Medical Physics, University of Szeged, Hungary
| | - Emese Asztalos
- Department of Medical Physics, University of Szeged, Hungary
| | - Zsolt Rázga
- Department of Pathology, University of Szeged, Hungary
| | - Péter Maróti
- Department of Medical Physics, University of Szeged, Hungary.
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Granafei S, Losito I, Salivo S, Tranchida PQ, Mondello L, Palmisano F, Cataldi TR. Occurrence of oleic and 18:1 methyl-branched acyl chains in lipids of Rhodobacter sphaeroides 2.4.1. Anal Chim Acta 2015; 885:191-8. [DOI: 10.1016/j.aca.2015.05.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 05/11/2015] [Accepted: 05/16/2015] [Indexed: 10/23/2022]
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Mukkata K, Kantachote D, Wittayaweerasak B, Techkarnjanaruk S, Boonapatcharoen N. Diversity of purple nonsulfur bacteria in shrimp ponds with varying mercury levels. Saudi J Biol Sci 2015; 23:478-87. [PMID: 27298580 PMCID: PMC4890186 DOI: 10.1016/j.sjbs.2015.05.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Revised: 05/22/2015] [Accepted: 05/25/2015] [Indexed: 11/20/2022] Open
Abstract
This research aimed to study the diversity of purple nonsulfur bacteria (PNSB) and to investigate the effect of Hg concentrations in shrimp ponds on PNSB diversity. Amplification of the pufM gene was detected in 13 and 10 samples of water and sediment collected from 16 shrimp ponds in Southern Thailand. In addition to PNSB, other anoxygenic phototrophic bacteria (APB) were also observed; purple sulfur bacteria (PSB) and aerobic anoxygenic phototrophic bacteria (AAPB) although most of them could not be identified. Among identified groups; AAPB, PSB and PNSB in the samples of water and sediment were 25.71, 11.43 and 8.57%; and 27.78, 11.11 and 22.22%, respectively. In both sample types, Roseobacter denitrificans (AAPB) was the most dominant species followed by Halorhodospira halophila (PSB). In addition two genera, observed most frequently in the sediment samples were a group of PNSB (Rhodovulum kholense, Rhodospirillum centenum and Rhodobium marinum). The UPGMA dendrograms showed 7 and 6 clustered groups in the water and sediment samples, respectively. There was no relationship between the clustered groups and the total Hg (HgT) concentrations in the water and sediment samples used (<0.002–0.03 μg/L and 35.40–391.60 μg/kg dry weight) for studying the biodiversity. It can be concluded that there was no effect of the various Hg levels on the diversity of detected APB species; particularly the PNSB in the shrimp ponds.
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Affiliation(s)
- Kanokwan Mukkata
- Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai 90112, Thailand
| | - Duangporn Kantachote
- Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai 90112, Thailand; Center of Excellence on Hazardous Substance Management (HSM), Bangkok 10330, Thailand
| | - Banjong Wittayaweerasak
- Center of Excellence on Hazardous Substance Management (HSM), Bangkok 10330, Thailand; Faculty of Environmental Management, Prince of Songkla University, Hat Yai 90112, Thailand
| | - Somkiet Techkarnjanaruk
- National Center for Genetics Engineering and Biotechnology, Bangkok, Thailand; Excellent Center of Waste Utilization and Management, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand
| | - Nimaradee Boonapatcharoen
- Excellent Center of Waste Utilization and Management, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand
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Analyzing the revolution of anaerobic ammonium oxidation (anammox) performance and sludge characteristics under zinc inhibition. Appl Microbiol Biotechnol 2014; 99:3221-32. [DOI: 10.1007/s00253-014-6205-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 10/28/2014] [Accepted: 10/30/2014] [Indexed: 10/24/2022]
