Expression and biochemical characterization of a multifunctional glycosidase from the thermophilic Bacillus licheniformis SR01

Yang-dao Wei, Ya Li, Chun Deng, Shi-hua Wu, Cui-ji Huang, Yi Yi
2017 Journal of General and Applied Microbiology  
A gene (gkdA) (741 bp) encoding a putative protein of 247 amino acids was cloned from the Bacillus licheniformis SR01. The protein was expressed in Escherichia coli BL21 with a molecular mass estimated by SDS-PAGE of approximately 28.03 kDa and showed a calculating isoelectric point (pI) of 6.42. Structure analysis and function identification showed that the enzyme was a multifunctional glycosidase. Its specific activity was 0.013 U/m m m m mg. The recombinant glycosidase showed a maximum
more » ... ty at 50∞C and pH 7.0. It was very stable below 90∞C and may have heat activation at higher temperatures. The relative residual activity was still more than 80% after 120 min at pH 5.0-10.0. The enzyme activity was inhibited by Cu 2+ , Fe 2+ , Ca 2+ , Mg 2+ , Co 2+ , Li + , SDS and EDTA, activated by Ca 2+ , and not affected by Mn 2+ and K + . Under simulated stomach, and in vitro intestine, conditions, the enzyme retained 80%, and more than 100%, activity, respectively, after incubation for 90 min. The excellent properties of this enzyme, specifically its thermal stability and multifunctional abilities, give it potential application in the field of feed processing and other high-temperature processing industries.
doi:10.2323/jgam.2016.12.001 pmid:28835594 fatcat:idddyf3kcfc3jbwhexkolesnmu