scholarly journals Isolation of sulfate-reducing bacteria from Tunisian marine sediments and description of Desulfovibrio bizertensis sp. nov.

2006 ◽  
Vol 56 (12) ◽  
pp. 2909-2913 ◽  
Author(s):  
Olfa Haouari ◽  
Marie-Laure Fardeau ◽  
Laurence Casalot ◽  
Jean-Luc Tholozan ◽  
Moktar Hamdi ◽  
...  

Several strains of sulfate-reducing bacteria were isolated from marine sediments recovered near Tunis, Korbous and Bizerte, Tunisia. They all showed characteristics consistent with members of the genus Desulfovibrio. One of these strains, designated MB3T, was characterized further. Cells of strain MB3T were slender, curved, vibrio-shaped, motile, Gram-negative, non-spore-forming rods. They were positive for desulfoviridin as bisulfite reductase. Strain MB3T grew at temperatures of 15–45 °C (optimum 40 °C) and at pH 6.0–8.1 (optimum pH 7.0). NaCl was required for growth (optimum 20 g NaCl l−1). Strain MB3T utilized H2 in the presence of acetate with sulfate as electron acceptor. It also utilized lactate, ethanol, pyruvate, malate, fumarate, succinate, butanol and propanol as electron donors. Lactate was oxidized incompletely to acetate. Strain MB3T fermented pyruvate and fumarate (poorly). Electron acceptors utilized included sulfate, sulfite, thiosulfate, elemental sulfur and fumarate, but not nitrate or nitrite. The G+C content of the genomic DNA was 51 mol%. On the basis of genotypic, phenotypic and phylogenetic characteristics, strain MB3T (=DSM 18034T=NCIMB 14199T) is proposed as the type strain of a novel species, Desulfovibrio bizertensis sp. nov.

2006 ◽  
Vol 56 (12) ◽  
pp. 2737-2742 ◽  
Author(s):  
Irene A. Davidova ◽  
Kathleen E. Duncan ◽  
Ok Kyoung Choi ◽  
Joseph M. Suflita

Two novel sulfate-reducing bacteria, strains ALDCT and Lake, which were able to oxidize n-alkanes, were isolated from a naval oily wastewater-storage facility (VA, USA) and from oilfield production water (OK, USA), respectively. The type strain (ALDCT) had a narrow substrate specificity and could grow only with n-alkanes (from C6 to C12), pyruvate, butyrate, hexanoic acid and 4-methyloctanoic acid. Cells of strain ALDCT stained Gram-negative and were slightly curved, short rods with oval ends (2.5–3.0×1.0–1.4 μm), often occurring in pairs. Cells tended to form aggregates or large clusters and were non-motile and did not form endospores. Optimum growth occurred between 31 and 37 °C and at pH 6.5–7.2. NaCl was not required for growth, but salt concentrations up to 55 g l−1 could be tolerated. The DNA G+C content was 53.6 mol%. Phylogenetic analysis of the 16S rRNA genes revealed that strains ALDCT and Lake were closely related, but not identical (99.9 % similarity). The two strains were not closely related to other known alkane-degrading, sulfate-reducing bacteria or to other genera of the Deltaproteobacteria. Therefore, it is proposed that strain ALDCT (=JCM 13588T=ATCC BAA-1302T) represents the type strain of a novel species and genus, with the name Desulfoglaeba alkanexedens gen. nov., sp. nov.


2001 ◽  
Vol 67 (4) ◽  
pp. 1922-1934 ◽  
Author(s):  
V. J. Orphan ◽  
K.-U. Hinrichs ◽  
W. Ussler ◽  
C. K. Paull ◽  
L. T. Taylor ◽  
...  

ABSTRACT The oxidation of methane in anoxic marine sediments is thought to be mediated by a consortium of methane-consuming archaea and sulfate-reducing bacteria. In this study, we compared results of rRNA gene (rDNA) surveys and lipid analyses of archaea and bacteria associated with methane seep sediments from several different sites on the Californian continental margin. Two distinct archaeal lineages (ANME-1 and ANME-2), peripherally related to the orderMethanosarcinales, were consistently associated with methane seep marine sediments. The same sediments contained abundant13C-depleted archaeal lipids, indicating that one or both of these archaeal groups are members of anaerobic methane-oxidizing consortia. 13C-depleted lipids and the signature 16S rDNAs for these archaeal groups were absent in nearby control sediments. Concurrent surveys of bacterial rDNAs revealed a predominance of δ-proteobacteria, in particular, close relatives ofDesulfosarcina variabilis. Biomarker analyses of the same sediments showed bacterial fatty acids with strong 13C depletion that are likely products of these sulfate-reducing bacteria. Consistent with these observations, whole-cell fluorescent in situ hybridization revealed aggregations of ANME-2 archaea and sulfate-reducing Desulfosarcina andDesulfococcus species. Additionally, the presence of abundant 13C-depleted ether lipids, presumed to be of bacterial origin but unrelated to ether lipids of members of the orderDesulfosarcinales, suggests the participation of additional bacterial groups in the methane-oxidizing process. Although theDesulfosarcinales and ANME-2 consortia appear to participate in the anaerobic oxidation of methane in marine sediments, our data suggest that other bacteria and archaea are also involved in methane oxidation in these environments.


