@article {1708, title = {Hydrogen Production and Enzyme Activities in the Hyperthermophile Thermococcus paralvinellae Grown on Maltose, Tryptone, and Agricultural Waste.}, journal = {Front Microbiol}, volume = {7}, year = {2016}, month = {2016}, pages = {167}, abstract = {

Thermococcus may be an important alternative source of H2 in the hot subseafloor in otherwise low H2 environments such as some hydrothermal vents and oil reservoirs. It may also be useful in industry for rapid agricultural waste treatment and concomitant H2 production. Thermococcus paralvinellae grown at 82{\textdegree}C without sulfur produced up to 5 mmol of H2 L(-1) at rates of 5-36 fmol H2 cell(-1) h(-1) on 0.5\% (wt vol(-1)) maltose, 0.5\% (wt vol(-1)) tryptone, and 0.5\% maltose + 0.05\% tryptone media. Two potentially inhibiting conditions, the presence of 10 mM acetate and low pH (pH 5) in maltose-only medium, did not significantly affect growth or H2 production. Growth rates, H2 production rates, and cell yields based on H2 production were the same as those for Pyrococcus furiosus grown at 95{\textdegree}C on the same media for comparison. Acetate, butyrate, succinate, isovalerate, and formate were also detected as end products. After 100 h, T. paralvinellae produced up to 5 mmol of H2 L(-1) of medium when grown on up to 70\% (vol vol(-1)) waste milk from cows undergoing treatment for mastitis with the bacterial antibiotic Ceftiofur and from untreated cows. The amount of H2 produced by T. paralvinellae increased with increasing waste concentrations, but decreased in P. furiosus cultures supplemented with waste milk above 1\% concentration. All mesophilic bacteria from the waste milk that grew on Luria Bertani, Sheep{\textquoteright}s Blood (selective for Staphylococcus, the typical cause of mastitis), and MacConkey (selective for Gram-negative enteric bacteria) agar plates were killed by heat during incubation at 82{\textdegree}C. Ceftiofur, which is heat labile, was below the detection limit following incubation at 82{\textdegree}C. T. paralvinellae also produced up to 6 mmol of H2 L(-1) of medium when grown on 0.1-10\% (wt vol(-1)) spent brewery grain while P. furiosus produced < 1 mmol of H2 L(-1). Twelve of 13 enzyme activities in T. paralvinellae showed significant (p < 0.05) differences across six different growth conditions; however, methyl viologen-dependent membrane hydrogenase activity remained constant across all media types. The results demonstrate the potential of at least some Thermococcus species to produce H2 if protein and α-glucosides are present as substrates.

}, issn = {1664-302X}, doi = {10.3389/fmicb.2016.00167}, author = {Hensley, Sarah A and Moreira, Emily and Holden, James F} } @article {1200, title = {Complete genome sequence of hyperthermophilic archaeon Thermococcus sp. ES1.}, journal = {J Biotechnol}, volume = {174C}, year = {2014}, month = {2014 Jan 25}, pages = {14-15}, abstract = {

Thermococcus sp. strain ES1 is an anaerobic, hyperthermophilic archaeon from a hydrothermal vent that catabolizes sugars and peptides and produces H2S from S{\textdegree}, H2, acetate and CO2 as its primary metabolites. We present the complete genome sequence of this strain (1,957,742bp) with a focus on its substrate utilization and metabolite production capabilities. The sequence will contribute to the development of heterotrophic archaea for bioenergy production and biogeochemical modeling in hydrothermal environments.

