ISOLATION OF BIOTECHNOLOGICALLY IMPORTANT ENZYME PRODUCING RHIZOBACTERIA FROM SEASONAL FLOWER BEDS

Abstract

This study aimed to isolate biotechnologically important enzyme like amylase
and protease producing rhizobacteria from rhizospheric soil. Soil samples were
collected from the rhizospherc of five different flowering plants from Curzon hall,
University of Dhaka. A good number of bacteria were isolated. Among them 12
bacterial isolates were selected for detailed study based on their amylolytic and
proteolytic activity. Starch hydrolysis ratio (SHR) of the studied isolates ranged in
between 2.06 and 4.67, casein hydrolysis ratio (CHR) ranged in between 2.27 and
3.92. All the selected isolateswere Gram positive and rod shaped and provisionally
identified as the member of the genus Bacillus with five different species viz. Bacillus
alcalophilus, B. subtilis, B. pumilus, B. firmus and B. lentus. Amylase and protease
production of the studied bacteria were estimated and it was ranged in between
29.11±9.57 to 35.78 ± 9.05 and 230.27±37.08 to 276.47 ± 55.01 U/ml. The highest
amylase and protease producer were Bacillus alcalophilus (Ce104/S9/L) which could
produce 35.78 ± 9.05 U/ml and Bacillus subtilis (Ca71/S5/L) could produce 276.47
± 55.01 U/ml of protease, respectively. Maximum production of both amylase and
protease was achieved in 24 h of incubation period at 37°C and pH 7.0.