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Wu P, Li JZ, Wang YL, Liu XS, Du C, Tong QY, Li N. Promoting the growth of Rubrivivax gelatinosus in sewage purification by the addition of magnesium ions. Biochem Eng J 2014. [DOI: 10.1016/j.bej.2014.07.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Wu P, Li JZ, Wang YL, Tong QY, Liu XS, Du C, Li N. Improving the growth of Rubrivivax gelatinosus cultivated in sewage environment. Bioprocess Biosyst Eng 2014; 38:79-84. [DOI: 10.1007/s00449-014-1245-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Accepted: 06/17/2014] [Indexed: 10/25/2022]
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Modulation of medium pH by Caulobacter crescentus facilitates recovery from uranium-induced growth arrest. Appl Environ Microbiol 2014; 80:5680-8. [PMID: 25002429 DOI: 10.1128/aem.01294-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The oxidized form of uranium [U(VI)] predominates in oxic environments and poses a major threat to ecosystems. Due to its ability to mineralize U(VI), the oligotroph Caulobacter crescentus is an attractive candidate for U(VI) bioremediation. However, the physiological basis for U(VI) tolerance is unclear. Here we demonstrated that U(VI) caused a temporary growth arrest in C. crescentus and three other bacterial species, although the duration of growth arrest was significantly shorter for C. crescentus. During the majority of the growth arrest period, cell morphology was unaltered and DNA replication initiation was inhibited. However, during the transition from growth arrest to exponential phase, cells with shorter stalks were observed, suggesting a decoupling between stalk development and the cell cycle. Upon recovery from growth arrest, C. crescentus proliferated with a growth rate comparable to that of a control without U(VI), although a fraction of these cells appeared filamentous with multiple replication start sites. Normal cell morphology was restored by the end of exponential phase. Cells did not accumulate U(VI) resistance mutations during the prolonged growth arrest, but rather, a reduction in U(VI) toxicity occurred concomitantly with an increase in medium pH. Together, these data suggest that C. crescentus recovers from U(VI)-induced growth arrest by reducing U(VI) toxicity through pH modulation. Our finding represents a unique U(VI) detoxification strategy and provides insight into how microbes cope with U(VI) under nongrowing conditions, a metabolic state that is prevalent in natural environments.
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Li B, Liu N, Li Y, Jing W, Fan J, Li D, Zhang L, Zhang X, Zhang Z, Wang L. Reduction of selenite to red elemental selenium by Rhodopseudomonas palustris strain N. PLoS One 2014; 9:e95955. [PMID: 24759917 PMCID: PMC3997485 DOI: 10.1371/journal.pone.0095955] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 04/01/2014] [Indexed: 02/03/2023] Open
Abstract
The trace metal selenium is in demand for health supplements to human and animal nutrition. We studied the reduction of selenite (SeO₃⁻²) to red elemental selenium by Rhodopseudomonas palustris strain N. This strain was cultured in a medium containing SeO₃⁻² and the particles obtained from cultures were analyzed using transmission electron microscopy (TEM), energy dispersive microanalysis (EDX) and X ray diffraction analysis (XRD). Our results showed the strain N could reduce SeO₃⁻² to red elemental selenium. The diameters of particles were 80-200 nm. The bacteria exhibited significant tolerance to SeO₃⁻² up to 8.0 m mol/L concentration with an EC₅₀ value of 2.4 m mol/L. After 9 d of cultivation, the presence of SeO₃²⁻ up to 1.0 m mol/L resulted in 99.9% reduction of selenite, whereas 82.0% (p<0.05), 31.7% (p<0.05) and 2.4% (p<0.05) reduction of SeO₃⁻² was observed at 2.0, 4.0 and 8.0 m mol/L SeO₃²⁻ concentrations, respectively. This study indicated that red elemental selenium was synthesized by green technology using Rhodopseudomonas palustris strain N. This strain also indicated a high tolerance to SeO₃⁻². The finding of this work will contribute to the application of selenium to human health.