}, issn = {1873-4863}, doi = {10.1016/j.jbiotec.2014.01.022}, author = {Jung, Jong-Hyun and Kim, You-Tae and Jeon, Eun-Jung and Seo, Dong-Ho and Hensley, Sarah A and Holden, James F and Lee, Ju-Hoon and Park, Cheon-Seok} } @article {1410, title = {Thermococcus paralvinellae sp. nov. and Thermococcus cleftensis sp. nov. of hyperthermophilic heterotrophs from deep-sea hydrothermal vents.}, journal = {Int J Syst Evol Microbiol}, volume = {64}, year = {2014}, month = {2014 Nov}, pages = {3655-9}, abstract = {

Two heterotrophic hyperthermophilic strains, ES1(T) and CL1(T), were isolated from Paralvinella sp. polychaete worms collected from active hydrothermal vent chimneys in the north-eastern Pacific Ocean. Both were obligately anaerobic and produced H2S in the presence of elemental sulfur and H2. Complete genome sequences are available for both strains. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strains are more than 97\% similar to most other species of the genus Thermococcus. Therefore, overall genome relatedness index analyses were performed to establish that these strains are novel species. For each analysis, strain ES1(T) was determined to be most similar to Thermococcus barophilus MP(T), while strain CL1(T) was determined to be most similar to Thermococcus sp. 4557. The average nucleotide identity scores for these strains were 84\% for strain ES1(T) and 81\% for strain CL1(T), genome-to-genome direct comparison scores were 23\% for strain ES1(T) and 47\% for strain CL1(T), and the species identification scores were 89\% for strain ES1(T) and 88\% for strain CL1(T). For each analysis, strains ES1(T) and CL1(T) were below the species delineation cut-off. Therefore, based on their whole genome sequences, strains ES1(T) and CL1(T) are suggested to represent novel species of the genus Thermococcus for which the names Thermococcus paralvinellae sp. nov. and Thermococcus cleftensis sp. nov. are proposed, respectively. The type strains are ES1(T) ( =DSM 27261(T) =KACC 17923(T)) and CL1(T) ( =DSM 27260(T) =KACC 17922(T)).

}, keywords = {Animals, DNA, Archaeal, Hydrothermal Vents, Molecular Sequence Data, Pacific Ocean, Phylogeny, Polychaeta, RNA, Ribosomal, 16S, Sequence Analysis, DNA, Thermococcus}, issn = {1466-5034}, doi = {10.1099/ijs.0.066100-0}, author = {Hensley, Sarah A and Jung, Jong-Hyun and Park, Cheon-Seok and Holden, James F} } @article {424, title = {Electrosynthesis of organic compounds from carbon dioxide is catalyzed by a diversity of acetogenic microorganisms.}, journal = {Appl Environ Microbiol}, volume = {77}, year = {2011}, month = {2011 May}, pages = {2882-6}, abstract = {Microbial electrosynthesis, a process in which microorganisms use electrons derived from electrodes to reduce carbon dioxide to multicarbon, extracellular organic compounds, is a potential strategy for capturing electrical energy in carbon-carbon bonds of readily stored and easily distributed products, such as transportation fuels. To date, only one organism, the acetogen Sporomusa ovata, has been shown to be capable of electrosynthesis. The purpose of this study was to determine if a wider range of microorganisms is capable of this process. Several other acetogenic bacteria, including two other Sporomusa species, Clostridium ljungdahlii, Clostridium aceticum, and Moorella thermoacetica, consumed current with the production of organic acids. In general acetate was the primary product, but 2-oxobutyrate and formate also were formed, with 2-oxobutyrate being the predominant identified product of electrosynthesis by C. aceticum. S. sphaeroides, C. ljungdahlii, and M. thermoacetica had high (>80\%) efficiencies of electrons consumed and recovered in identified products. The acetogen Acetobacterium woodii was unable to consume current. These results expand the known range of microorganisms capable of electrosynthesis, providing multiple options for the further optimization of this process.}, keywords = {Acetobacterium, Carbon Dioxide, Clostridium, Electrodes, Electrons, Moorella, Organic Chemicals, Oxidation-Reduction, Veillonellaceae}, issn = {1098-5336}, doi = {10.1128/AEM.02642-10}, author = {Nevin, Kelly P and Hensley, Sarah A and Franks, Ashley E and Summers, Zarath M and Ou, Jianhong and Woodard, Trevor L and Snoeyenbos-West, Oona L and Lovley, Derek R} }