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Shuwang X, Zhang G, Li D, Wen Y, Zhang G, Sun J. Spatial and temporal changes in the assembly mechanism and co-occurrence network of the chromophytic phytoplankton communities in coastal ecosystems under anthropogenic influences. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 877:162831. [PMID: 36924961 DOI: 10.1016/j.scitotenv.2023.162831] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 02/27/2023] [Accepted: 03/09/2023] [Indexed: 05/06/2023]
Abstract
As a typical semiclosed coastal sea area in China, the ecological environment of Bohai Bay has been significantly disturbed by human activities. As primary producers, the chromophytic phytoplankton are the basis of ecosystems, especially in coastal ecosystems, and changes in the chromophytic phytoplankton community can affect the stability of the entire ecosystem. In this study, we investigated the effects of the human activity-induced spatial and temporal environmental heterogeneity on the community composition, diversity, assembly mechanisms, and co-occurrence networks of chromophytic phytoplankton in Bohai Bay during the wet season and the dry season. The results showed that in both seasons, there was obvious environmental heterogeneity between the nearshore area and the offshore area, and the nearshore areas were more affected by human disturbance. Although higher diversity was supported by the abundance of nutrients in nearshore areas, co-occurrence network analysis revealed that the chromophytic phytoplankton were less closely connected to each other in nearshore areas than in offshore areas due to chemical oxygen demand (COD), eutrophication index (EI), and dissolved inorganic nitrogen (DIN). The nearshore network was less stable than the offshore co-occurrence network in both seasons, which was related to the concentration of dissolved oxygen and COD. Both stochastic and deterministic processes dominated the assembly of the chromophytic phytoplankton communities, with different importance rankings of stochastic and deterministic processes in the nearshore and offshore areas. Drift dominated the assembly of the communities in nearshore areas, while variable selection dominated the assembly of the communities in offshore areas. DIN, EI, and COD, rather than geographic distance, were the main environmental factors affecting the phylogenetic turnover of the chromophytic phytoplankton. Our study showed that environmental heterogeneity caused by human disturbance had a greater impact on the chromophytic phytoplankton communities in Bohai Bay than natural factors such as temperature and salinity.
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Affiliation(s)
- Xinze Shuwang
- Institute for Advanced Marine Research, China University of Geosciences, Guangzhou 511462, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Wuhan 430074, China; College of Fisheries, Ocean University of China, Qingdao 266003, China
| | - Guodong Zhang
- Institute for Advanced Marine Research, China University of Geosciences, Guangzhou 511462, China; Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Danyang Li
- Institute for Advanced Marine Research, China University of Geosciences, Guangzhou 511462, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Wuhan 430074, China; Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Yujian Wen
- Institute for Advanced Marine Research, China University of Geosciences, Guangzhou 511462, China; Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Guicheng Zhang
- Institute for Advanced Marine Research, China University of Geosciences, Guangzhou 511462, China; Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Jun Sun
- Institute for Advanced Marine Research, China University of Geosciences, Guangzhou 511462, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Wuhan 430074, China; Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin 300457, China.
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2
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Li N, Wang B, Huang Y, Huang Q, Jiao F, An S. Response of cbbL-harboring microorganisms to precipitation changes in a naturally-restored grassland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156191. [PMID: 35618124 DOI: 10.1016/j.scitotenv.2022.156191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 05/08/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
The impact of the long-term uneven precipitation distribution model on the diversity and community composition of soil C-fixing microorganisms in arid and semiarid grasslands remains unclear. In 2015, we randomly set up five experimental plots with precipitation gradients on the natural restoration grassland of the Loess Plateau (natural precipitation, NP; ± 40% natural precipitation: decreased precipitation (DP), DP40; increased precipitation (IP), IP40; ± 80% natural precipitation: DP80; IP80). In the third and fifth years after the experimental layout (spanned two years), we explored the cbbL-genes, which are functional genes in the Calvin cycle, harboring microbial diversity and community composition under different precipitation treatments. The results showed that the increase in mean annual precipitation significantly changed the cbbL-harboring microbial alpha diversity, especially when controlling for 40% natural precipitation. The response of the dominant microbial communities to interannual increased precipitation variation shifted from Gammaproteobacteria (Bradyrhizobium) to Betaproteobacteria (Variovorax). The structural equation model showed that precipitation directly affected the cbbL-harboring microbial diversity and community composition and indirectly by affecting soil NO3- (mg N kg -1), soil organic matter, dissolved organic N content, and above- and underground biomass. In conclusion, studying how cbbL-harboring microbial diversity and community composition respond to uneven precipitation variability provides new insights into the ecological processes of C-fixing microbes in semi-arid naturally-restored grasslands dominated by the Calvin cycle.
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Affiliation(s)
- Na Li
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China
| | - Baorong Wang
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resources, Yangling 712100, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yimei Huang
- Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Qian Huang
- Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Feng Jiao
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China.
| | - Shaoshan An
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China; State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resources, Yangling 712100, China.
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3
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Diversity and distribution of CO 2-fixing microbial community along elevation gradients in meadow soils on the Tibetan Plateau. Sci Rep 2022; 12:9621. [PMID: 35688873 PMCID: PMC9187700 DOI: 10.1038/s41598-022-13183-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 05/20/2022] [Indexed: 11/08/2022] Open
Abstract
Soil CO2-fixing microbes play a significant role in CO2-fixation in the terrestrial ecosystems, particularly in the Tibetan Plateau. To understand carbon sequestration by soil CO2-fixing microbes and the carbon cycling in alpine meadow soils, microbial diversity and their driving environmental factors were explored along an elevation gradient from 3900 to 5100 m, on both east and west slopes of Mila Mountain region on the Tibetan Plateau. The CO2-fixing microbial communities were characterized by high-throughput sequencing targeting the cbbL gene, encoding the large subunit for the CO2-fixing protein ribulose 1, 5-bisphosphate carboxylase/oxygenase. The overall OTU (Operational Taxonomic Unit) abundance is concentrated at an altitude between 4300 and 4900 m. The diversity of CO2-fixing microbes is the highest in the middle altitude area, and on the east slope is higher than those on the west slope. In terms of microbial community composition, Proteobacteria is dominant, and the most abundant genera are Cupriavidus, Rhodobacter, Sulfurifustis and Thiobacillus. Altitude has the greatest influence on the structural characteristics of CO2-fixing microbes, and other environmental factors are significantly correlated with altitude. Therefore, altitude influences the structural characteristics of CO2-fixing microbes by driving environmental factors. Our results are helpful to understand the variation in soil microbial community and its role in soil carbon cycling along elevation gradients.
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Chen X, Zhao H, Jiang G, Tang J, Xu Q, Li X, Huang Y, Zou S, Dong K, Hou W, Pan L, Wang P, Huang L, Li N. Trophic states regulate assembly processes and network structures of small chromophytic phytoplankton communities in estuarine and coastal ecosystem. MARINE POLLUTION BULLETIN 2022; 175:113327. [PMID: 35077925 DOI: 10.1016/j.marpolbul.2022.113327] [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: 09/06/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 06/14/2023]
Abstract
Small chromophytic phytoplankton (SCP) are anticipated to be more important for a significant proportion of primary production in estuarine-coastal ecosystems. However, responses of SCP community to coastal eutrophication are still unclear. In this study, we investigated diversity, co-occurrence and assembly features of SCP communities, as well as relationship with environmental factors in subtropical Beibu Gulf. The results exhibited that the alpha diversity and beta diversity of SCP communities were significantly different among eutrophic states. Co-occurrence network revealed a complex interaction that most amplicon sequence variants (ASVs) in modules of the network were specific to trophic states. Further, phylogenetic based β-nearest taxon distance analyses revealed that stochastic processes mainly provided 69.26% contribution to SCP community assembly, whereas deterministic processes dominated community assembly in heavy eutrophic state. Overall, our findings elucidate the mechanism of diversity and assembly in SCP community and promote the understanding of SCP ecology related to subtropical coastal eutrophication.
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Affiliation(s)
- Xing Chen
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education (Nanning Normal University), 175 Mingxiu East Road, Nanning 530001, China; College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Huaxian Zhao
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education (Nanning Normal University), 175 Mingxiu East Road, Nanning 530001, China
| | - Gonglingxia Jiang
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education (Nanning Normal University), 175 Mingxiu East Road, Nanning 530001, China
| | - Jinli Tang
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education (Nanning Normal University), 175 Mingxiu East Road, Nanning 530001, China
| | - Qiangsheng Xu
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education (Nanning Normal University), 175 Mingxiu East Road, Nanning 530001, China
| | - Xiaoli Li
- School of Agriculture, Ludong University, Yantai 264025, China
| | - Yuqing Huang
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education (Nanning Normal University), 175 Mingxiu East Road, Nanning 530001, China
| | - Shuqi Zou
- Department of Biological Sciences, Kyonggi University, 154-42, Gwanggyosan-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16227, South Korea
| | - Ke Dong
- Department of Biological Sciences, Kyonggi University, 154-42, Gwanggyosan-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16227, South Korea
| | - Weiguo Hou
- State Key Laboratory of Biogeosciences and Environmental Geology and Institute of Earth Sciences, China University of Geosciences, Beijing 100083, China
| | - Lianghao Pan
- Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, 92 Changqing Road, Beihai, Guangxi 536000, China
| | - Pengbin Wang
- Fourth Institute of Oceanography, Ministry of Natural Resources, 26 New Century Avenue, Beihai 536000, China; Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, 36 Baochubei Road, Hangzhou 310012, China
| | - Liangliang Huang
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541004, China
| | - Nan Li
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education (Nanning Normal University), 175 Mingxiu East Road, Nanning 530001, China.
