Bacterial community structure and activity of sulfate reducing bacteria in a membrane aerated biofilm analyzed by microsensor and molecular techniques

2014 ◽  
Vol 111 (11) ◽  
pp. 2155-2162 ◽  
Author(s):  
Hong Liu ◽  
Shuying Tan ◽  
Zhiya Sheng ◽  
Yang Liu ◽  
Tong Yu
2020 ◽  
Vol 11 ◽  
Author(s):  
Tingting Zhang ◽  
Xi Xiao ◽  
Songze Chen ◽  
Jing Zhao ◽  
Zongheng Chen ◽  
...  

Cold seep ecosystems are developed from methane-rich fluids in organic rich continental slopes, which are the source of various dense microbial and faunal populations. Extensive studies have been conducted on microbial populations in this unique environment; most of them were based on DNA, which could not resolve the activity of extant organisms. In this study, RNA and DNA analyses were performed to evaluate the active archaeal and bacterial communities and their network correlations, particularly those participating in the methane cycle at three sites of newly developed cold seeps in the northern South China Sea (nSCS). The results showed that both archaeal and bacterial communities were significantly different at the RNA and DNA levels, revealing a higher abundance of methane-metabolizing archaea and sulfate-reducing bacteria in RNA sequencing libraries. Site ROV07-01, which exhibited extensive accumulation of deceased Calyptogena clam shells, was highly developed, and showed diverse and active anaerobic archaeal methanotrophs (ANME)-2a/b and sulfate-reducing bacteria from RNA libraries. Site ROV07-02, located near carbonate crusts with few clam shell debris, appeared to be poorly developed, less anaerobic and less active. Site ROV05-02, colonized by living Calyptogena clams, could likely be intermediary between ROV07-01 and ROV07-02, showing abundant ANME-2dI and sulfate-reducing bacteria in RNA libraries. The high-proportions of ANME-2dI, with respect to ANME-2dII in the site ROV07-01 was the first report from nSCS, which could be associated with recently developed cold seeps. Both ANME-2dI and ANME-2a/b showed close networked relationships with sulfate-reducing bacteria; however, they were not associated with the same microbial operational taxonomic units (OTUs). Based on the geochemical gradients and the megafaunal settlements as well as the niche specificities and syntrophic relationships, ANMEs appeared to change in community structure with the evolution of cold seeps, which may be associated with the heterogeneity of their geochemical processes. This study enriched our understanding of more active sulfate-dependent anaerobic oxidation of methane (AOM) in poorly developed and active cold seep sediments by contrasting DNA- and RNA-derived community structure and activity indicators.


2012 ◽  
Vol 83 (3) ◽  
pp. 724-737 ◽  
Author(s):  
Ludovic Giloteaux ◽  
Robert Duran ◽  
Corinne Casiot ◽  
Odile Bruneel ◽  
Françoise Elbaz-Poulichet ◽  
...  

2020 ◽  
Vol 27 (3) ◽  
pp. 197
Author(s):  
Yuli Siti Fatma ◽  
Iman Rusmana ◽  
Aris Tri Wahyudi ◽  
Hamim Hamim

Paddy field is one of the anthropogenic sources that produce greenhouse gases emission. This study aimed to investigate the impact of methanotrophic and N2O-reducing bacterial inoculation on CH4 and N2O emissions, paddy growth and bacterial community structure in paddy field. Two treatments of 100% synthetic fertilizer (250 kg urea/ha) without biofertilizer and 50% synthetic fertilizer (125 kg urea/ha) with biofertilizer consisted of methanotrophic and N2O-reducing bacteria were applied in the paddy field. Inoculation of methanotrophic and N2O-reducing bacteria was able to reduce CH4 and N2O emission up to 4.19 mg CH4/m2/day and 351.29 µg N2O/m2/day, respectively. Those bacterial applications were also able to increase paddy growth and yield productivity. According to DGGE profile, inoculation of the biofertilizer seemed to have a transient impact on bacterial communities in paddy soil at 36 days after transplanting (DAT) which showed the lowest similarity with all samples (a similarity index of 0.68). DGGE bands successfully excised have closest relative to uncultured bacteria which comprised 5 phyla, i.e. Proteobacteria (Alphaproteobacteria and Deltaproteobacteria), Nitrospirae, Actinobacteria, Firmicutes, and Acidobacteria. In this study, Alphaproteobacteria was the most dominant phylum. We provide  basic information for developing the biofertilizer which supports sustainable agriculture.


