Thermophiles moderate

Srivastava [434,435], The process can be carried out under aerobic (KSARC56) or anaerobic conditions (Mic-1). The identified products include methane, lower alcohols, volatile fatty acids, and/or humic acid. For aromatic feeds the main products are phenols (and derivatives), methane and carbon dioxide. The process is carried out in a slurry phase, at pH of 7.8, under moderate stirring using a bacteria concentration less than 20%. The feed concentration could not exceed more than 50%, as stated in the patent document. In the aerobic operation, the thermophilic consortium KSARC56 is operated for 48 hours at a temperature of up to about 60°C. For the anaerobic operation a mixture of N2 C02 of about 80 20 was used. 

Kayser, K. J. Cleveland, L. Park, H. S., et al., Isolation and Characterization of a Moderate Thermophile, Mycobacterium Phlei GTIS10, Capable of Dibenzothiophene Desulfurization. Applied Microbiology and Biotechnology, 2002. 59(6) pp. 737-745. 

Kirimura, K. Furuya, T. Nishii, Y., et al., Biodesulfurization of Dibenzothiophene and Its Derivatives Through the Selective Cleavage of Carbon-Sulfur Bonds by a Moderately Thermophilic Bacterium Bacillus Subtilis WU-S2B. Journal of Bioscience and Bioengineering, 2001. 91(3) pp. 262-266. 

Bonch-Osmolovskaya EA, Miroshnichenko ML, Chernyh NA, et al. 1997. Reduction of elemental sulfur by moderately thermophilic organotrophic bacteria and description of Thermoanaerobacter sulfurophilus sp. nov. Microbiology 66 483-9. 

Bridge TAM, Johnson DB. 1998. Reduction of soluble iron and reductive dissolution of ferric iron containing minerals by moderately thermophilic iron-oxidizing bacteria. Appl Environ Microbiol 64 2181-6. 

Wiegel J, Kuk S, Kohring GW. 1989. Clostridium thermobutyricum sp. nov., a moderate thermophile isolated from a cellulolytic culture, that produces butyrate as the major product. Int J Syst Bacteriol 39 199-204. 

Dimise EJ, Widboom PF, Bruner SD (2008) Structure Elucidation and Biosynthesis of Fuscachelins, Peptide Siderophores from the Moderate Thermophile Thermobifida fusca. Proc Natl Acad Sci USA 105 15311... 

Some good hints to help answer this question have been obtained by studying thermophilic proteins which are in turn obtained from thermophilic organisms. The optimum growth temperature for thermophilic organisms is between 40° and 65°C (moderate thermophiles) and 70° and 105°C (extreme thermophiles). Their respective enzymes have catalytically indistinguishable reactivity and catalytic sites from those isolated from mesophilic organisms. 

Although assays based on the retention of room temperature activity after heat treatment are convenient, the constraints imposed during the laboratory evolution can be quite different Ifom anything an enzyme in a natural thermophilic organism might have encountered. Retaining activity at moderate temperatures is probably not relevant for enzymes... 

Szilagyi A, Zavodszky P. Structural differences between meso- 25. philic, moderately thermophilic and extremely thermophilic protein subunits results of a comprehensive snrvey. Stmcture 2000 8 493-504. 26. 

The observation that the fatty acid synthetase (FAS) in H. cutirubrum is strongly inhibited by high salt concentration while the mevalonate enzyme system for isoprenoid biosynthesis has an absolute requirement for high salt concentration (see section 4.1) may offer a clue to the mechanism of evolution of extreme halophiles from non-halophilic, or moderately halophilic precursors, and possibly also for the evolution of the methanogens and extreme thermophiles. The following hypothetical scenarios are offered for discussion (see ref [107] and Figs. 9, 14) ... 

Data are from references [89,91,92] and from Mikulik (personal communication) for Calderobacterium hydrogenophilum. Reverse gyrase activity has not been detected in moderately thermophilic and mesophilic eubacteria from the genera Bacillus and Thermus [89]. In all cells lacking reverse gyrase activity, except Halobacterium halobium, one can detect an ATP-independent relaxation activity. 

The habitats available were disparate. Examples include hydrothermal high-tempera-ture (>85 °C) settings moderate thermophile settings (—40 °C) on the fringes of hot areas, or in cooler, probably more alkaline springs very cool (—0 °C) water distal to hydrothermal vents but in the flux of metals and geochemical contrasts from hydrothermal plumes in tidal waters where... 

Thermophile High temperature Moderate thermophiles (45-65°C) Thermophiles (65-85°C) Hyperthermophiles (>85°C) Amylases, xylanases Proteases, DNA polymerases Methanobacterium, Thermoplasma, Thermus, some Bacillus species, Aquifes, Archaec lobus, Hydrogenobacter, Methanothermus, Pyrococcus, Pyrodictium, Pyrolobus, Sulfolobus, Thermococcus, Thermoproteus, Thermotoga ... 

Isolation and Properties of Some Mesophii.es and Moderate Thermophile.s... 

Moderately thermophilic bacteria, those with an optimum temperature for growth of between 45 and 50°C, have been isolated from a variety of sites, such as mud springs, coal piles, various mineral dumps, and drainage waters from sulfide ore deposits, dumps, and mines (22). Some examples are listed in Table I. Mixed bacterial cultures isolated from such environments have been purified by serial dilution and plating on thiosulfate or tetrathionate agar (83). Some moderate thermophiles are active over a wide temperature range. A mixed culture oxidized pyrite at 30°C as rapidly as T. ferrooxidans alone and carried out the same reactions at temperatures over 50°C (6). These properties are of considerable value in commercial operations (Section V). 

Moderate thermophiles are heterogeneous in genotype, with the G + C content of their DNA spanning the range 47.2-68.5 mol% (Table I), showing that they must be classified in different genera. Moderately thermophilic cultures examined by Harrison (46) contained appreciable amounts of 4-methyl and 5-methylcytidine derivatives in their DNA, which may aid in their identification. 

Table II shows that moderately thermophilic bacteria display considerable variation in size. For comparison. Table II also includes details of the mesophile Thiobacillus ferrooxidans. The gram-negative moderate thermophiles designated TH vary in size (1-6 pm long by 0.5-0.8 /xm wide). Strain THl grown on Fe(II) and yeast extract has cell dimensions of about 6 by 0.8 pm, but are generally smaller when grown...

Sizes of Moderately Thermophilic Bacteria and Thiobacillus ferrooxidans ... 

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