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5
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Hoshikawa K, Pham D, Ezura H, Schafleitner R, Nakashima K. Genetic and Molecular Mechanisms Conferring Heat Stress Tolerance in Tomato Plants. FRONTIERS IN PLANT SCIENCE 2021; 12:786688. [PMID: 35003175 PMCID: PMC8739973 DOI: 10.3389/fpls.2021.786688] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/29/2021] [Indexed: 05/17/2023]
Abstract
Climate change is a major threat to global food security. Changes in climate can directly impact food systems by reducing the production and genetic diversity of crops and their wild relatives, thereby restricting future options for breeding improved varieties and reducing the ability to adapt crops to future challenges. The global surface temperature is predicted to rise by an average of 0.3°C during the next decade, and the Paris Agreement (Paris Climate Accords) aims to limit global warming to below an average of 2°C, preferably to 1.5°C compared to pre-industrial levels. Even if the goal of the Paris Agreement can be met, the predicted rise in temperatures will increase the likelihood of extreme weather events, including heatwaves, making heat stress (HS) a major global abiotic stress factor for many crops. HS can have adverse effects on plant morphology, physiology, and biochemistry during all stages of vegetative and reproductive development. In fruiting vegetables, even moderate HS reduces fruit set and yields, and high temperatures may result in poor fruit quality. In this review, we emphasize the effects of abiotic stress, especially at high temperatures, on crop plants, such as tomatoes, touching upon key processes determining plant growth and yield. Specifically, we investigated the molecular mechanisms involved in HS tolerance and the challenges of developing heat-tolerant tomato varieties. Finally, we discuss a strategy for effectively improving the heat tolerance of vegetable crops.
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Affiliation(s)
- Ken Hoshikawa
- Japan International Research Center for Agricultural Sciences, Tsukuba, Japan
- Tsukuba Plant Innovation Research Center, University of Tsukuba, Tsukuba, Japan
- Vegetable Diversity and Improvement, World Vegetable Center, Tainan, Taiwan
| | - Dung Pham
- Faculty of Biotechnology, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Hiroshi Ezura
- Tsukuba Plant Innovation Research Center, University of Tsukuba, Tsukuba, Japan
| | | | - Kazuo Nakashima
- Japan International Research Center for Agricultural Sciences, Tsukuba, Japan
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Hussain S, Min Z, Xiuxiu Z, Khan MH, Lifeng L, Hui C. Significance of Fe(II) and environmental factors on carbon-fixing bacterial community in two paddy soils. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 182:109456. [PMID: 31398779 DOI: 10.1016/j.ecoenv.2019.109456] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 07/15/2019] [Accepted: 07/18/2019] [Indexed: 05/20/2023]
Abstract
The seasonal flooding and drainage process affect the paddy soils, the existence of the iron state either Fe(III) or Fe(II) is the main redox system of paddy soil. Its morphological transformation affects the redox nature of paddy soils, which also affects the distribution of bacterial community diversity. This study based on molecular biological methods (qPCR, Illumina MiSeq sequencing technique) to investigate the effect of Fe(II) and environmental factors on cbbM genes containing carbon fixing microbes. Both Eh5 and pH were reduced with Fe(II) concentrations. The Fe(II) addition significantly affects the cbbM gene copy number in both texture soils. In loamy soil, cbbM gene copy number increased with high addition of Fe(II), while both low and high concentrations significantly reduced the cbbM gene copy number in sandy soil. Chemotrophic bacterial abundance significantly increased by 79.7% and 54.8% with high and low Fe(II) addition in loamy soil while in sandy soil its abundance decreased by 53% and 54% with the low and high Fe(II) accumulation. The phototrophic microbial community increased by 37.8% with low Fe(II) concentration and decreased by 16.2% with a high concentration in loamy soil, while in sandy soil increased by 21% and 14.3% in sandy soil with low and high Fe(II) addition. Chemoheterotrophic carbon fixing bacterial abundance decreased with the Fe(II) accumulation in both soil textures in loamy soil its abundance decreased by 5.8% and 24.8%, while in sand soil 15.7% and 12.8% with low and high Fe(II) concentrations. The Fe(II) concentration and soil textures maybe two of the major factors to shape the bacterial community structure in paddy soils. These results provide a scientific basis for management of paddy soil fertility and it can be beneficial to take measures to ease the greenhouse gases effect.
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Affiliation(s)
- Sarfraz Hussain
- College of Life Sciences/Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhang Min
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhu Xiuxiu
- College of Life Sciences/Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Muzammil Hassan Khan
- College of Life Sciences/Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Li Lifeng
- College of Life Sciences/Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Cao Hui
- College of Life Sciences/Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China.
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7
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Pujari L, Wu C, Kan J, Li N, Wang X, Zhang G, Shang X, Wang M, Zhou C, Sun J. Diversity and Spatial Distribution of Chromophytic Phytoplankton in the Bay of Bengal Revealed by RuBisCO Genes ( rbcL). Front Microbiol 2019; 10:1501. [PMID: 31333613 PMCID: PMC6624743 DOI: 10.3389/fmicb.2019.01501] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 06/14/2019] [Indexed: 11/13/2022] Open
Abstract
Phytoplankton are the basis of primary production and play important roles in regulating energy export in marine ecosystems. Compared to other regions, chromophytic phytoplankton are considerably understudied in the Bay of Bengal (BOB). Here, we investigated community structure and spatial distribution of chromophytic phytoplankton in the BOB by using RuBisCO genes (Form ID rbcL). High throughput sequencing of rbcL genes revealed that diatoms, cyanobacteria (Cyanophyceae), Pelagophyceae, Haptophyceae, Chrysophyceae, Eustigamatophyceae, Xanthophyceae, Cryptophyceae, Dictyochophyceae, and Pinguiophyceae were the most abundant groups recovered in the BOB. Abundances and distribution of diatoms and Pelagophyceae were further verified using quantitative PCR analyses which showed the dominance of these groups near the Equator region (p < 0.01) where upwelling was likely the source of nutrients. Further, redundancy analysis demonstrated that temperature was an important environmental driver in structuring distributions of Cyanophyceae and dominant chromophytic phytoplankton. Morphological identification and quantification confirmed the dominance of diatoms, and also detected other cyanobacteria and dinoflagellates that were missing in our molecular characterizations. Pearson’s correlations of these morphologically identified phytoplankton with environmental gradients also indicated that nutrients and temperature were key variables shaping community structure. Combination of molecular characterization and morphological identification provided a comprehensive overview of chromophytic phytoplankton. This is the first molecular study of chromophytic phytoplankton accomplished in the BOB, and our results highlight a combination of molecular analysis targeting rbcL genes and microscopic detection in examining phytoplankton composition and diversity.
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Affiliation(s)
- Laxman Pujari
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China.,Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, China
| | - Chao Wu
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China.,Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Jinjun Kan
- Stroud Water Research Center, Avondale, PA, United States
| | - Nan Li
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Nanning Normal University, Nanning, China
| | - Xingzhou Wang
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China.,Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, China
| | - Guicheng Zhang
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China.,Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, China
| | - Xiaomei Shang
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China.,Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, China
| | - Min Wang
- College of Marine Life Science, Ocean University of China, Qingdao, China
| | - Chun Zhou
- Key Laboratory of Physical Oceanography/CIMST, Ocean University of China, Qingdao, China
| | - Jun Sun
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China.,Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, China
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8
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Maheshwari N, Kumar M, Thakur IS, Srivastava S. Carbon dioxide biofixation by free air CO2 enriched (FACE) bacterium for biodiesel production. J CO2 UTIL 2018. [DOI: 10.1016/j.jcou.2018.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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9
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Alfreider A, Baumer A, Bogensperger T, Posch T, Salcher MM, Summerer M. CO 2 assimilation strategies in stratified lakes: Diversity and distribution patterns of chemolithoautotrophs. Environ Microbiol 2017; 19:2754-2768. [PMID: 28474482 PMCID: PMC5619642 DOI: 10.1111/1462-2920.13786] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 04/18/2017] [Accepted: 04/21/2017] [Indexed: 11/23/2022]
Abstract
While mechanisms of different carbon dioxide (CO2) assimilation pathways in chemolithoautotrohic prokaryotes are well understood for many isolates under laboratory conditions, the ecological significance of diverse CO2 fixation strategies in the environment is mostly unexplored. Six stratified freshwater lakes were chosen to study the distribution and diversity of the Calvin-Benson-Bassham (CBB) cycle, the reductive tricarboxylic acid (rTCA) cycle, and the recently discovered archaeal 3-hydroxypropionate/4-hydroxybutyrate (HP/HB) pathway. Eleven primer sets were used to amplify and sequence genes coding for selected key enzymes in the three pathways. Whereas the CBB pathway with different forms of RubisCO (IA, IC and II) was ubiquitous and related to diverse bacterial taxa, encompassing a wide range of potential physiologies, the rTCA cycle in Epsilonproteobacteria and Chloribi was exclusively detected in anoxic water layers. Nitrifiying Nitrosospira and Thaumarchaeota, using the rTCA and HP/HB cycle respectively, are important residents in the aphotic and (micro-)oxic zone of deep lakes. Both taxa were of minor importance in surface waters and in smaller lakes characterized by an anoxic hypolimnion. Overall, this study provides a first insight on how different CO2 fixation strategies and chemical gradients in lakes are associated to the distribution of chemoautotrophic prokaryotes with different functional traits.
