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Wang J, Qian F, Liu X, Liu W, Wang S, Shen Y. Cultivation and characteristics of partial nitrification granular sludge in a sequencing batch reactor inoculated with heterotrophic granules. Appl Microbiol Biotechnol 2016; 100:9381-9391. [PMID: 27557719 DOI: 10.1007/s00253-016-7797-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Revised: 06/12/2016] [Accepted: 08/09/2016] [Indexed: 01/01/2023]
Abstract
The aim of this study was to develop a simple operation strategy for the cultivation of partial nitrification granules (PNGs) treating an autotrophic medium. For this strategy, aerobic granular sludge adapted to high concentration organics removal was seeded in a sequencing batch reactor (SBR) with a height/diameter ratio of 3.8, and the ratio of organics to the ammonia nitrogen-loading rate (C/N ratio) in the influent was employed as the main control parameter to start up the partial nitrification process. After 86 days of operation, the nitrite accumulation rate reached 1.44 kg/(m3 day) in the SBR, and the removal efficiency of ammonia nitrogen (NH4+-N) was over 95 %. The PNGs showed a dense and compact structure, with an excellent settling ability, a typical extracellular polymeric substance (EPS) composition, and a high ammonia oxidation activity. The high-throughput pyrosequencing results indicated that the microbial community structure in the granules was significantly influenced by the C/N ratio, and ammonia-oxidizing bacteria (AOB), including the r-strategist Nitrosomonas and k-strategist Nitrosospira genre, which accounted for approximately 40 % of the total biomass at the end of operation. The effective suppression of nitrite-oxidizing bacteria (NOB) growth was attributed to oxygen competition on the granular surface among functional bacteria, as well as the high free ammonia or free nitrous acid concentrations during the aeration period.
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Affiliation(s)
- Jianfang Wang
- College of Environmental Science and Engineering, Suzhou University of Science and Technology, No. 1 Kerui Road, 215009, Suzhou, People's Republic of China.,Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, No. 1 Kerui Road, 215009, Suzhou, People's Republic of China.,College of Tianping, Suzhou University of Science and Technology, No. 55 Changjiang Road, 215009, Suzhou, People's Republic of China
| | - Feiyue Qian
- College of Environmental Science and Engineering, Suzhou University of Science and Technology, No. 1 Kerui Road, 215009, Suzhou, People's Republic of China. .,Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, No. 1 Kerui Road, 215009, Suzhou, People's Republic of China.
| | - Xiaopeng Liu
- College of Environmental Science and Engineering, Suzhou University of Science and Technology, No. 1 Kerui Road, 215009, Suzhou, People's Republic of China
| | - Wenru Liu
- College of Environmental Science and Engineering, Tongji University, No. 1239 Siping Road, 200092, Shanghai, People's Republic of China
| | - Shuyong Wang
- College of Environmental Science and Engineering, Suzhou University of Science and Technology, No. 1 Kerui Road, 215009, Suzhou, People's Republic of China
| | - Yaoliang Shen
- College of Environmental Science and Engineering, Suzhou University of Science and Technology, No. 1 Kerui Road, 215009, Suzhou, People's Republic of China.,Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, No. 1 Kerui Road, 215009, Suzhou, People's Republic of China
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Song C, Sun XF, Xia PF, Wang YK, Wang SG. Investigation of fate and behavior of tetracycline in nitrifying sludge system. RSC Adv 2015. [DOI: 10.1039/c5ra15813c] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This study aims to investigate the fate and behavior of tetracycline (TC) in nitrifying sludge system, as well as the effects of TC dosage on sludge performance.
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Affiliation(s)
- Chao Song
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse
- School of Environmental Science and Engineering
- Shandong University
- Jinan 250100
- China
| | - Xue-Fei Sun
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse
- School of Environmental Science and Engineering
- Shandong University
- Jinan 250100
- China
| | - Peng-Fei Xia
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse
- School of Environmental Science and Engineering
- Shandong University
- Jinan 250100
- China
| | - Yun-Kun Wang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse
- School of Environmental Science and Engineering
- Shandong University
- Jinan 250100
- China
| | - Shu-Guang Wang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse
- School of Environmental Science and Engineering
- Shandong University
- Jinan 250100
- China
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Mota CR, So MJ, de los Reyes FL. Identification of nitrite-reducing bacteria using sequential mRNA fluorescence in situ hybridization and fluorescence-assisted cell sorting. MICROBIAL ECOLOGY 2012; 64:256-267. [PMID: 22370876 DOI: 10.1007/s00248-012-0018-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 01/25/2012] [Indexed: 05/31/2023]
Abstract
Sequential mRNA fluorescence in situ hybridization (mRNA FISH) and fluorescence-assisted cell sorting (SmRFF) was used for the identification of nitrite-reducing bacteria in mixed microbial communities. An oligonucleotide probe labeled with horseradish peroxidase (HRP) was used to target mRNA of nirS, the gene that encodes nitrite reductase, the enzyme responsible for the dissimilatory reduction of nitrite to nitric oxide. Clones for nirS expression were constructed and used to provide proof of concept for the SmRFF method. In addition, cells from pure cultures of Pseudomonas stutzeri and denitrifying activated sludge were hybridized with the HRP probe, and tyramide signal amplification was performed, conferring a strongly fluorescent signal to cells containing nirS mRNA. Flow cytometry-assisted cell sorting was used to detect and physically separate two subgroups from a mixed microbial community: non-fluorescent cells and an enrichment of fluorescent, nitrite-reducing cells. Denaturing gradient gel electrophoresis (DGGE) and subsequent sequencing of 16S ribosomal RNA (rRNA) genes were used to compare the fragments amplified from the two sorted subgroups. Sequences from bands isolated from DGGE profiles suggested that the dominant, active nitrite reducers were closely related to Acidovorax BSB421. Furthermore, following mRNA FISH detection of nitrite-reducing bacteria, 16S rRNA FISH was used to detect ammonia-oxidizing and nitrite-oxidizing bacteria on the same activated sludge sample. We believe that the molecular approach described can be useful as a tool to help address the longstanding challenge of linking function to identity in natural and engineered habitats.