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Affiliation(s)
- Baozhen Li
- School of Life Science, Shanxi University, Taiyuan, China
| | - Na Liu
- School of Life Science, Shanxi University, Taiyuan, China
| | - Yongquan Li
- School of Life Science, Shanxi University, Taiyuan, China
| | - Weixin Jing
- School of Life Science, Shanxi University, Taiyuan, China
| | - Jinhua Fan
- School of Life Science, Shanxi University, Taiyuan, China
| | - Dan Li
- School of Life Science, Shanxi University, Taiyuan, China
| | - Longyan Zhang
- School of Life Science, Shanxi University, Taiyuan, China
| | | | - Zhaoming Zhang
- School of Life Science, Shanxi University, Taiyuan, China
| | - Lan Wang
- School of Life Science, Shanxi University, Taiyuan, China
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41
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Volpicella M, Costanza A, Palumbo O, Italiano F, Claudia L, Placido A, Picardi E, Carella M, Trotta M, Ceci LR. Rhodobacter sphaeroidesadaptation to high concentrations of cobalt ions requires energetic metabolism changes. FEMS Microbiol Ecol 2014; 88:345-57. [DOI: 10.1111/1574-6941.12303] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 02/05/2014] [Accepted: 02/10/2014] [Indexed: 12/01/2022] Open
Affiliation(s)
- Mariateresa Volpicella
- Department of Biosciences, Biotechnologies and Biopharmaceutics; University of Bari; Bari Italy
| | - Alessandra Costanza
- Department of Biosciences, Biotechnologies and Biopharmaceutics; University of Bari; Bari Italy
| | - Orazio Palumbo
- Medical Genetics Unit; IRCCS Casa Sollievo della Sofferenza; San Giovanni Rotondo Italy
| | - Francesca Italiano
- Institute for Chemical-Physical Processes; Italian National Research Council (CNR); Bari Italy
| | - Leoni Claudia
- Department of Biosciences, Biotechnologies and Biopharmaceutics; University of Bari; Bari Italy
- Institute for Biomembranes and Bioenergetics; CNR; Bari Italy
| | - Antonio Placido
- Institute for Biomembranes and Bioenergetics; CNR; Bari Italy
| | - Ernesto Picardi
- Department of Biosciences, Biotechnologies and Biopharmaceutics; University of Bari; Bari Italy
- Institute for Biomembranes and Bioenergetics; CNR; Bari Italy
- National Institute of Biostructures and Biosystems (INBB); Roma Italy
| | - Massimo Carella
- Medical Genetics Unit; IRCCS Casa Sollievo della Sofferenza; San Giovanni Rotondo Italy
| | - Massimo Trotta
- Institute for Chemical-Physical Processes; Italian National Research Council (CNR); Bari Italy
| | - Luigi R. Ceci
- Institute for Biomembranes and Bioenergetics; CNR; Bari Italy
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42
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Grégoire DS, Poulain AJ. A little bit of light goes a long way: the role of phototrophs on mercury cycling. Metallomics 2014; 6:396-407. [DOI: 10.1039/c3mt00312d] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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43
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Calvano CD, Italiano F, Catucci L, Agostiano A, Cataldi TRI, Palmisano F, Trotta M. The lipidome of the photosynthetic bacterium Rhodobacter sphaeroides R26 is affected by cobalt and chromate ions stress. Biometals 2013; 27:65-73. [PMID: 24249151 DOI: 10.1007/s10534-013-9687-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 11/10/2013] [Indexed: 02/07/2023]
Abstract
A detailed characterization of membrane lipids of the photosynthetic bacterium Rhodobacter (R.) sphaeroides was accomplished by thin-layer chromatography coupled with matrix-assisted laser desorption ionization mass spectrometry. Such an approach allowed the identification of the main membrane lipids belonging to different classes, namely cardiolipins (CLs), phosphatidylethanolamines, phosphatidylglycerols (PGs), phosphatidylcholines, and sulfoquinovosyldiacylglycerols (SQDGs). Thus, the lipidomic profile of R. sphaeroides R26 grown in abiotic stressed conditions by exposure to bivalent cobalt cation and chromate oxyanion, was investigated. Compared to bacteria grown under control conditions, significant lipid alterations take place under both stress conditions; cobalt exposure stress results in the relative content increase of CLs and SQDGs, most likely compensating the decrease in PGs content, whereas chromate stress conditions result in the relative content decrease of both PGs and SQDGs, leaving CLs unaltered. For the first time, the response of R. sphaeroides to heavy metals as Co(2+) and CrO4 (2-) is reported and changes in membrane lipid profiles were rationalised.