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Affiliation(s)
- Albin Alfreider
- Institute for Ecology, University of Innsbruck, Innsbruck, Austria
| | - Andreas Baumer
- Institute for Ecology, University of Innsbruck, Innsbruck, Austria
| | | | - Thomas Posch
- Limnological Station, Department of Plant and Microbial Biology, University of Zurich, Kilchberg, Switzerland
| | - Michaela M Salcher
- Limnological Station, Department of Plant and Microbial Biology, University of Zurich, Kilchberg, Switzerland.,Institute of Hydrobiology, Biology Centre CAS, České Budějovice, Czech Republic
| | - Monika Summerer
- Institute for Ecology, University of Innsbruck, Innsbruck, Austria
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10
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Yuan H, Ge T, Chen X, Liu S, Zhu Z, Wu X, Wei W, Whiteley AS, Wu J. Abundance and Diversity of CO2-Assimilating Bacteria and Algae Within Red Agricultural Soils Are Modulated by Changing Management Practice. MICROBIAL ECOLOGY 2015; 70:971-980. [PMID: 25956939 DOI: 10.1007/s00248-015-0621-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 04/23/2015] [Indexed: 06/04/2023]
Abstract
Elucidating the biodiversity of CO(2)-assimilating bacterial and algal communities in soils is important for obtaining a mechanistic view of terrestrial carbon sinks operating at global scales. "Red" acidic soils (Orthic Acrisols) cover large geographic areas and are subject to a range of management practices, which may alter the balance between carbon dioxide production and assimilation through changes in microbial CO(2)-assimilating populations. Here, we determined the abundance and diversity of CO(2)-assimilating bacteria and algae in acidic soils using quantitative PCR and terminal restriction fragment length polymorphism (T-RFLP) of the cbbL gene, which encodes the key CO(2) assimilation enzyme (ribulose-1,5-bisphosphate carboxylase/oxygenase) in the Calvin cycle. Within the framework of a long-term experiment (Taoyuan Agro-ecosystem, subtropical China), paddy rice fields were converted in 1995 to four alternative land management regimes: natural forest (NF), paddy rice (PR), maize crops (CL), and tea plantations (TP). In 2012 (17 years after land use transformation), we collected and analyzed the soils from fields under the original and converted land management regimes. Our results indicated that fields under the PR soil management system harbored the greatest abundance of cbbL copies (4.33 × 10(8) copies g(-1) soil). More than a decade after converting PR soils to natural, rotation, and perennial management systems, a decline in both the diversity and abundance of cbbL-harboring bacteria and algae was recorded. The lowest abundance of bacteria (0.98 × 10(8) copies g(-1) soil) and algae (0.23 × 10(6) copies g(-1) soil) was observed for TP soils. When converting PR soil management to alternative management systems (i.e., NF, CL, and TP), soil edaphic factors (soil organic carbon and total nitrogen content) were the major determinants of bacterial autotrophic cbbL gene diversity. In contrast, soil phosphorus concentration was the major regulator of algal cbbL community composition. Our results provide new insights into the diversity, abundance, and modulation of organisms responsible for microbial autotrophic CO(2) fixation in red acidic soils subjected to changing management regimes.
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Affiliation(s)
- Hongzhao Yuan
- Changsha Research Station for Agricultural and Environmental Monitoring & Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, China
- ISA-CAS and UWA Joint Laboratory for Soil Systems Biology, Hunan, 410125, China
| | - Tida Ge
- Changsha Research Station for Agricultural and Environmental Monitoring & Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, China.
- ISA-CAS and UWA Joint Laboratory for Soil Systems Biology, Hunan, 410125, China.
| | - Xiangbi Chen
- Changsha Research Station for Agricultural and Environmental Monitoring & Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, China
| | - Shoulong Liu
- Changsha Research Station for Agricultural and Environmental Monitoring & Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, China
| | - Zhenke Zhu
- Changsha Research Station for Agricultural and Environmental Monitoring & Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, China
- ISA-CAS and UWA Joint Laboratory for Soil Systems Biology, Hunan, 410125, China
| | - Xiaohong Wu
- Changsha Research Station for Agricultural and Environmental Monitoring & Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, China
- ISA-CAS and UWA Joint Laboratory for Soil Systems Biology, Hunan, 410125, China
| | - Wenxue Wei
- Changsha Research Station for Agricultural and Environmental Monitoring & Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, China
- Taoyuan Agro-ecosystem Research Station, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
| | - Andrew Steven Whiteley
- ISA-CAS and UWA Joint Laboratory for Soil Systems Biology, Hunan, 410125, China
- School of Earth & Environment, The University of Western Australia, Crawley, Perth, WA, 6009, Australia
| | - Jinshui Wu
- Changsha Research Station for Agricultural and Environmental Monitoring & Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, China
- ISA-CAS and UWA Joint Laboratory for Soil Systems Biology, Hunan, 410125, China
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11
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Rodriguez-Mora MJ, Scranton MI, Taylor GT, Chistoserdov AY. The dynamics of the bacterial diversity in the redox transition and anoxic zones of the Cariaco Basin assessed by parallel tag sequencing. FEMS Microbiol Ecol 2015. [PMID: 26209697 DOI: 10.1093/femsec/fiv088] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Massively parallel tag sequencing was applied to describe the bacterial diversity in the redox transition and anoxic zones of the Cariaco Basin. In total, 14 samples from the Cariaco Basin were collected over a period of eight years from two stations. A total of 244 357 unique bacterial V6 amplicons were sequenced. The total number of operational taxonomic units (OTUs) found in this study was 4692, with a range of 511-1491 OTUs per sample. Approximately 95% of the OTUs found in the redox transition zone and anoxic layers of Cariaco are represented by less than 50 amplicons suggesting that only about 5% of the bacterial OTUs are responsible for the bulk of the microbial processes in the basin redox transition and anoxic zones. The same dominant OTUs were observed across all eight years of sampling although periodic fluctuations in their proportion were apparent. No distinctive differences were observed between the bacterial communities from the redox transition and anoxic layers of the Cariaco Basin water column. The largest proportion of amplicons belongs to Gammaproteobacteria represented mostly by sulfide oxidizers, followed by Marine Group A (originally described as SAR406; Gordon and Giovannoni 1996), a group of uncultured bacteria hypothesized to be involved in metal reduction, and sulfate-reducing Deltaproteobacteria. Gammaproteobacteria, Deltaproteobacteria and Marine Group A make up 67-90% of all V6 amplicons sequenced in this study. This strongly suggests that the basin's microbial communities are actively involved in the sulfur-related metabolism and coupling of the sulfur and carbon cycles. According to detrended canonical correspondence analysis, ecological factors such as chemoautotrophy, nitrate and oxidized and reduced sulfur compounds influence the structuring and distribution of the Cariaco microbial communities.
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Affiliation(s)
| | - Mary I Scranton
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Gordon T Taylor
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Andrei Y Chistoserdov
- Department of Biology, University of Louisiana at Lafayette, Lafayette, LA 70504, USA
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Guo G, Kong W, Liu J, Zhao J, Du H, Zhang X, Xia P. Diversity and distribution of autotrophic microbial community along environmental gradients in grassland soils on the Tibetan Plateau. Appl Microbiol Biotechnol 2015; 99:8765-76. [PMID: 26084890 DOI: 10.1007/s00253-015-6723-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 05/19/2015] [Accepted: 05/23/2015] [Indexed: 10/23/2022]
Abstract
Soil microbial autotrophs play a significant role in CO2 fixation in terrestrial ecosystem, particularly in vegetation-constrained ecosystems with environmental stresses, such as the Tibetan Plateau characterized by low temperature and high UV. However, soil microbial autotrophic communities and their driving factors remain less appreciated. We investigated the structure and shift of microbial autotrophic communities and their driving factors along an elevation gradient (4400-5100 m above sea level) in alpine grassland soils on the Tibetan Plateau. The autotrophic microbial communities were characterized by quantitative PCR, terminal restriction fragment length polymorphism (T-RFLP), and cloning/sequencing of cbbL genes, encoding the large subunit for the CO2 fixation protein ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO). High cbbL gene abundance and high RubisCO enzyme activity were observed and both significantly increased with increasing elevations. Path analysis identified that soil RubisCO enzyme causally originated from microbial autotrophs, and its activity was indirectly driven by soil water content, temperature, and NH4 (+) content. Soil autotrophic microbial community structure dramatically shifted along the elevation and was jointly driven by soil temperature, water content, nutrients, and plant types. The autotrophic microbial communities were dominated by bacterial autotrophs, which were affiliated with Rhizobiales, Burkholderiales, and Actinomycetales. These autotrophs have been well documented to degrade organic matters; thus, metabolic versatility could be a key strategy for microbial autotrophs to survive in the harsh environments. Our results demonstrated high abundance of microbial autotrophs and high CO2 fixation potential in alpine grassland soils and provided a novel model to identify dominant drivers of soil microbial communities and their ecological functions.