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Affiliation(s)
- Cesar R Mota
- School of Civil Engineering and Geosciences, Newcastle University, Cassie Building, Newcastle, UK
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Saidi MN, Jbir R, Ghorbel I, Namsi A, Drira N, Gargouri-Bouzid R. Brittle leaf disease induces an oxidative stress and decreases the expression of manganese-related genes in date palm (Phoenix dactylifera L.). PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2012; 50:1-7. [PMID: 22099513 DOI: 10.1016/j.plaphy.2011.09.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Accepted: 09/26/2011] [Indexed: 05/31/2023]
Abstract
In Tunisia, date orchards are being decimated by a disease called brittle leaf disease of unknown origin. Previous studies reported that affected soils, roots and leaves were manganese deficient. In this study, we investigated the biochemical and molecular response of MFC-affected date palms to the oxidative stress generated by manganese deficiency. Both the malondialdehyde (MDA) content which is indicative of lipid peroxidation and the activities of antioxidant enzyme were measured in affected leaves and roots. The expression profiles of oxidative stress-related genes encoding superoxide dismutases and peroxidases were also investigated. The data show that the MDA concentration increased but not significantly in affected leaves. However, such MDA increase was significant in roots of MFC-affected plants. The total superoxide dismutase (SOD) activity increased in affected leaves and roots, while RT-PCR experiments showed that MnSOD RNA decreased in affected leaves and roots unlike FeSOD and Cu/Zn-SOD RNA expression increased in these organs. In addition ascorbate peroxidase (APx) and glutathione peroxidase (GPx) RNA expression increased in diseased leaves and roots.
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Affiliation(s)
- Mohammed Najib Saidi
- Laboratoire des Biotechnologies Végétales Appliquées à l'Amélioration des Cultures, Ecole Nationale d'Ingénieurs de Sfax, Route Soukra Km 4, B.P 1173, 3038 Sfax, Tunisia.
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Maixner F, Noguera DR, Anneser B, Stoecker K, Wegl G, Wagner M, Daims H. Nitrite concentration influences the population structure of Nitrospira-like bacteria. Environ Microbiol 2006; 8:1487-95. [PMID: 16872410 DOI: 10.1111/j.1462-2920.2006.01033.x] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Chemolithoautotrophic nitrite oxidizers of the genus Nitrospira are a monophyletic but diverse group of organisms, are widely distributed in many natural habitats, and play a key role in nitrogen elimination during biological wastewater treatment. Phylogenetic analyses of cloned 16S rRNA genes and fluorescence in situ hybridization with newly developed rRNA-targeted oligonucleotide probes revealed coexistence of uncultured members of sublineages I and II of the genus Nitrospira in biofilm and activated sludge samples taken from nitrifying wastewater treatment plants. Quantitative microscopic analyses of their spatial arrangement relative to ammonia oxidizers in the biofilm and activated sludge flocs showed that members of the Nitrospira sublineage I occurred significantly more often in immediate vicinity to ammonia oxidizers than would be expected from random community assembly while such a relationship was not observed for Nitrospira sublineage II. This spatial distribution suggested a niche differentiation of these coexisting Nitrospira populations with respect to their preferred concentrations of nitrite. This hypothesis was tested by mathematical modelling of nitrite consumption and resulting nitrite gradients in nitrifying biofilms and by quantifying the abundance of sublineage I and II Nitrospira in activated sludge during incubations with nitrite in different concentrations. Consistent with the observed localization patterns, a higher nitrite concentration selected for sublineage I but suppressed sublineage II Nitrospira.
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Affiliation(s)
- Frank Maixner
- Department für Mikrobielle Okologie, Universität Wien, Althanstrasse 14, A-1090 Vienna, Austria
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