EFFECT OF DIFFERENT STARCHES ON ESCHERICHIA-COLI (S1) BETA-GLUCURONIDASE EXPRESSION

Studies with pure cultures growing in laboratory media indicated that beta-glucuronidase expression of Escherichia coli SL was considerably affected by starch added to the medium as the only carbon source. This result, which may be an aspecific modulation of enzyme expression, wa s independent of the starch molecular structure and effects were analo gous for maize, rice, wheat or potato starches. It was observed that e nzyme expression was little affected by the growth rate. The beta-gluc uronidase activities of starch-grown bacteria found in the present stu dy agree with those observed in animal and human models performed for in vivo evaluation of effects of dietary starch effects on gut microbi al ecosystems.