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Affiliation(s)
- Guangxia Guo
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Weidong Kong
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Jinbo Liu
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jingxue Zhao
- Key Laboratory of Tibetan Environmental Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Haodong Du
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xianzhou Zhang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Pinhua Xia
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China.,Guizhou Key Laboratory for Mountainous Environmental Information and Ecological Protection, Guizhou Normal University, Guiyang, 550001, China
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13
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Mayfield AB, Hsiao YY, Chen HK, Chen CS. Rubisco expression in the dinoflagellate Symbiodinium sp. is influenced by both photoperiod and endosymbiotic lifestyle. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2014; 16:371-384. [PMID: 24449387 DOI: 10.1007/s10126-014-9558-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 10/10/2013] [Indexed: 06/03/2023]
Abstract
Although the importance of anthozoan-dinoflagellate (genus Symbiodinium) endosymbioses in the establishment of coral reef ecosystems is evident, little is known about the molecular regulation of photosynthesis in the intra-gastrodermal symbiont communities, particularly with respect to the rate-limiting Calvin cycle enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco). In this study, we analyzed rubisco mRNA (rbcL) and protein (RBCL) concentrations over the diel cycle in both cultured and endosymbiotic Symbiodinium samples. In the former, rbcL expression increased upon illumination and decreased during the dark, a pattern that was upheld under continual dark incubation. A different trend in rbcL expression was observed in endosymbiotic Symbiodinium residing within sea anemone (Aiptasia pulchella) tissues, in which illumination gradually led to decreased rbcL mRNA expression. Unexpectedly, RBCL protein expression did not vary over time within anemone tissues, and in neither cultured nor endosymbiotic samples was a correlation between gene and protein expression documented. It appears, then, that photoperiod, lifestyle, and posttranscriptional regulation are all important drivers of RBCL expression in this ecologically important dinoflagellate.
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Affiliation(s)
- Anderson B Mayfield
- Taiwan Coral Research Center (TCRC), National Museum of Marine Biology and Aquarium, 2 Houwan Rd., Checheng, Pingtung 944, Taiwan, Republic of China
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Xiao KQ, Bao P, Bao QL, Jia Y, Huang FY, Su JQ, Zhu YG. Quantitative analyses of ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) large-subunit genes (cbbL) in typical paddy soils. FEMS Microbiol Ecol 2013; 87:89-101. [DOI: 10.1111/1574-6941.12193] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 08/12/2013] [Accepted: 08/20/2013] [Indexed: 11/28/2022] Open
Affiliation(s)
- Ke-Qing Xiao
- State Key Laboratory of Urban and Regional Ecology; Research Center for Eco-Environmental Sciences; Chinese Academy of Sciences; Beijing China
- University of Chinese Academy of Sciences; Beijing China
| | - Peng Bao
- State Key Laboratory of Urban and Regional Ecology; Research Center for Eco-Environmental Sciences; Chinese Academy of Sciences; Beijing China
| | - Qiong-Li Bao
- State Key Laboratory of Urban and Regional Ecology; Research Center for Eco-Environmental Sciences; Chinese Academy of Sciences; Beijing China
| | - Yan Jia
- State Key Laboratory of Urban and Regional Ecology; Research Center for Eco-Environmental Sciences; Chinese Academy of Sciences; Beijing China
- University of Chinese Academy of Sciences; Beijing China
| | - Fu-Yi Huang
- University of Chinese Academy of Sciences; Beijing China
- Key Lab of Urban Environment and Health; Institute of Urban Environment; Chinese Academy of Sciences; Xiamen China
| | - Jian-Qiang Su
- Key Lab of Urban Environment and Health; Institute of Urban Environment; Chinese Academy of Sciences; Xiamen China
| | - Yong-Guan Zhu
- State Key Laboratory of Urban and Regional Ecology; Research Center for Eco-Environmental Sciences; Chinese Academy of Sciences; Beijing China
- Key Lab of Urban Environment and Health; Institute of Urban Environment; Chinese Academy of Sciences; Xiamen China
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15
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Recovery of soil unicellular eukaryotes: an efficiency and activity analysis on the single cell level. J Microbiol Methods 2013; 95:463-9. [PMID: 23680233 DOI: 10.1016/j.mimet.2013.05.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 05/02/2013] [Accepted: 05/06/2013] [Indexed: 11/22/2022]
Abstract
Eukaryotic unicellular organisms are an important part of the soil microbial community, but they are often neglected in soil functional microbial diversity analysis, principally due to the absence of specific investigation methods in the special soil environment. In this study we used a method based on high-density centrifugation to specifically isolate intact algal and yeast cells, with the aim to analyze them with flow cytometry and sort them for further molecular analysis such as deep sequencing. Recovery efficiency was tested at low abundance levels that fit those in natural environments (10(4) to 10(6) cells per g soil). Five algae and five yeast morphospecies isolated from soil were used for the testing. Recovery efficiency was between 1.5 to 43.16% and 2 to 30.2%, respectively, and was dependent on soil type for three of the algae. Control treatments without soil showed that the majority of cells were lost due to the method itself (58% and 55.8% respectively). However, the cell extraction technique did not much compromise cell vitality because a fluorescein di-acetate assay indicated high viability percentages (73.3% and 97.2% of cells, respectively). The low abundant algae and yeast morphospecies recovered from soil were cytometrically analyzed and sorted. Following, their DNA was isolated and amplified using specific primers. The developed workflow enables isolation and enrichment of intact autotrophic and heterotrophic soil unicellular eukaryotes from natural environments for subsequent application of deep sequencing technologies.
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Rodriguez-Mora MJ, Scranton MI, Taylor GT, Chistoserdov AY. Bacterial community composition in a large marine anoxic basin: a Cariaco Basin time-series survey. FEMS Microbiol Ecol 2013; 84:625-39. [PMID: 23398056 DOI: 10.1111/1574-6941.12094] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 01/18/2013] [Accepted: 02/05/2013] [Indexed: 11/30/2022] Open
Abstract
Redox transition zones play a crucial role in biogeochemical cycles of several major elements. Because microorganisms mediate many reactions of these cycles, they actively participate in establishing geochemical gradients. In turn, the geochemical gradients structure microbial communities. We studied the interrelationship between the bacterial community structure and the geochemical gradient in the Cariaco Basin, the largest truly marine anoxic basin. This study's dataset includes bacterial community composition in 113 water column samples as well as the data for environmental variables (gradients of oxygen, hydrogen sulfide, sulfite, thiosulfate, ammonia, nitrate, nitrite, dissolved manganese and iron, dark CO2 fixation, and bacterial abundance) collected between 1997 and 2006. Several prominent bacterial groups are present throughout the entire water column. These include members of Gamma-, Delta-, and Epsilonproteobacteria, as well as members of the Marine Group A, the candidate divisions OP11 and Car731c. Canonical correspondence analysis indicated that microbial communities segregate along vectors representing oxygenated conditions, nitrite, nitrate and anoxic environments represented by chemoautotrophy, ammonia, sulfite, and hydrogen sulfide.
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Diversity and expression of RubisCO genes in a perennially ice-covered Antarctic lake during the polar night transition. Appl Environ Microbiol 2012; 78:4358-66. [PMID: 22492447 DOI: 10.1128/aem.00029-12] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The autotrophic communities in the lakes of the McMurdo Dry Valleys, Antarctica, have generated interest since the early 1960s owing to low light transmission through the permanent ice covers, a strongly bimodal seasonal light cycle, constant cold water temperatures, and geographical isolation. Previous work has shown that autotrophic carbon fixation in these lakes provides an important source of organic matter to this polar desert. Lake Bonney has two lobes separated by a shallow sill and is one of several chemically stratified lakes in the dry valleys that support year-round biological activity. As part of an International Polar Year initiative, we monitored the diversity and abundance of major isoforms of RubisCO in Lake Bonney by using a combined sequencing and quantitative PCR approach during the transition from summer to polar winter. Form ID RubisCO genes related to a stramenopile, a haptophyte, and a cryptophyte were identified, while primers specific for form IA/B RubisCO detected a diverse autotrophic community of chlorophytes, cyanobacteria, and chemoautotrophic proteobacteria. Form ID RubisCO dominated phytoplankton communities in both lobes of the lake and closely matched depth profiles for photosynthesis and chlorophyll. Our results indicate a coupling between light availability, photosynthesis, and rbcL mRNA levels in deep phytoplankton populations. Regulatory control of rbcL in phytoplankton living in nutrient-deprived shallow depths does not appear to be solely light dependent. The distinct water chemistries of the east and west lobes have resulted in depth- and lobe-dependent variability in RubisCO diversity, which plays a role in transcriptional activity of the key gene responsible for carbon fixation.
