Local Isolate of Bacillus stearothermophilus Producing Alkaline Phosphatase Activity by two Fermentation Systems

Abstract

From soil samples in different region of Iraqi-Kurdistan, thirty-one isolates of
Bacillus spp. were isolated and identified in all samples according to morphology of
colonies, cells and their growth at 55°c. Using high temperature 75°c and some
biochemical tests, only seven isolates were diagnosed as B. stearothermophilus.
The isolate no. 18 was selected based on its high activity of enzymes (amylases &
proteases). Using two fermentation systems (liquid state & solid state fermentation),
the isolate no.18 was examined for production of alkaline phosphatase (AP) enzyme
activity. The liquid state fermentation method for this isolate gave a 4.9 un it/ml
enzyme activity at optimum pH and 5.8 unit/mg protein specific activity, whereas the
solid state fermentation (wheat bran) gave 11.32 unit/ml enzyme activity and 7.48
unit/mg protein specific activity.
Results revealed high activity of alkaline phosphatase screening from local isolate
of Bacillus stearothermophilus using wheat bran in solid state fermentation.