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The acidophilic and thermophilic cellulase would facilitate the conversion of lignocellulosic biomass to biofuel. In this study, Bacillus sonorensis HSC7 isolated as the best thermophilic cellulose degrading bacterium from Gorooh hot spring. 16S rRNA gene sequencing showed that, this strain closely related to the B. sonorensis. CMCase production was considered under varying environmental parameters. Results showed that, sucrose and (NH4)2SO4 were obtained as the best carbon and nitrogen sources for CMCase production. B. sonorensis HSC7 produced CMCase during the growth in optimized medium supplemented with agricultural wastes as sole carbon sources. The enzyme was active with optimum temperature of 70 °C and the optimum CMCase activity and stability observed at pH 4.0 and 5.0, respectively. These are characteristics indicating that, this enzyme could be an acidophilic and thermophilic CMCase. Furthermore, the CMCase activity improved by methanol (166%), chloroform (152%), while it was inhibited by DMF (61%). The CMCase activity was enhanced in the presence of Mg+2 (110%), Cu+2 (116%), Triton X-100 (118%) and it retained 57% of its activity at 30% NaCl. The compatibility of HSC7 CMCase varied for each laundry detergent, with higher stability being observed in the presence of Taj® and darya®. This enzyme, that is able to work under extreme conditions, has potential applications in various industries.

Nitrile-hydrolyzing bacteria have the potential to perform useful biotransformations such as the production of industrially useful acids and amides. In this study, we report a nitrile-degrading bacterium with signifi cant nitrile metabolism. Molecular characterization of 16S rDNA gene characterized this strain as Bacillus cereus . Medium optimization of B. cereus FA12 showed that biomass and nitrilase production was strongly supported by glucose (10 gL Ϫ 1 ) and yeast extract (10 gL Ϫ 1 ). Enzymatic production improved slightly in the pH range from 6.0 to 7.0. The addition of Mg ϩ 2 , Fe ϩ 2 , and Na ϩ supported biomass and nitrilase production; however, other metal ions, Co ϩ 2 and Cu ϩ 2 , inhibited production. The apparent molecular mass of the puri fi ed FA12 nitrilase as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was about 45 kDa. Nitrilase FA12 shows relatively high activity and stability at pH 7.0 and 40 ° C. Nitrilase FA12 was marginally inhibited with Ca ϩ 2 and Co ϩ 2 , whereas inhibition in the presence of dithiothreitol or DTT was 80%. The pseudo K m (mM) values of resting cells (i.e., treating whole cells as if they were an enzyme) for acetonitrile and acetamide were determined to be 2.36 and 1.81, respectively. Under optimum situations, B. cereus FA12 resting cells produced 83 and 58 (U/mg) acetonitrile/acetamide degrading activity, respectively. Ammonia production from acetamide and acetonitrile by the B. cereus FA12 was maximum after 5 and 7 h of incubation, respectively. These results indicate that B. cereus FA12 resting cells may be used in nitrile biotransformations to produce commercially useful compounds.