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Long-term field fertilization alters the diversity of autotrophic bacteria based on the ribulose-1,5-biphosphate carboxylase/oxygenase (RubisCO) large-subunit genes in paddy soil. Appl Microbiol Biotechnol 2011; 95:1061-71. [PMID: 22159889 DOI: 10.1007/s00253-011-3760-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 11/12/2011] [Accepted: 11/14/2011] [Indexed: 10/14/2022]
Abstract
Carbon dioxide (CO(2)) assimilation by autotrophic bacteria is an important process in the soil carbon cycle with major environmental implications. The long-term impact of fertilizer on CO(2) assimilation in the bacterial community of paddy soils remains poorly understood. To narrow this knowledge gap, the composition and abundance of CO(2)-assimilating bacteria were investigated using terminal restriction fragment length polymorphism and quantitative PCR of the cbbL gene [that encodes ribulose-1,5-biphosphate carboxylase/oxygenase (RubisCO)] in paddy soils. Soils from three stations in subtropical China were used. Each station is part of a long-term fertilization experiment with three treatments: no fertilizer (CK), chemical fertilizers (NPK), and NPK combined with rice straw (NPKM). At all of the stations, the cbbL-containing bacterial communities were dominated by facultative autotrophic bacteria such as Rhodopseudomonas palustris, Bradyrhizobium japonicum, and Ralstonia eutropha. The community composition in the fertilized soil (NPK and NPKM) was distinct from that in unfertilized soil (CK). The bacterial cbbL abundance (3-8 × 10(8) copies g soil(-1)) and RubisCO activity (0.40-1.76 nmol CO(2) g soil(-1) min(-1)) in paddy soils were significantly positively correlated, and both increased with the addition of fertilizer. Among the measured soil parameters, soil organic carbon and pH were the most significant factors influencing the community composition, abundance, and activity of the cbbL-containing bacteria. These results suggest that long-term fertilization has a strong impact on the activity and community of cbbL-containing bacterial populations in paddy soils, especially when straw is combined with chemical fertilizers.
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El-Bakatoushi R. Identification and characterization of up-regulated genes in the halophyte Limoniastrum monopetalum (L.) Boiss grown under crude oil pollution. JOURNAL OF GENETIC ENGINEERING AND BIOTECHNOLOGY 2011. [DOI: 10.1016/j.jgeb.2011.10.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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20
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Fujimura R, Sato Y, Nishizawa T, Nanba K, Oshima K, Hattori M, Kamijo T, Ohta H. Analysis of early bacterial communities on volcanic deposits on the island of Miyake (Miyake-jima), Japan: a 6-year study at a fixed site. Microbes Environ 2011; 27:19-29. [PMID: 22075623 PMCID: PMC4036035 DOI: 10.1264/jsme2.me11207] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Microbial colonization on new terrestrial substrates represents the initiation of new soil ecosystem formation. In this study, we analyzed early bacterial communities growing on volcanic ash deposits derived from the 2000 Mount Oyama eruption on the island of Miyake (Miyake-jima), Japan. A site was established in an unvegetated area near the summit and investigated over a 6-year period from 2003 to 2009. Collected samples were acidic (pH 3.0–3.6), did not utilize any organic substrates in ECO microplate assays (Biolog), and harbored around 106 cells (g dry weight)−1 of autotrophic Fe(II) oxidizers by most-probable-number (MPN) counts. Acidithiobacillus ferrooxidans, Acidithiobacillus ferrivorans, and the Leptospirillum groups I, II and III were found to be abundant in the deposits by clone library analysis of bacterial 16S rRNA genes. The numerical dominance of Acidithiobacillus ferrooxidans was also supported by analysis of the gene coding for the large subunit of the form I ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO). Comparing the 16S rRNA gene clone libraries from samples differing in age, shifts in Fe(II)-oxidizing populations seemed to occur with deposit aging. The detection of known 16S rRNA gene sequences from Fe(III)-reducing acidophiles promoted us to propose the acidity-driven iron cycle for the early microbial ecosystem on the deposit.
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Affiliation(s)
- Reiko Fujimura
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan
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21
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Meakin NG, Wyman M. Rapid shifts in picoeukaryote community structure in response to ocean acidification. THE ISME JOURNAL 2011; 5:1397-405. [PMID: 21412344 PMCID: PMC3160676 DOI: 10.1038/ismej.2011.18] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Revised: 01/20/2011] [Accepted: 01/22/2011] [Indexed: 11/09/2022]
Abstract
Rapid shifts in picoeukaryote community structure were observed during a CO(2) perturbation experiment in which we followed the development of phytoplankton blooms in nutrient-amended mesocosms under the present day or predicted future atmospheric pCO(2) (750 μatm, seawater pH 7.8). Analysis of rbcL clone libraries (encoding the large subunit of RubisCO) and specific quantitative PCR assays showed that two prasinophytes closely related to Micromonas pusilla and Bathycoccus prasinos were present, but responded very differently to high CO(2)/acidification. We found that the abundance of Micromonas-like phylotypes was significantly higher (>20-fold) under elevated CO(2)/low pH, whereas the Bathycoccus-like phylotypes were more evenly distributed between treatments and dominated the prasinophyte community under ambient conditions.
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Affiliation(s)
- Nicholas G Meakin
- School of Biological and Environmental Sciences, University of Stirling, Stirling, UK
| | - Michael Wyman
- School of Biological and Environmental Sciences, University of Stirling, Stirling, UK
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22
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Functional prokaryotic RubisCO from an oceanic metagenomic library. Appl Environ Microbiol 2010; 76:2997-3003. [PMID: 20228113 DOI: 10.1128/aem.02661-09] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Culture-independent studies have indicated that there is significant diversity in the ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) enzymes used by marine, freshwater, and terrestrial autotrophic bacteria. Surprisingly, little is known about the catalytic properties of many environmentally significant RubisCO enzymes. Because one of the goals of RubisCO research is to somehow modify or select for RubisCO molecules with improved kinetic properties, a facile means to isolate functional and novel RubisCO molecules directly from the environment was developed. In this report, we describe the first example of functional RubisCO proteins obtained from genes cloned and characterized from metagenomic libraries derived from DNA isolated from environmental samples. Two form IA marine RubisCO genes were cloned, and each gene supported both photoheterotrophic and photoautotrophic growth of a RubisCO deletion strain of Rhodobacter capsulatus, strain SBI/II(-), indicating that catalytically active recombinant RubisCO was synthesized. The catalytic properties of the metagenomic RubisCO molecules were further characterized. These experiments demonstrated the feasibility of studying the functional diversity and enzymatic properties of RubisCO enzymes without first cultivating the host organisms. Further, this "proof of concept" experiment opens the way for development of a simple functional screen to examine the properties of diverse RubisCO genes isolated from any environment, and subsequent further bioselection may be possible if the growth conditions of complemented R. capsulatus strain SBI/II(-) are varied.
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Kamimura K, Okabayashi A, Kikumoto M, Manchur MA, Wakai S, Kanao T. Analysis of iron- and sulfur-oxidizing bacteria in a treatment plant of acid rock drainage from a Japanese pyrite mine by use of ribulose-1, 5-bisphosphate carboxylase/oxygenase large-subunit gene. J Biosci Bioeng 2010; 109:244-8. [DOI: 10.1016/j.jbiosc.2009.08.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2009] [Revised: 07/21/2009] [Accepted: 08/12/2009] [Indexed: 11/16/2022]
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Crespo-Medina M, Chatziefthimiou A, Cruz-Matos R, Pérez-Rodríguez I, Barkay T, Lutz RA, Starovoytov V, Vetriani C. Salinisphaera hydrothermalis sp. nov., a mesophilic, halotolerant, facultatively autotrophic, thiosulfate-oxidizing gammaproteobacterium from deep-sea hydrothermal vents, and emended description of the genus Salinisphaera. Int J Syst Evol Microbiol 2009; 59:1497-503. [PMID: 19502342 DOI: 10.1099/ijs.0.005058-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A mesophilic, aerobic, facultatively chemolithoautotrophic bacterium, designated strain EPR70(T), was isolated from hydrothermal fluids from diffuse-flow vents on the East Pacific Rise at degrees 50' N 10 degrees 17' W. Cells were Gram-negative rods, approximately 0.8-1.0 microm long and 0.3-0.5 microm wide. Strain EPR70(T) grew at 20-40 degrees C (optimum 30-35 degrees C), 1-25 % NaCl (optimum 2.5 %) and pH 5.0-7.5 (optimum pH 5.5). The shortest generation time observed for strain EPR70(T) was 42 min. Growth occurred under aerobic chemolithoautotrophic conditions in the presence of thiosulfate and CO(2). Strain EPR70(T) grew heterotrophically with acetate or n-alkanes as sole carbon and energy sources, and in complex artificial seawater medium. Nitrate was not used as an electron acceptor. The G+C content of the genomic DNA was 64 mol%. Phylogenetic analysis of the 16S rRNA gene indicated that this organism is a member of the class Gammaproteobacteria, with Salinisphaera shabanensis E1L3A(T) as its closest relative (94 % sequence similarity). On the basis of phylogenetic analyses based on 16S rRNA, rbcL and alkB genes and physiological analysis, it is proposed that the organism represents a novel species within the genus Salinisphaera, for which the name Salinisphaera hydrothermalis sp. nov. is proposed. The type strain is EPR70(T) (=DSM 21483(T) =JCM 15514(T)).
