Screening for starch-hydrolysing bacteria

ABSTRACT

Screening of 3000 soil samples collected from cities of four different provinces of Iran for starch-hydrolysing bacteria revealed that the nature is enriched with Streptomyces species capable of producing amylolytic enzymes. Among the bacterial isolates, one of the high starch degrading strains was selected for further microbiological identification and also amylolytic enzyme[s] characterization. The purified isolate, streptomyces species strain RY48,produces almost four times more amylolytic enzyme[s] than Bacillus subtilis [PTCC1254]on agar plates. Based on the action pattern of its amylolytic enzymes on the boiled maize starch, the purified species possesses in the logphase an amylolytic activity which is different from the amylolytic activity of the stationary phase. The secreted amylolytic enzymes which are both endolytic type and show different activity bands on native polyacrylamide gel, act independently on starch molecules