Thioglucosidase activity from Sphingobacterium sp strain OTG1

Screening for novel thioglucoside hydrolase activity resulted in the isolat ion of Sphingobacterium sp. strain OTG1 from enrichment cultures containing octylthioglucoside (OTG). OTG was hydrolysed into octanethiol and glucose by cell free extracts. Besides thioglucoside hydrolysis, several other gluc oside hydrolase activities were detected in the Sphingobacterium sp. strain OTG I cell free extract. By adding beta -glucosidase inhibitors it was pos sible to discriminate between these different activities. Ascorbic acid and D-gluconic acid lactone inhibited the hydrolysis of p-nitrophenyl beta -gl ucoside, but did not affect octyl- and octylthioglucoside hydrolase activit y. Besides OTG, various other thioglucosides were hydrolysed by the novel t hioglucosidase. with almost the same activities regardless of the nature of the aglycone, including the myrosinase model substrate sinigrin (a glucosi nolate). Sinigrin could also be used as a growth substrate by Sphingobacter ium sp. strain OTG1, although at concentrations exceeding 0.15 mM degradati on was not complete.