The serine alkaline protease, SAPB, from Bacillus pumilus CBS is an effective additive in laundry detergent formulations (Jaouadi et al., 2008). Twelve mutants of SAPB have constructed by site-directed mutagenesis and the results demonstrate that all the amino acids of the catalytic cluster and amino acids intimately related to the hydrophobic environments near the active site are important for engineering of kinetic performances of detergent-stable enzymes (Jaouadi et al., 2010). Mutations outside of the catalytic centre or the binding sites resulted in increased catalytic activity of the enzyme, as has been observed in other studies

(van der Veen et al., 2004; Fan et al., 2007). For the rational enzymatic design, the amino acid residues that are close to the active

centre or the binding pocket are often modified. click here However, the amino acid residues that are located far from these two places may play an important role in enzymatic function. Random mutagenesis can be introduced into gene sequences when it is not necessary to know the identity of the structure–function relationship of the enzyme. Currently, whether nattokinase may become a widely used thrombolytic agent mainly selleck chemical depends on the enhancement of its properties, e.g. prolonging the half-life with oral administration and improving the stability and catalytic efficiency. In conclusion, the results of our work have demonstrated that it is feasible to generate a mutant library of nattokinase using the DNA family shuffling method to obtain a mutant with enhanced catalytic efficiency. With better catalytic efficiency, the mutant may become a desirable

and economical source for use in thrombolytic therapy or other industrial applications. Further investigation of the selection of mutants with high catalytic efficiency using the DNA family shuffling and screening method is promising. The authors selleck inhibitor sincerely thank Dr. Yufeng Zhao from the Wuhan Institute of Technology for critical reading of the manuscript. This work was funded by grants from the National Natural Science Foundation of China (Nos. 30670464, 20873092, 30800190), National Mega Project on Major Drug Development (No. 2009ZX09301-014-1) and Science and Technology Project of Wuhan (No. 200960323115). “
“Rhizoctonia solani is an important soilborne pathogen of potato plants whose control typically depends on chemicals. Here, we screened six fungal endophytes for the suppression of R. solani growth both in vitro and in a greenhouse. These isolates were identified using morphology and internal transcribed spacer regions of rDNA as Alternaria longipes, Epicoccum nigrum, Phomopsis sp., and Trichoderma atroviride. Both T. atroviride and E. nigrum showed significant in vitro inhibition of mycelial growth of R. solani, with the greatest inhibition zone observed for E. nigrum species in dual cultures. The highest inhibition was observed for T. atroviride.