Thermophilic and hyperthermophilic Archaea and Bacteria have been isolated from marine hydrothermal systems, heated sediments, continental solfataras, hot springs, water heaters, and industrial waste They catalyze a tremendous array of widely varying metabolic processes As determined in the laboratory, electron donors in thermophilic and hyperthermophilic microbial redox reactions include H2, Fe(2+), H2S, S, S2O3(2-), S4O6(2-), sulfide minerals, CH4, various mono-, di-, and hydroxy-carboxylic acids, alcohols, amino acids, and complex organic substrates; electron acceptors include O2, Fe(3+), CO2, CO, NO3(-), NO2(-), NO, N2O, SO4(2-), SO3(2-), S2O3(2-), and S Although many assimilatory and dissimilatory metabolic reactions have been identified for these groups of microorganisms, little attention has been paid to the energetics of these reactions In this review, standard molal Gibbs free energies (DeltaGr(0)) as a function of temperature to 200 degrees C are tabulated for 370 organic and inorganic redox, disproportionation, dissociation, hydrolysis, and solubility reactions directly or indirectly involved in microbial metabolism To calculate values of DeltaGr(0) for these and countless other reactions, the apparent standard molal Gibbs free energies of formation (DeltaG(0)) at temperatures to 200 degrees C are given for 307 solids, liquids, gases, and aqueous solutes It is shown that values of DeltaGr(0) for many microbially mediated reactions are highly temperature dependent, and that adopting values determined at 25 degrees C for systems at elevated temperatures introduces significant and unnecessary errors The metabolic processes considered here involve compounds that belong to the following chemical systems: H-O, H-O-N, H-O-S, H-O-N-S, H-O-C(inorganic), H-O-C, H-O-N-C, H-O-S-C, H-O-N-S-C(amino acids), H-O-S-C-metals/minerals, and H-O-P For four metabolic reactions of particular interest in thermophily and hyperthermophily (knallgas reaction, anaerobic sulfur and nitrate reduction, and autotrophic methanogenesis), values of the overall Gibbs free energy (DeltaGr) as a function of temperature are calculated for a wide range of chemical compositions likely to be present in near-surface and deep hydrothermal and geothermal systems

http://rcn.montana.edu/Resources/LRES555/Manuscripts/energetics.pdf

Energetics of overall metabolic reactions of thermophilic and hyperthermophilic Archaea and Bacteria

Dissimilatory Sulfate- and Sulfur-Reducing Prokaryotes

Although the importance of bacterial activities in oil reservoirs was recognized a long time ago, our knowledge of the nature and diversity of bacteria growing in these ecosystems is still poor, and their metabolic activities in situ largely ignored. This paper reviews our current knowledge about these bacteria and emphasises the importance of the petrochemical and geochemical characteristics in understanding their presence in such environments.

Microbiology of petroleum reservoirs.

Composting is a controlled self-heating, aerobic solid phase biodegradative process of organic materials The process comprises mesophilic and thermophilic phases involving numerous microorganisms In several successive steps, microbial communities degrade organic substrates into more stable, humified forms and inorganic products, gener- ating heat as a metabolic waste product Due to the complexity of substrates and intermedi- ate products, microbial diversity and the succession of populations is a prerequisite to ensure complete biodegradation Due to the dynamic process, both in time and space (microhabi- tats), which is reflected by constantly changing pH, humidity, oxygen partial pressure and temperature it is extremely difficult to detect, albeit isolate, all the microorganisms involved Research on composts is also so difficult because the process can hardly be simulated in the laboratory since all major gas and temperature fluxes are to a large extent determined by the physical extension of the system In this comprehensive survey of literature an inventory of the mesophilic and thermophilic bacteria, actinomycetes and fungi isolated during several phases of composting (including also self-heating organic materials) is presented

A survey of bacteria and fungi occurring during composting and self-heating processes

Bacteria of the sulphur cycle: An overview of microbiology, biokinetics and their role in petroleum and mining industries

A moderately thermophilic, facultatively anaerobic, amylolytic bacterium was isolated from palm wine, a tropical alcoholic beverage that was sampled in Senegal. The cells were gram positive, catalase positive, non-spore forming, rod shaped, and slightly motile with peritrichous flagella. The strain which we examined did not possess cytochrome and produced L-(+)-lactate, acetate, ethanol, and formate but not hydrogen during carbohydrate fermentation. Growth occurred at pH values ranging from 5.4 to 8.5, and optimum growth occurred at around pH 7.0. The optimum temperature for growth was around 50°C, and the upper temperature limit for growth was 58°C. The guanine-plus-cytosine content of the DNA was 38.8 ± 0.2 mol%. A sequence analysis of the 16S rRNA gene revealed that the new organism is closely related phylogenetically to members of genus Bacillus. Despite the lack of spores, we propose that on the basis of phylogenetic characteristics, the new isolate should be classified as a new Bacillus species, Bacillus thermoamylovorans. The type strain is strain DKP (= Collection of Institut Pasteur CNCM 1-1378).

/pdf/bacillus-thermoamylovorans-sp-nov-a-moderately-thermophilic-418v3c67k4.pdf

Bacillus thermoamylovorans sp. nov., a moderately thermophilic and amylolytic bacterium.

