Abstract

L-Asparaginase is a well know enzyme for its antineoplastic potential and is widely used to treat acute lymphoblastic leukemia and lymphosarcoma. The present work describes the isolation and characterization of novel L-asparaginase producing Bacillus strains from soil. Soil samples were collected from three different locations such as fruit garden, dairy farm and agricultural land in Peshawar Khyber Pakhtunkhwa, Pakistan. The isolates were screened to produce L-asparaginase in growth medium supplemented with 1% L-asparagine using a phenol red indicator. Among 30 bacterial isolates, only two strains initially coded as A5 and FG7 showed L-asparaginase activity. Based on biochemical and 16S rRNA sequencing analysis, the isolate A5 and FG7 were identified as Bacillus amyloliquefaciens and Bacillus proteolyticus respectively. Different factors like pH and time were optimized for maximum L-asparaginase activity. Bacillus amyloliquefaciens showed maximum asparaginase activity at pH 7 after 24 hours incubation at 30oC, while Bacillus proteolyticus showed optimum activity at pH 7 after 48 hours of incubation at 30oC. The present study first time reported the production of L-asparginase enzyme from Bacillus amyloliquefaciens and Bacillus proteolyticus.

Keywords: L-asparaginase, Bacillusamyloliquefaciens, Bacillus proteolyticus, 16sRNA.