Thermophilic strains

Another thermophilic strain M. phlei WU-0103 was discovered by the Ishii group and reported to be capable of desulfurization of DBT, NTH, and BT and their... 

A thermophilic strain M. goodii X7B was reported to carry out desulfurization of BT and DBT [38], The growth of the strain on various sulfur substrates including DBT, BT, 4,6-dimethyl DBT, 5-methyl BT, 2-thiophene carboxylic acid and propylmercaptan was studied at 45°C and varying degree of growth was observed. A mechanism of sulfur removal was proposed for BT based on metabolites identified by GC-MS (Fig. 7 [125]). 

The enzyme BdsC from the thermophilic strain B. subtilis WU-S2B has also been isolated [150], This enzyme has a subunit MW of 45kDa and a native molecular mass of 200 kDa. It has a temperature optimum of 50°C and a pH optimum of 8.0. Its stability at this temperature was 80% after incubation for 30 min. This enzyme demonstrated inhibition characteristics similar to other DBT monooxygenases, indicating involvement of metal ions and cysteine/SH groups in catalytic activity. 

A strain of thermophilic Acetobacter was patented in Japan for oxidizing ethanol in a submeiged culture oxidizer at temperatures as high as 37°C with considerable savings in cooling water. Another thermophilic strain of Acetobacter maintained full activity at 35°C, and 45% of its maximum activity at 38°C. 

Efforts for the isolation or genetic manipulation of ethanol-resistant strains, which are less sensitive to alcohol inhibition 19), are being made. The selection of thermotolerant and thermophilic strains is feasible 20). 

Methanogenic bacteria contain high internal concentrations, ranging from 150mM in some mesophilic strains, to about 1 M in some thermophilic strains, up to 3 M in the extreme thermophile A/et/ianopiyru [22,175,265,266]. The anion of in thermophilic methanogens is the trianionic cyclic 2,3-diphosphoglycerate [266-268] this... 

To analyze the subtle specific structural features of thermophilic archaeal proteins, comparisons with closely related mesophilic proteins are necessary. Since the Crenarchaeota comprise exclusively thermophilic strains, respective comparisons are only possible with proteins from Euryarchaeota. Structural comparisons between thermophilic archaeal proteins and mesophilic bacterial or eucaryal proteins are unlikely to be useful because of the large evolutionary distance between different domains, which blur the thermoadaptive features. 

Ohmomo S, Kaneko M, Atthasampunna P (1989) Production of Fumigaclavine B by a Thermophilic Strain of Aspergillus fumigatus. World J Microbiol Biotechnol 5 5... 

Synthetic medium + thermophilic strain T. fusca, 21 days,55°C... 

Ohmomo, S., Kaneko, M. and Atthasampunna, P. (1989) Production of fumigaclavine B by a thermophilic strain of Aspergillus fumigatus. Mircen 5, 5-13. 

A thermophilic strain capable of degrading PA-12 was isolated from 100 soil samples using an enrichment culture technique at 60 °C. At this temperature, the strain not only grew on PA-12, but also reduced the molecular weight of the polymer. The strain was identified as a neighbouring species to Bacillus pallidus it has an optimum growth temperature of around 60 °C and was also found to degrade PA-6 as well as PA-12, but not PA-66 [52]. 

SRBs reduce sulfate to sulfide, which usually shows up as hydrogen sulfide or, if iron is available, as black ferrous sulfide (Fig. 10.10). In the absence of sulfate, some strains can function as fermenters and use organic compounds such as pyruvate to produce acetate, hydrogen, and carbon dioxide. Many SRB strains also contain hydrogenase enzymes, which allow them to consume hydrogen. Most common strains of SRB grow best at temperatures from 25 to 35°C. A few thermophilic strains capable of functioning efficiently at more than 60°C have been reported. 

Wittiich P, Themann A, Vorlop K-D (2001) Conversion of glyarol to 1,3-propanediol by a newly isolated thermophilic strain. Biotechnol Lett... 

Rai, S. K., Roy, J. K., Mukherjee, A. K. Characterization of a detergent-stable alkaline protease from a novel thermophilic strain Paenibacillus tezpurensis sp. nov. AS-S24-II. Appl Microbiol Biotechnol 2010, 85(5), 1437-1450. 

The other bottleneck for lactic acid production is the operating cost. For example, sterilization is necessary for fermentative production. Hence, microorganisms have an optimal fermentation temperature between 30 2°C (John et al., 2007). Therefore it is difficult to avoid contamination if the medium is not sterilized. Qin et al. (2009) have reported the use of a newly isolated thermophilic strain. Bacillus sp. strain 2 to 6, for the unsterilized fermentative production of L-lactic acid. A high yield (97.3%), productivity (4.37g/L/h), and optical purity of L-lactic acid (99.4%) were obtained in batch and fed-batch open fermentations (Qin et al., 2009). This will help to reduce energy consumption and lower labor costs. Moreover, because of the inhibitory effects of a low pH on cell growth and lactic acid production, CaCOs must be added to maintain a constant pH as a consequence, the regeneration of precipitated calcium lactate is observed (Datta and Henry, 2006). To solve this problem, a sodium lactate-tolerant strain. Bacillus sp. Na-2, was obtained by ion-beam implantation and applied during an L-lactic acid production process (Qin et al., 2010). On the other hand, new processes can be applied to prevent the production of calcium lactate, for example, reverse osmosis, ultrafiltration, electrodialysis, and solvent extraction (Datta and Henry, 2006). 

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