A thermophilic sulfate-reducing bacterium, Desulfacinum infernum, is described. This bacterium was isolated from produced formation water from a North Sea petroleum reservoir. In liquid culture, the cells are oval, 1.5 by 2.5 to 3 μm, nonmotile and gram negative. Spore formation has not been observed. Growth occurs at temperatures ranging from 40 to 65°C, with optimum growth occurring at 60°C, and at levels of salinity ranging from 0 to 50 g of NaCl per liter, with optimum growth occurring in the presence of 10 g of NaCl per liter. D. infernum grows on a range of organic acids, including formate, acetate, buryrate, and palmitate, and alcohols. D. infernum can grow autotrophically with H2. A vitamin supplement is required for growth. Sulfite and thiosulfate are used as electron acceptors. Sulfur and nitrate are not reduced. The DNA base composition is 64 mol% G+C. Phylogenetically, D. infernum clusters with members of the delta subdivision of the Proteobacteria. Its closest relatives are Syntrophobacter wolinii (level of similarity, 90.6%) and Desulfomonile tiedjei (level of similarity, 87.1%).

Desulfacinum infernum gen. nov., sp. nov., a thermophilic sulfate-reducing bacterium from a petroleum reservoir

Strain MLFT(T = type strain), a new thermophilic, spore-forming sulfate-reducing bacterium, was characterized and was found to be phenotypically, genotypically, and phylogenetically related to the genus Desulfotomaculum. This organism was isolated from a butyrate enrichment culture that had been inoculated with a mixed compost containing rice hulls and peanut shells. The optimum temperature for growth was 50°C. The G+C content of the DNA was 51.2 mol%. Strain MLFTincompletely oxidized pyruvate, butyrate, and butanol to acetate and presumably CO2. It used long-chain fatty acids and propanediols. We observed phenotypic and phylogenetic differences between strain MLFTand other thermophilic Desulfotomaculum species that also oxidize long-chain fatty acids. On the basis of our results, we propose that strain MLFTis a member of a new species, Desulfotomaculum thermosapovorans.

/pdf/isolation-and-characterization-of-a-thermophilic-sulfate-32resc8cbp.pdf

Isolation and characterization of a thermophilic sulfate-reducing bacterium, Desulfotomaculum thermosapovorans sp. nov

A new thermophilic, glucose-fermenting, anaerobic isolate, strain IndiB4T, was obtained from the nonvolcanically heated waters of an Indian artesian basin bore and was named Caloramator indicus. The cells of this organism were rod shaped to filamentous and occurred singly, in pairs, or in short chains. Motility and spores were not observed. Electron micrographs of thin sections revealed a typical gram-positive cell wall structure, although the cells stained gram negative. The optimum temperature for growth was 60 to 65°C, the maximum temperature was 75°C, and the minimum temperature was more than 37°C. Growth occurred at pH values between 6.2 and 9.2, and the optimum pH was between 7.5 and 8.1. The generation time of C. indicus at the optimal temperature and optimal pH was 20 min. The DNA base composition was 25.6 ± 0.3 mol% guanine plus cytosine as determined by thermal denaturation. Strain IndiB4T utilized a wide range of carbohydrates, including starch, amylopectin, sucrose, mannose, lactose, fructose, and cellobiose. Ethanol, acetate, lactate, CO2, and H2 were the end products of glucose fermentation. Growth was inhibited by pencillin, tetracycline, and chloramphenicol, indicating that the organism is a member of the domain Bacteria. A phylogenetic analysis of the 16S rRNA gene revealed that strain IndiB4T is affiliated with the low-guanine-plus-cytosine-content subgroup of the gram-positive phylum. The type strain of C. indicus is strain IndiB4 (= ACM 3982).

Caloramator indicus sp. nov., a New Thermophilic Anaerobic Bacterium Isolated from the Deep-Seated Nonvolcanically Heated Waters of an Indian Artesian Aquifer

A method for DNA sequencing of ribosomal RNA (rRNA) genes, amplified by polymerase chain reaction (PCR), using internal primers, designed on the basis of conserved regions of rRNA genes for determining a near complete sequence (99%) of the gene using an automated DNA sequencer (Applied Biosystem Incorporation, USA) is described. The procedure is extremely rapid as cloning of the gene is not required for sequence determination. In addition time consuming steps such as ethanol precipitation and hazardous steps such as phenol/chloroform extractions are excluded from the protocol for the purification of extension products after Taq cycle sequencing using the ABI dye terminator chemistry. The method has been successfully used for sequencing of the 16S and 18S rRNA genes of microbes which includes six members of domain Bacteria, one of domain Archaea and one belonging to Eukarya domain.

/pdf/a-rapid-method-for-sequencing-of-rrna-gene-s-amplified-by-2sblrknnve.pdf

Prem P. Dwivedi

Papers

Bacillus thermoamylovorans sp. nov., a moderately thermophilic and amylolytic bacterium.

Desulfacinum infernum gen. nov., sp. nov., a thermophilic sulfate-reducing bacterium from a petroleum reservoir

Isolation and characterization of a thermophilic sulfate-reducing bacterium, Desulfotomaculum thermosapovorans sp. nov

Caloramator indicus sp. nov., a New Thermophilic Anaerobic Bacterium Isolated from the Deep-Seated Nonvolcanically Heated Waters of an Indian Artesian Aquifer

A rapid method for sequencing of rRNA gene(s) amplified by polymerase chain reaction using an automated DNA sequencer