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Function, structure, and evolution of the RubisCO-like proteins and their RubisCO homologs. Microbiol Mol Biol Rev 2008; 71:576-99. [PMID: 18063718 DOI: 10.1128/mmbr.00015-07] [Citation(s) in RCA: 224] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
About 30 years have now passed since it was discovered that microbes synthesize RubisCO molecules that differ from the typical plant paradigm. RubisCOs of forms I, II, and III catalyze CO(2) fixation reactions, albeit for potentially different physiological purposes, while the RubisCO-like protein (RLP) (form IV RubisCO) has evolved, thus far at least, to catalyze reactions that are important for sulfur metabolism. RubisCO is the major global CO(2) fixation catalyst, and RLP is a somewhat related protein, exemplified by the fact that some of the latter proteins, along with RubisCO, catalyze similar enolization reactions as a part of their respective catalytic mechanisms. RLP in some organisms catalyzes a key reaction of a methionine salvage pathway, while in green sulfur bacteria, RLP plays a role in oxidative thiosulfate metabolism. In many organisms, the function of RLP is unknown. Indeed, there now appear to be at least six different clades of RLP molecules found in nature. Consideration of the many RubisCO (forms I, II, and III) and RLP (form IV) sequences in the database has subsequently led to a coherent picture of how these proteins may have evolved, with a form III RubisCO arising from the Methanomicrobia as the most likely ultimate source of all RubisCO and RLP lineages. In addition, structure-function analyses of RLP and RubisCO have provided information as to how the active sites of these proteins have evolved for their specific functions.
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Tolli J, King GM. Diversity and structure of bacterial chemolithotrophic communities in pine forest and agroecosystem soils. Appl Environ Microbiol 2006; 71:8411-8. [PMID: 16332829 PMCID: PMC1317390 DOI: 10.1128/aem.71.12.8411-8418.2005] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Obligate lithotrophs (e.g., ammonia oxidizers) and facultative lithotrophs (e.g., CO and hydrogen oxidizers) collectively comprise a phylogenetically diverse functional group that contributes significantly to carbon and nitrogen cycles in soils and plays important roles in trace gas dynamics (e.g., carbon monoxide and nitrous and nitric oxides) that affect tropospheric chemistry and radiative forcing. In spite of their diverse physiologies, facultative and obligate lithotrophs typically possess the Calvin-Benson-Bassham cycle enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisCO). In an effort designed to understand the structure of lithotrophic communities in soil, genomic DNA extracts from surface (0 to 2 cm) and subsurface (5 to 7 cm) soils have been obtained from two sites in a Georgia agroecosystem (peanut and cotton plots) and an unmanaged pine stand (>50 years old). The extracts have been used in PCR amplifications of the cbbL gene for the rubisCO large subunit protein. cbbL PCR products were cloned, sequenced, and subjected to phylogenetic and statistical analyses. Numerous novel lineages affiliated with the form IC clade (one of four form I rubisCO clades), which is typified by facultative lithotrophs, comprised lithotrophic communities from all soils. One of the form IC clone sequences clustered with a form IC clade of ammonia-oxidizing Nitrosospira. Distinct assemblages were obtained from each of the sites and from surface and subsurface soils. The results suggest that lithotrophic populations respond differentially to plant type and land use, perhaps forming characteristic associations. The paucity of clone sequences attributed to ammonia-oxidizing bacteria indicates that even though ammonia oxidation occurs in the various soils, the relevant populations are small compared to those of facultative lithotrophs.
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Affiliation(s)
- J Tolli
- Darling Marine Center, University of Maine, Walpole, ME 04573, USA
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Sharma S, Aneja MK, Mayer J, Munch JC, Schloter M. Diversity of transcripts of nitrite reductase genes (nirK and nirS) in rhizospheres of grain legumes. Appl Environ Microbiol 2005; 71:2001-7. [PMID: 15812032 PMCID: PMC1082563 DOI: 10.1128/aem.71.4.2001-2007.2005] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2004] [Accepted: 10/28/2004] [Indexed: 11/20/2022] Open
Abstract
Transcription of the nirK and nirS genes coding for dissimilatory bacterial nitrite reductases was analyzed by reverse transcription PCR (RT-PCR) of mRNA isolated from rhizosphere samples of three economically important grain legumes at maturity: Vicia faba, Lupinus albus, and Pisum sativum. The nirK gene and transcripts could be detected in all the rhizosphere samples. In contrast, nirS could not be detected. Sampling variations were analyzed by comparing denaturing gradient gel electrophoresis profiles derived from nirK RT-PCR products. High similarity was observed between the replicates, and so one representative product per legume was cloned. Clones with the correct insert size were screened by restriction fragment length polymorphism by using the restriction enzyme MspI. The clones could be distributed into 12 different patterns. Patterns 1, 3, 4, 5, and 7 were common in clone libraries of the three rhizosphere types under study. Patterns 2, 9, 10, and 11 were absent from Pisum rhizospheres, while patterns 6, 8, and 12 were absent from the Vicia library. Pattern 1, which was the most dominant in the Vicia and Lupinus libraries, constituted about 25% of all clones. The Lupinus library had clones representing all 12 patterns, indicating it to be the most diverse among the three. Clones representative of each pattern were sequenced. All patterns grouped together forming a distinct cluster, which was divergent from previously described nirK sequences in the database. The study revealed a hitherto unknown diversity of denitrifiers in legume rhizospheres. A plant-dependent rhizosphere effect on the transcripts of a gene was evident.
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Affiliation(s)
- Shilpi Sharma
- Institute of Soil Ecology, GSF-National Research Center for Environment and Health, P.O. Box 1129, D-85764 Neuherberg, Germany.
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Holmes DE, Nevin KP, Lovley DR. In situ expression of nifD in Geobacteraceae in subsurface sediments. Appl Environ Microbiol 2005; 70:7251-9. [PMID: 15574924 PMCID: PMC535187 DOI: 10.1128/aem.70.12.7251-7259.2004] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In order to determine whether the metabolic state of Geobacteraceae involved in bioremediation of subsurface sediments might be inferred from levels of mRNA for key genes, in situ expression of nifD, a highly conserved gene involved in nitrogen fixation, was investigated. When Geobacter sulfurreducens was grown without a source of fixed nitrogen in chemostats with acetate provided as the limiting electron donor and Fe(III) as the electron acceptor, levels of nifD transcripts were 4 to 5 orders of magnitude higher than in chemostat cultures provided with ammonium. In contrast, the number of transcripts of recA and the 16S rRNA gene were slightly lower in the absence of ammonium. The addition of acetate to organic- and nitrogen-poor subsurface sediments stimulated the growth of Geobacteraceae and Fe(III) reduction, as well as the expression of nifD in Geobacteraceae. Levels of nifD transcripts in Geobacteraceae decreased more than 100-fold within 2 days after the addition of 100 microM ammonium, while levels of recA and total bacterial 16S rRNA in Geobacteraceae remained relatively constant. Ammonium amendments had no effect on rates of Fe(III) reduction in acetate-amended sediments or toluene degradation in petroleum-contaminated sediments, suggesting that other factors, such as the rate that Geobacteraceae could access Fe(III) oxides, limited Fe(III) reduction. These results demonstrate that it is possible to monitor one aspect of the in situ metabolic state of Geobacteraceae species in subsurface sediments via analysis of mRNA levels, which is the first step toward a more global analysis of in situ gene expression related to nutrient status and stress response during bioremediation by Geobacteraceae.
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Affiliation(s)
- Dawn E Holmes
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA.
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Nanba K, King GM, Dunfield K. Analysis of facultative lithotroph distribution and diversity on volcanic deposits by use of the large subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase. Appl Environ Microbiol 2004; 70:2245-53. [PMID: 15066819 PMCID: PMC383153 DOI: 10.1128/aem.70.4.2245-2253.2004] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A 492- to 495-bp fragment of the gene coding for the large subunit of the form I ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) (rbcL) was amplified by PCR from facultatively lithotrophic aerobic CO-oxidizing bacteria, colorless and purple sulfide-oxidizing microbial mats, and genomic DNA extracts from tephra and ash deposits from Kilauea volcano, for which atmospheric CO and hydrogen have been previously documented as important substrates. PCR products from the mats and volcanic sites were used to construct rbcL clone libraries. Phylogenetic analyses showed that the rbcL sequences from all isolates clustered with form IC rbcL sequences derived from facultative lithotrophs. In contrast, the microbial mat clone sequences clustered with sequences from obligate lithotrophs representative of form IA rbcL. Clone sequences from volcanic sites fell within the form IC clade, suggesting that these sites were dominated by facultative lithotrophs, an observation consistent with biogeochemical patterns at the sites. Based on phylogenetic and statistical analyses, clone libraries differed significantly among volcanic sites, indicating that they support distinct lithotrophic assemblages. Although some of the clone sequences were similar to known rbcL sequences, most were novel. Based on nucleotide diversity and average pairwise difference, a forested site and an 1894 lava flow were found to support the most diverse and least diverse lithotrophic populations, respectively. These indices of diversity were not correlated with rates of atmospheric CO and hydrogen uptake but were correlated with estimates of respiration and microbial biomass.