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Affiliation(s)
- Cosima Damiana Calvano
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via Orabona 4, 70126, Bari, Italy
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44
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Belviso BD, Italiano F, Caliandro R, Carrozzini B, Costanza A, Trotta M. Cobalt binding in the photosynthetic bacterium R. sphaeroides by X-ray absorption spectroscopy. Biometals 2013; 26:693-703. [DOI: 10.1007/s10534-013-9641-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 06/02/2013] [Indexed: 02/06/2023]
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45
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A novel biological approach on extracellular synthesis and characterization of semiconductor zinc sulfide nanoparticles. APPLIED NANOSCIENCE 2012. [DOI: 10.1007/s13204-012-0138-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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46
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Changes in morphology, cell wall composition and soluble proteome in Rhodobacter sphaeroides cells exposed to chromate. Biometals 2012; 25:939-49. [DOI: 10.1007/s10534-012-9561-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 05/17/2012] [Indexed: 11/26/2022]
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47
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Asztalos E, Sipka G, Kis M, Trotta M, Maróti P. The reaction center is the sensitive target of the mercury(II) ion in intact cells of photosynthetic bacteria. PHOTOSYNTHESIS RESEARCH 2012; 112:129-140. [PMID: 22644477 DOI: 10.1007/s11120-012-9749-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 05/14/2012] [Indexed: 06/01/2023]
Abstract
The sensitivity of intact cells of purple photosynthetic bacterium Rhodobacter sphaeroides wild type to low level (<100 μM) of mercury (Hg²⁺) contamination was evaluated by absorption and fluorescence spectroscopies of the bacteriochlorophyll-protein complexes. All assays related to the function of the reaction center (RC) protein (induction of the bacteriochlorophyll fluorescence, delayed fluorescence and light-induced oxidation and reduction of the bacteriochlorophyll dimer and energization of the photosynthetic membrane) showed prompt and later effects of the mercury ions. The damage expressed by decrease of the magnitude and changes of rates of the electron transfer kinetics followed complex (spatial and temporal) pattern according to the different Hg²⁺ sensitivities of the electron transport (donor/acceptor) sites including the reduced bound and free cytochrome c₂ and the primary reduced quinone. In contrast to the RC, the light harvesting system and the bc₁ complex demonstrated much higher resistance against the mercury pollution. The 850 and 875 nm components of the peripheral and core complexes were particularly insensitive to the mercury(II) ions. The concentration of the photoactive RCs and the connectivity of the photosynthetic units decreased upon mercury treatment. The degree of inhibition of the photosynthetic apparatus was always higher when the cells were kept in the light than in the dark indicating the importance of metabolism in active transport of the mercury ions from outside to the intracytoplasmic membrane. Any of the tests applied in this study can be used for detection of changes in photosynthetic bacteria at the early stages of the action of toxicants.