2021 ◽  
Vol 15 (2) ◽  
pp. 35-46
Author(s):  
O. M. Сhayka ◽  
◽  
T. B. Peretyatko ◽  
A. A. Halushka ◽  

Introduction. Thermophilic sulfate-reducing bacteria attract attention of scientists as the potential agents of purification of wastewater polluted by sulfur and its compounds, heavy metal ions and organic compounds. These bacteria oxidize different organic substrates using metals with variable valency as electron acceptors and transform them into non-toxic or less toxic forms for living organisms. However, wastewater contains high concentrations of different toxic xenobiotics, particularly, metal ions that have negative influence on living organisms. For this reason, it is important to use resistant strains of microorganisms for the purification of wastewater. The aim of this work was to identify the thermophilic sulfur-reducing bacteria, isolated from “Nadiia” pit spoil heap of Chervonohrad mining region, and to study their properties. Materials and Methods. Thermophilic sulfur-reducing bacteria were isolated from the samples of rock of “Nadiia” pit heap at 50 cm depth. Bacteria were cultivated in TF medium under the anaerobic conditions in anaerostates. Cell biomass was measured turbidimetrically using the photoelectric colorimeter KFK-3 (λ = 340 nm, 3 mm cuvette). Hydrogen sulfide content was measured photoelectrocolorymetrically by the production of methylene blue. Organic acids content was measured by high performance liquid chromatography. Cr(VI), Fe(III), Мn(IV) and NO3– content was measured turbidimetrically. Results. Thermophilic sulfur-reducing bacteria were isolated from the rock of “Nadiia” pit heap of Chervonohrad mining region. They were identified as Moorela thermoacetica based on the morpho-physiological and biochemical properties and on the results of phylogenetic analysis. M. thermoacetica Nadia-3 grow in the synthetic TF medium, have the shape of elongated rods, are gram-positive, endospore-forming. They form light brown colonies. Optimal growth was observed at 50–55 °C, pH 6.5–7. The bacteria utilize glucose, starch, fructose, maltose, lactose, sodium lactate, arabinose, cellulose, maltose, glycerol, fumarate, and ethanol as carbon sources. The highest sulfidogenic activity of M. thermoacetica Nadia-3 was found in media with glycerol, lactose, and glucose. M. thermoacetica Nadia-3 reduce SO42-, S2O32-, Fe(III), NO3–, Cr(VI) compounds besides elemental sulfur. They accumulate biomass at K2Cr2O7 concentrations of 0.1–1 mM. Sulfur reduction is not the main way of energy accumulation. Conclusions. Thermophilic chromium-resistant sulfur-reducing bacteria M. thermoacetica Nadia-3, that produce hydrogen sulfide during the oxidation of different organic compounds, were isolated from the rock of “Nadiia” pit heap. They reduce Fe(III), Cr(VI), NO3–, SO42-, S2O32-, besides elemental sulfur.


2002 ◽  
Vol 48 (1) ◽  
pp. 21-33 ◽  
Author(s):  
Phillip M Fedorak ◽  
Debora L Coy ◽  
Myrna J Salloum ◽  
Marvin J Dudas

Approximately 20% of Canada's oil supply now comes from the extraction of bitumen from the oil sands deposits in northeastern Alberta. The oil sands are strip-mined, and the bitumen is typically separated from sand and clays by an alkaline hot water extraction process. The rapidly expanding oil sands industry has millions of cubic metres of tailings for disposal and large areas of land to reclaim. There are estimates that the consolidation of the mature fine tails (MFT) in the settling ponds will take about 150 years. Some of the settling ponds are now evolving microbially produced methane, a greenhouse gas. To hasten consolidation, gypsum (CaSO4·2H2O) is added to MFT, yielding materials called consolidated or composite tailings (CT). Sulfate from the gypsum has the potential to stimulate sulfate-reducing bacteria (SRB) to out-compete methanogens, thereby stopping methanogenesis. This investigation examined three MFT and four CT samples from three oil sands extractions companies. Each was found to contain methanogens and SRB. Serum bottle microcosm studies showed sulfate in the CT samples stopped methane production. However, if the microcosms were amended with readily utilizable electron donors, the sulfate was consumed, and when it reached approximately 20 mg/L, methane production began. Some unamended microcosms were incubated for 372 days, with no methane production detected. This work showed that each MFT and CT sample has the potential to become methanogenic, but in the absence of exogenous electron donors, the added sulfate can inhibit methanogenesis for a long time.Key words: consolidated tailings, composite tailings, methanogens, oil sands, sulfate-reducing bacteria.


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