Isolation and Characterization of Bacteria Which Produce α-Xylosidase and Cultural Conditions for Enzyme Production

Abstract

Two strains of Bacillus species capable of producing α-d-xylosidase were isolated from soil samples by a novel method using glucose oxidase. They were facultatively anaerobic, gram-negative, and mesophilic, and formed ellipsoidal, central/terminal endospores. The guanine + cytosine content of the DNA were 50.8 mol% for strain No. 208-918-1 and 44.5 mol% for strain No. 693-1. The profiles of physiological and biochemical features of both strains were almost identical and differed from those of the previously described species of Bacillus. It was found that α-d-xylosidase of strain No. 693-1 was a typical inducible enzyme induced by methyl α-d-xyloside and isopropyl α-d-xyloside. The optimum conditions for the production of α-d-xylosidase were found to be a 1:1 ratio of glucose/peptone and an inducer concentration (methyl α-d-xyloside) of 1.0% in the medium. Moreover, the addition of CaCl₂ into the medium enhanced α-d-xylosidase production.