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Affiliation(s)
- Emese Asztalos
- Department of Medical Physics, University of Szeged, Rerrich Béla Tér 1, Szeged 6720, Hungary
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48
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Zheng Q, Meng Q, Wei YY, Yang ZM. Alleviation of copper-induced oxidative damage in Chlamydomonas reinhardtii by carbon monoxide. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2011; 61:220-7. [PMID: 20859622 DOI: 10.1007/s00244-010-9602-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Accepted: 08/30/2010] [Indexed: 05/24/2023]
Abstract
Carbon monoxide (CO) is an endogenous gaseous molecule in plants and animals. Recent studies have shown that it is one of the most essential cellular components regulating many aspects of plant growth and development. However, whether CO regulates the green algae adaptive response to heavy metal toxicity is unknown. The present study investigated the role of CO in regulating Cu-induced oxidative stress in eukaryotic algae Chlamydomonas reinhardtii. Cells pretreated with 5 μM CO for 30 min and followed by exposure to 5 μM Cu(II) for 4 days showed attenuated toxicity. The CO-improved growth of algae was correlated with reduced lipid peroxidation and increased chlorophyll accumulation. The beneficial effect of CO was confirmed by histochemical staining with reactive oxygen species. Further, treatment with 5 μM CO increased the activity of catalase with Cu. However, a reduced superoxide dismutase activity was observed in the CO + Cu-treated algae compared to the control (activity of Cu treatment alone). Under the same condition, the activity of ascorbate peroxidase was not significantly changed. These results suggest that CO can play an important role in regulating the response of algae to Cu stress.
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Affiliation(s)
- Qi Zheng
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, China
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49
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Vílchez R, Gómez-Silván C, Purswani J, González-López J, Rodelas B. Characterization of bacterial communities exposed to Cr(III) and Pb(II) in submerged fixed-bed biofilms for groundwater treatment. ECOTOXICOLOGY (LONDON, ENGLAND) 2011; 20:779-92. [PMID: 21400090 DOI: 10.1007/s10646-011-0629-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/26/2011] [Indexed: 05/13/2023]
Abstract
Two pilot-scale submerged-bed microbial biofilms were set up for the removal of Cr(III) and Pb(II) from groundwater, and the biological activities and structure of the bacterial communities developed in the presence of the heavy metals were analyzed. Artesian groundwater was polluted with Cr(III) or Pb(II) (15 mg/l) and amended with sucrose (250 mg/l) as carbon source. While Pb(II) was over 99% removed from groundwater during long-term operation (130 days), the efficiency of the removal of Cr(III) significantly decreased in time (95-73% after 60 days). Cr(III)-amended biofilms displayed significant lower sucrose consumption, ATP cell contents and alkaline phosphatase activity, compared to biofilms formed in the presence of Pb(II), while analysis of exopolymers demonstrated significant differences in their composition (content of carbohydrates and acetyl groups) in response to each heavy metal. According to transmission electron microscopy (TEM) and electron-dispersive X-ray analysis (EDX), Cr(III) bioaccumulated in the exopolymeric matrix without entering bacterial cells, while Pb(II) was detected both extra and intracellularly, associated to P and Si. Temperature-gradient gel electrophoresis (TGGE) profiling based on partial amplification of 16S rRNA genes was used to analyze the differences in the structure of the biofilm bacterial communities developed under exposure to each heavy metal. Prevalent populations in the biofilms were further identified by reamplification and sequencing of isolated TGGE bands. 75% of the sequences in the Pb(II) biofilter were evolutively close to the Rhodobacterales, while in the Cr(III) biofilter 43% of the sequences were found affiliated to the Rhizobiales and Sphingomonadales, and 57% to Betaproteobacteria.
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Affiliation(s)
- R Vílchez
- Grupo de Microbiología Ambiental (Environmental Microbiology Research Group), Instituto del Agua y Departamento de Microbiología, Facultad de Farmacia, Universidad de Granada, 18071, Granada, Spain
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50
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Italiano F, D’Amici GM, Rinalducci S, De Leo F, Zolla L, Gallerani R, Trotta M, Ceci LR. The photosynthetic membrane proteome of Rhodobacter sphaeroides R-26.1 exposed to cobalt. Res Microbiol 2011; 162:520-7. [DOI: 10.1016/j.resmic.2011.04.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 03/31/2011] [Indexed: 10/18/2022]
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