Isolation and Screening of Bacillus subtilis from Soil for Amylase Production

Abstract

This study was aimed at isolating Bacillus subtilis from soil and screening the isolates for amylase production. A total of fifteen (15) soil samples, five each from botanical garden, refuse dump sites, and flower beds were collected and subjected to cultural isolation followed by biochemical and microgen identification. The isolates of B. subtilis were then screened for amylase production using the starch agar plate method. Nine (9) isolates were confirmed to be Bacillus subtilis with a percentage occurrence of 80% from refuse dump sites and botanical garden and 20% from flower beds. All the B. subtilis isolates demonstrated amylase production ability, with isolate RD4 from refuse dump sites having the highest diameter of the zone of starch hydrolysis (29mm). Bacillus subtilis can readily be isolated from various soil types with a frequency of 80% in soils from gardens and refuse dumps and 20% from flower beds. All the B. subtilis isolates demonstrated the potential for amylase production. This preliminary study could provide information on the isolation of B. subtilis from various soil types for the production of amylase.