2018 ◽  
Vol 2 (2) ◽  
pp. 1
Author(s):  
Tyas Nyonita Punjungsari

The biofilm is a microbial community structure formed on the zeolite surface in a sulfate reduction bioreactor and Cu deposition using a SRB consortium . The biofilm soluble microbial solvent is expected to have the capability in sulfate reduction and Cu deposition. Characterization of isolates is required for the optimization of pure culture . The aim of this study is to isolate and characterize the biofilm sulfate reducing bacteria in the sulfate reduction bioreactor and the precipitation of Cu in Batch Culture by a consortium of Sulfate Reducing Bacteria. The method used in this study cultivation was done by using postgate B medium, isolation was done by diluting biofilm on NaCl salt, bacteria grown on NB and postgate B media, characterization done by morphology and biochemistry. There were 3 isolates of B1 (Metylobacterium ), B3 ( Desulfucoccus ), and B2 ( Desulfobacter ). B3 ( Desulfococcus) has the best ability to reduce sulfate and Cu precipitation.Keywords : Sulfur Reducing Bacteria (SRB), Biofilm, Sulfate, Cu. Received: 26 August, 2017; Accepter: 10 September, 2017 


2020 ◽  
Vol 85 ◽  
pp. 1-18
Author(s):  
RC Seballos ◽  
KH Wyatt ◽  
RJ Bernot ◽  
SP Brown ◽  
S Chandra ◽  
...  

Heterotrophic bacteria play a key role in ecosystem processes, but little is known about the factors that shape bacterial community structure in aquatic biofilms, especially in lakes. We used molecular techniques (16S rRNA) to evaluate resource controls on biofilm bacterial community structure in an oligotrophic subalpine lake. We manipulated nutrients (nitrogen and phosphorus; NP) and glucose (G) on inorganic (rock) and organic (wood) substrates under light and dark conditions (i.e. with and without autotrophy, respectively) in a full factorial design using nutrient diffusing substrates in situ for 20 d. Distinct patterns of separation in community structure between treatments with nutrients (NP, NP+G) and without nutrients (control, G-only) indicated that community structure was more strongly influenced by nutrients than organic matter irrespective of substrate type or light availability. Further separation in community structure between treatments with nutrients only (NP) and nutrients with glucose (NP+G) on both organic and inorganic substrates indicated that once nutrient limitation was alleviated, organic matter quality played an important role in shaping community structure. Differences in the relative abundance of 6 phyla, 3 classes, and 19 genera among treatments revealed (1) contrasting taxa-specific resource requirements, (2) the influence of interspecific interactions on composition, and (3) the potential for individual taxa to participate in the decomposition of recalcitrant organic matter. Our findings provide insight into the role that nutrients and organic matter quality play in shaping bacterial community structure, which is a critical step in bridging the knowledge gap between microbial composition and ecosystem function within aquatic environments.


Author(s):  
Avishek Dutta ◽  
Fernando Valle ◽  
Thomas Goldman ◽  
Jeff Keating ◽  
Ellen Burke ◽  
...  

Sulfate-reducing bacteria (SRB) are one of the main sources of biogenic H 2 S generation in oil reservoirs. Excess H 2 S production in these systems leads to oil biosouring, which causes operational risks, health hazards and can increase the cost of refining crude oil. Nitrate salts are often added to the system to suppress sulfidogenesis. Because SRB populations can persist in biofilms even after nitrate treatment, identifying shifts in the sessile community is crucial for successful mitigation. However, sampling the sessile community is hampered by its inaccessibility. Here we use the results of a long-term (148 days) ex situ experiment to identify particular sessile community members from observations of the sample waste stream. Microbial community structure was determined for 731 samples across twenty bioreactors using 16S rRNA gene sequencing. By associating microbial community structure with specific steps in the mitigation process, we could distinguish between taxa associated with H 2 S production and mitigation. After initiation of nitrate treatment, certain SRB populations increased in the planktonic community during critical time points, indicating the dissociation of SRBs from the biofilm. Predicted relative abundances of the dissimilatory sulfate reduction pathway also increased during the critical time points. Here, by analyzing the planktonic community structure, we describe a general method that uses high-throughput amplicon sequencing, metabolic inferences, and cell abundance data to identify successful biofilm mitigation. We anticipate that our approach is also applicable to other systems where biofilms must be mitigated but cannot be easily sampled. Importance Microbial biofilms are commonly present in many industrial processes and can negatively impact performance and safety. Within the oil industry, subterranean biofilms cause biosouring with implications for oil quality, cost, occupational health, and the environment. Because these biofilms cannot be directly sampled, methods are needed to indirectly assess the success of mitigation measures. This study demonstrates how the planktonic microbial community can be used to assess the dissociation of SRB-containing biofilms. We found that an increase in the abundance of a specific SRB population in the effluent after nitrate treatment can be used as a potential indicator for the successful mitigation of biofilm-forming SRBs. Moreover, a method for determining critical time points for detecting potential indicators is suggested. This study expands our knowledge in improving mitigation strategies for biosouring and could have broader implications in other systems where biofilms lead to adverse consequences.


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