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Affiliation(s)
- K Nanba
- Laboratory of Aquatic Biology and Environmental Science, Graduate School of Agricultural Life Sciences, University of Tokyo, Bunkyo, Tokyo 113-8657, Japan
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Bazylinski DA, Dean AJ, Williams TJ, Long LK, Middleton SL, Dubbels BL. Chemolithoautotrophy in the marine, magnetotactic bacterial strains MV-1 and MV-2. Arch Microbiol 2004; 182:373-87. [PMID: 15338111 DOI: 10.1007/s00203-004-0716-y] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2004] [Revised: 06/14/2004] [Accepted: 07/19/2004] [Indexed: 11/28/2022]
Abstract
Magnetite-producing magnetotactic bacteria collected from the oxic-anoxic transition zone of chemically stratified marine environments characterized by O2/H2S inverse double gradients, contained internal S-rich inclusions resembling elemental S globules, suggesting they oxidize reduced S compounds that could support autotrophy. Two strains of marine magnetotactic bacteria, MV-1 and MV-2, isolated from such sites grew in O2-gradient media with H2S or thiosulfate (S2O3(2-)) as electron sources and O2 as electron acceptor or anaerobically with S2O3(2-) and N2O as electron acceptor, with bicarbonate (HCO3-)/CO2 as sole C source. Cells grown with H2S contained S-rich inclusions. Cells oxidized S2O3(2-) to sulfate (SO4(2-)). Both strains grew microaerobically with formate. Neither grew microaerobically with tetrathionate (S4O6(2-)), methanol, or Fe2+ as FeS, or siderite (FeCO3). Growth with S2O3(2-) and radiolabeled 14C-HCO3- showed that cell C was derived from HCO3-/CO2. Cell-free extracts showed ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) activity. Southern blot analyses indicated the presence of a form II RubisCO (cbbM) but no form I (cbbL) in both strains. cbbM and cbbQ, a putative post-translational activator of RubisCO, were identified in MV-1. MV-1 and MV-2 are thus chemolithoautotrophs that use the Calvin-Benson-Bassham pathway. cbbM was also identified in Magnetospirillum magnetotacticum. Thus, magnetotactic bacteria at the oxic-anoxic transition zone of chemically stratified aquatic environments are important in C cycling and primary productivity.
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Affiliation(s)
- Dennis A Bazylinski
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
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Nogales B, Timmis KN, Nedwell DB, Osborn AM. Detection and diversity of expressed denitrification genes in estuarine sediments after reverse transcription-PCR amplification from mRNA. Appl Environ Microbiol 2002; 68:5017-25. [PMID: 12324352 PMCID: PMC126436 DOI: 10.1128/aem.68.10.5017-5025.2002] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2002] [Accepted: 07/07/2002] [Indexed: 11/20/2022] Open
Abstract
The expression of five denitrification genes coding for two nitrate reductases (narG and napA), two nitrite reductases (nirS and nirK), and nitrous oxide reductase (nosZ) was analyzed by reverse transcription (RT)-PCR of mRNA extracted from two sediment samples obtained in the River Colne estuary (United Kingdom), which receives high nitrogen inputs and for which high denitrification rates have been observed. The presence of all five genes in both sediment samples was confirmed by PCR amplification from extracted DNA prior to analysis of gene expression. Only nirS and nosZ mRNAs were detected; nirS was detected directly as an RT-PCR amplification product, and nosZ was detected following Southern blot hybridization. This indicated that active expression of at least the nirS and nosZ genes was occurring in the sediments at the time of sampling. Amplified nirS RT-PCR products were cloned and analyzed by sequencing, and they were compared with amplified nirS gene sequences from isolates obtained from the same sediments. A high diversity of nirS sequences was observed. Most of the cloned nirS sequences retrieved were specific to one site or the other, which underlines differences in the compositions of the bacterial communities involved in denitrifrification in the two sediments analyzed.
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Affiliation(s)
- Balbina Nogales
- Department of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, United Kingdom.
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Parekh NR, Bardgett RD. Chapter 2 The characterisation of microbial communities in environmental samples. RADIOACTIVITY IN THE ENVIRONMENT 2002. [DOI: 10.1016/s1569-4860(02)80031-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Burns R, Stach J. Microbial ecology of soil biofilms: Substrate bioavailability, bioremediation and complexity. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0166-2481(02)80006-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Madrid VM, Taylor GT, Scranton MI, Chistoserdov AY. Phylogenetic diversity of bacterial and archaeal communities in the anoxic zone of the Cariaco Basin. Appl Environ Microbiol 2001; 67:1663-74. [PMID: 11282619 PMCID: PMC92783 DOI: 10.1128/aem.67.4.1663-1674.2001] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microbial community samples were collected from the anoxic zone of the Cariaco Basin at depths of 320, 500, and 1,310 m on a November 1996 cruise and were used to construct 16S ribosomal DNA libraries. Of 60 nonchimeric sequences in the 320-m library, 56 belonged to the epsilon subdivision of the Proteobacteria (epsilon-Proteobacteria) and 53 were closely related to ectosymbionts of Rimicaris exoculata and Alvinella pompejana, which are referred to here as epsilon symbiont relatives (ESR). The 500-m library contained sequences affiliated with the fibrobacteria, the Flexibacter-Cytophaga-Bacteroides division, the division Verrucomicrobia, the division Proteobacteria, and the OP3 candidate division. The Proteobacteria included members of the gamma, delta, epsilon and new candidate subdivisions, and gamma-proteobacterial sequences were dominant (25.6%) among the proteobacterial sequences. As in the 320-m library, the majority of the epsilon-proteobacteria belonged to the ESR group. The genus Fibrobacter and its relatives were the second largest group in the library (23.6%), followed by the delta-proteobacteria and the epsilon-proteobacteria. The 1,310-m library had the greatest diversity; 59 nonchimeric clones in the library contained 30 unique sequences belonging to the planctomycetes, the fibrobacteria, the Flexibacter-Cytophaga-Bacteroides division, the Proteobacteria, and the OP3 and OP8 candidate divisions. The proteobacteria included members of new candidate subdivisions and the beta, gamma, delta, and epsilon-subdivisions. ESR sequences were still present in the 1,310-m library but in a much lower proportion (8.5%). One archaeal sequence was present in the 500-m library (2% of all microorganisms in the library), and eight archaeal sequences were present in the 1,310-m library (13.6%). All archaeal sequences fell into two groups; two clones in the 1,310-m library belonged to the kingdom Crenarchaeota and the remaining sequences in both libraries belonged to the kingdom Euryarchaeota. The latter group appears to be related to the Eel-TA1f2 sequence, which belongs to an archaeon suggested to be able to oxidize methane anaerobically. Based on phylogenetic inferences and measurements of dark CO(2) fixation, we hypothesized that (i) the ESR are autotrophic anaerobic sulfide oxidizers, (ii) sulfate reduction and fermentative metabolism may be carried out by a large number of bacteria in the 500- and 1,310-m libraries, and (iii) members of the Euryarchaeota found in relatively large numbers in the 1,310-m library may be involved in anaerobic methane oxidation. Overall, the composition of microbial communities from the Cariaco Basin resembles the compositions of communities from several anaerobic sediments, supporting the hypothesis that the Cariaco Basin water column is similar to anaerobic sediments.
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Affiliation(s)
- V M Madrid
- Marine Sciences Research Center, State University of New York at Stony Brook, Stony Brook, NY 11794-5000, USA
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Kelly KM, Chistoserdov AY. Phylogenetic analysis of the succession of bacterial communities in the Great South Bay (Long Island). FEMS Microbiol Ecol 2001; 35:85-95. [PMID: 11248393 DOI: 10.1111/j.1574-6941.2001.tb00791.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Bacterial community composition and succession were examined over the course of the summer season in the Great South Bay, Long Island, NY, USA, using a 16S rDNA clone library approach. There was a progression of changes in dominant species in the libraries during the summer of 1997. The July library had several groups dominant, the SAR407 relatives of the alpha-Proteobacteria (24%) and the SAR86 (18%), sulfur-oxidizing symbiont relatives (8%) of the gamma-Proteobacteria, and unidentified Cytophaga-Flexibacter representatives (22%). In August, the Cytophaga-Flexibacter (Gelidibacter sp. and unidentified Cytophaga-Flexibacter representative) and Cyanobacteria (Synechococcus sp.) increased to 28% and 14%, respectively. High GC Gram-positives appeared at 18%, and beta-Proteobacteria (Ralstonia sp.) at 10%. By September these groups had either declined or were absent, while the SAR86 cluster, Pseudoalteromonas and Alteromonas of the gamma-Proteobacteria were dominant in the community (61%). The dominance of open ocean bacteria along with the presence of Aureococcus anophagefferens (Pelagophyceae) in July suggests possible open ocean coupling to bloom events. Many clones in this study were related to previously described clones from a wide distribution of marine environments, substantiating the cosmopolitan nature of pelagic bacteria. Only one isolated bacterium was closely related to 16S rDNA found in the August library.
