Effect of lead, mercury and cadmium on a sulphate-reducing bacterium

Bharathi, P. A. Loka; Sathe, V. G.; Chandramohan, D.

doi:10.1016/0269-7491(90)90072-k

Cited by 47 publications

(40 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…4B). Additionally, the heavy metal Cd appears to be an important factor that influences the diazotrophic community structure, which could be due to the strong toxicity of Cd to diazotrophs and sulfate-reducing bacteria, as noted in previous studies (66,67).…”

Section: Discussionmentioning

confidence: 72%

Seagrass (Zostera marina) Colonization Promotes the Accumulation of Diazotrophic Bacteria and Alters the Relative Abundances of Specific Bacterial Lineages Involved in Benthic Carbon and Sulfur Cycling

Sun

Zhang

et al. 2015

Appl Environ Microbiol

View full text Add to dashboard Cite

dSeagrass colonization changes the chemistry and biogeochemical cycles mediated by microbes in coastal sediments. In this study, we molecularly characterized the diazotrophic assemblages and entire bacterial community in surface sediments of a Zostera marina-colonized coastal lagoon in northern China. Higher nitrogenase gene (nifH) copy numbers were detected in the sediments from the vegetated region than in the sediments from the unvegetated region nearby. The nifH phylotypes detected were mostly affiliated with the Geobacteraceae, Desulfobulbus, Desulfocapsa, and Pseudomonas. Redundancy analysis based on terminal restriction fragment length polymorphism analysis showed that the distribution of nifH genotypes was mostly shaped by the ratio of total organic carbon to total organic nitrogen, the concentration of cadmium in the sediments, and the pH of the overlying water. High-throughput sequencing and phylogenetic analyses of bacterial 16S rRNA genes also indicated the presence of Geobacteraceae and Desulfobulbaceae phylotypes in these samples. A comparison of these results with those of previous studies suggests the prevalence and predominance of iron(III)-reducing Geobacteraceae and sulfate-reducing Desulfobulbaceae diazotrophs in coastal sedimentary environments. Although the entire bacterial community structure was not significantly different between these two niches, Desulfococcus (Deltaproteobacteria) and Anaerolineae (Chloroflexi) presented with much higher proportions in the vegetated sediments, and Flavobacteriaceae (Bacteroidetes) occurred more frequently in the bare sediments. These data suggest that the high bioavailability of organic matter (indicated by relatively lower carbon-to-nitrogen ratios) and the less-reducing anaerobic condition in vegetated sediments may favor Desulfococcus and Anaerolineae lineages, which are potentially important populations in benthic carbon and sulfur cycling in the highly productive seagrass ecosystem. Sediments colonized by seagrass in shallow estuarine and coastal environments are hot spots of microbial activities. Seagrass meadows enrich the sediment carbon matter by exuding dissolved organic carbon (DOC) through their roots and trapping organic particles from the overlying water (1). Due to the effects of seagrass on nutrient deposition, retention, and mineralization from organic matter, the nutrients in pore water are often richer in seagrass sediments than in sediments from unvegetated regions (1-3). Seagrass roots also release photosynthesis-produced O 2 into sediments, which results in less-reducing conditions in seagrass meadows than unvegetated sediments and contributes to the prevention of the accumulation of sulfides, the toxic products of sulfate reduction in anaerobic sedimentary environments that could play a role in dieback events in seagrass meadows (1, 4). Higher bacterial populations and activities (particularly bacterium-mediated sulfate reduction) are usually found in seagrass-vegetated sites and not in unvegetated sediments (5-8).Because the gro...

show abstract

Section: Discussionmentioning

confidence: 72%

Seagrass (Zostera marina) Colonization Promotes the Accumulation of Diazotrophic Bacteria and Alters the Relative Abundances of Specific Bacterial Lineages Involved in Benthic Carbon and Sulfur Cycling

Sun

Zhang

et al. 2015

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…It was observed that a pure culture of SRB can tolerate 0.3-0.8 mM of Cu (Booth and Mercer 1963), similar to what was observed by Saleh et al (1964), who also reported that SRB can tolerate around 1.5 mM of Zn. The use of 0.35 mM of Cd and 0.4 mM of Pb induced 50 % inhibition in a SRB pure culture (Loka Bharathi et al 1990), while Desulfovibrio desulfuricans was reported to be sensitive to concentrations of Ni and Zn above 0.17 and 0.20 mM, respectively (Poulson et al 1997). The effects of Cu and Zn in a mixed culture of acetate-utilizing bacteria were analysed and observed a 50 % inhibition of 0.17 mM for Cu and 0.25 mM for Zn (Utgikar et al 2001).…”

Section: Effects Of Heavy Metals On Srbmentioning

confidence: 95%

Methanogens, sulphate and heavy metals: a complex system

Paulo

Stams

Sousa

2015

Rev Environ Sci Biotechnol

117

View full text Add to dashboard Cite

Anaerobic digestion (AD) is a well-established technology used for the treatment of wastes and wastewaters with high organic content. During AD organic matter is converted stepwise to methanecontaining biogas-a renewable energy carrier. Methane production occurs in the last AD step and relies on methanogens, which are rather sensitive to some contaminants commonly found in wastewaters (e.g. heavy metals), or easily outcompeted by other groups of microorganisms (e.g. sulphate reducing bacteria, SRB). This review gives an overview of previous research and pilot-scale studies that shed some light on the effects of sulphate and heavy metals on methanogenesis. Despite the numerous studies on this subject, comparison is not always possible due to differences in the experimental conditions used and parameters explained. An overview of the possible benefits of methanogens and SRB co-habitation is also covered. Small amounts of sulphide produced by SRB can precipitate with metals, neutralising the negative effects of sulphide accumulation and free heavy metals on methanogenesis. Knowledge on how to untangle and balance sulphate reduction and methanogenesis is crucial to take advantage of the potential for the utilisation of biogenic sulphide as a metal detoxification agent with minimal loss in methane production in anaerobic digesters.

show abstract

“…Reports regarding the toxicity of heavy metals to SRB (8,10,24,27,30,39,42,46,50) have generally been qualitative in nature and have used microbial media designed to optimize growth rather than to examine metal toxicity. Often in these studies the authors reported abiotic formation of metal precipitates and/or significant metal complexation that prevented meaningful quantitative assessment of metal toxicity.…”

mentioning

confidence: 99%