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Affiliation(s)
- K M. Kelly
- Marine Sciences Research Center, State University of New York at Stony Brook, 11794-5000, Stony Brook, NY, USA
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Wyman M, Davies JT, Crawford DW, Purdie DA. Molecular and physiological responses of two classes of marine chromophytic phytoplankton (Diatoms and prymnesiophytes) during the development of nutrient-stimulated blooms. Appl Environ Microbiol 2000; 66:2349-57. [PMID: 10831410 PMCID: PMC110529 DOI: 10.1128/aem.66.6.2349-2357.2000] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Generic taxon-specific DNA probes that target an internal region of the gene (rbcL) encoding the large subunit of ribulose-1, 5-bisphosphate carboxylase/oxygenase (RubisCO) were developed for two groups of marine phytoplankton (diatoms and prymnesiophytes). The specificity and utility of the probes were evaluated in the laboratory and also during a 1-month mesocosm experiment in which we investigated the temporal variability in RubisCO gene expression and primary production in response to inorganic nutrient enrichment. We found that the onset of successive bloom events dominated by each of the two classes of chromophyte algae was associated with marked taxon-specific increases in rbcL transcription rates. These observations suggest that measurements of RubisCO gene expression can provide an early indicator of the development of phytoplankton blooms and may also be useful in predicting which taxa are likely to dominate a bloom.
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Affiliation(s)
- M Wyman
- Department of Biological Sciences, University of Stirling, Stirling FK9 4LA, United Kingdom.
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Paerl HW, Pinckney JL, Steppe TF. Cyanobacterial-bacterial mat consortia: examining the functional unit of microbial survival and growth in extreme environments. Environ Microbiol 2000; 2:11-26. [PMID: 11243256 DOI: 10.1046/j.1462-2920.2000.00071.x] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cyanobacterial-bacterial consortial associations are taxonomically complex, metabolically interactive, self-sustaining prokaryotic communities representing pioneer and often the only biota inhabiting extreme aquatic and terrestrial environments. Laminated mats and aggregates exemplify such communities. The fossil record indicates that these associations represent the earliest extant inhabitants and modifiers (i.e. anoxic to oxic conditions) of the Earth's biosphere. Present-day consortia flourish in physically and chemically stressed environments, including nutrient-deplete, hypersaline, calcified, desiccated and high-irradiance ecosystems ranging from the tropics to polar regions. Consortial members exhibit extensive metabolic diversification, but have remained structurally simple. Structural simplicity, while advantageous in countering environmental extremes, presents a 'packaging problem' with regard to compartmentalizing potentially cross-inhibitory aerobic versus anaerobic growth processes. To circumvent these metabolic constraints, phototrophic cyanobacteria and microheterotrophs orient along microscale chemical (i.e. O2, pH, Eh) gradients to meet and optimize the biogeochemical processes (C, N, S cycling) essential for survival, growth and the maintenance of genetic diversity, needed to sustain life. Microscale ecophysiological, analytical, molecular (immunological and nucleic acid) techniques have helped to develop a mechanistic basis for understanding consortial growth and survival under extreme environmental conditions on Earth. Consortia are ideal model systems for developing a process-based understanding of the structural and functional requirements for life in extreme environments representative of the Earth's earliest biosphere and possibly other planets.
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Affiliation(s)
- H W Paerl
- Institute of Marine Sciences, University of North Carolina at Chapel Hill, 28557, USA.
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Wilson MS, Bakermans C, Madsen EL. In situ, real-time catabolic gene expression: extraction and characterization of naphthalene dioxygenase mRNA transcripts from groundwater. Appl Environ Microbiol 1999; 65:80-7. [PMID: 9872763 PMCID: PMC90986 DOI: 10.1128/aem.65.1.80-87.1999] [Citation(s) in RCA: 120] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We developed procedures for isolating and characterizing in situ-transcribed mRNA from groundwater microorganisms catabolizing naphthalene at a coal tar waste-contaminated site. Groundwater was pumped through 0.22-microm-pore-size filters, which were then frozen in dry ice-ethanol. RNA was extracted from the frozen filters by boiling sodium dodecyl sulfate lysis and acidic phenol-chloroform extraction. Transcript characterization was performed with a series of PCR primers designed to amplify nahAc homologs. Several primer pairs were found to amplify nahAc homologs representing the entire diversity of the naphthalene-degrading genes. The environmental RNA extract was reverse transcribed, and the resultant mixture of cDNAs was amplified by PCR. A digoxigenin-labeled probe mixture was produced by PCR amplification of groundwater cDNA. This probe mixture hybridized under stringent conditions with the corresponding PCR products from naphthalene-degrading bacteria carrying a variety of nahAc homologs, indicating that diverse dioxygenase transcripts had been retrieved from groundwater. Diluted and undiluted cDNA preparations were independently amplified, and 28 of the resulting PCR products were cloned and sequenced. Sequence comparisons revealed two major groups related to the dioxygenase genes ndoB and dntAc, previously cloned from Pseudomonas putida NCIB 9816-4 and Burkholderia sp. strain DNT, respectively. A distinctive subgroup of sequences was found only in experiments performed with the undiluted cDNA preparation. To our knowledge, these results are the first to directly document in situ transcription of genes encoding naphthalene catabolism at a contaminated site by indigenous microorganisms. The retrieved sequences represent greater diversity than has been detected at the study site by culture-based approaches.
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Affiliation(s)
- M S Wilson
- Section of Microbiology, Division of Biological Sciences, Cornell University, Ithaca New York 14853, USA
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Wawer C, Jetten MS, Muyzer G. Genetic diversity and expression of the [NiFe] hydrogenase large-subunit gene of Desulfovibrio spp. in environmental samples. Appl Environ Microbiol 1997; 63:4360-9. [PMID: 9361423 PMCID: PMC168756 DOI: 10.1128/aem.63.11.4360-4369.1997] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The genetic diversity and expression of the [NiFe] hydrogenase large-subunit gene of Desulfovibrio spp. in environmental samples were determined in order to show in parallel the existing and active members of Desulfovibrio populations. DNA and total RNA were extracted from different anaerobic bioreactor samples; RNA was transcribed into cDNA. Subsequently, PCR was performed to amplify a ca.-440-bp fragment of the [NiFe] hydrogenase large-subunit gene and its mRNA. Denaturing gradient gel electrophoresis analysis was used to separate the PCR products according to their sequence and thereby to visualize the individual community members. Desulfovibrio strains corresponding to amplified [NiFe] hydrogenase transcripts were regarded as metabolically active, because in pure cultures transcripts were detectable in exponentially growing cells but not in cultures in the stationary phase. DNA sequencing and comparative sequence analysis were used to identify the detected organisms on the basis of their [NiFe] hydrogenase sequences. The genes of characterized Desulfovibrio spp. showed a considerable extent of divergence (ca. 30%), whereas sequences obtained from bacterial populations of the bioreactors showed a low level of variation and indicated the coexistence of closely related strains probably belonging to the species Desulfovibrio sulfodismutans. Under methanogenic conditions, all detected populations were active; under denitrifying conditions, no [NiFe] hydrogenase mRNA was visible. Changes in activity and composition of Desulfovibrio populations caused by changes in the environmental conditions could be monitored by using the approach described in this study.
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Affiliation(s)
- C Wawer
- Molecular Ecology Group, Max-Planck-Institute for Marine Microbiology, Bremen, Germany
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Pichard SL, Campbell L, Paul JH. Diversity of the ribulose bisphosphate carboxylase/oxygenase form I gene (rbcL) in natural phytoplankton communities. Appl Environ Microbiol 1997; 63:3600-6. [PMID: 9293012 PMCID: PMC168667 DOI: 10.1128/aem.63.9.3600-3606.1997] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The phytoplankton of the world's oceans play an integral part in global carbon cycling and food webs by conversion of carbon dioxide into organic carbon. They accomplish this task through the action of the Calvin cycle enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). Here we have investigated the phylogenetic diversity in the form I rbcL locus in natural phytoplankton communities of the open ocean and representative clones of marine autotrophic picoplankton by mRNA or DNA amplification and sequencing of a 480 to 483 bp internal fragment of this gene. Five gene sequences were recovered from nucleic acids of natural phytoplankton communities of the Gulf of Mexico. The rbcL genes of two Prochlorococcus isolates and one Synechococcus strain (WH8007) were also sequenced. Sequences were aligned with the database of rbcL genes and subjected to both neighbor-joining and parsimony analyses. The five sequences from the natural phytoplankton community spanned nearly the entire diversity of characterized form I rbcL genes, with some sequences closely related to isolates such as Synechococcus and Prochlorococcus (forms IA and I) and prymnesiophyte algae (form ID), while other sequences were deeply rooted. Unexpectedly, the deep euphotic zone contained an organism that possesses a transcriptionally active rbcL gene closely related to that of a recently characterized manganese-oxidizing bacterium, suggesting that such chemoautotrophs may contribute to the diversity of carbon-fixing organisms in the marine euphotic zone.
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Affiliation(s)
- S L Pichard
- Department of Marine Science, University of South Florida, St. Petersburg 33701, USA
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