Statistical optimization of asparaginase production by a novel isolated bacterium Brevibacillus borstelensis ML12 using Plackett–Burman design and response surface methodology

Asparaginase is widely used in food processing and pharmaceutical industries. It is produced by different types of microorganisms. Applications of this enzyme depend on its source and nature. Furthermore, economic viability depends on enzyme production by fermentation process. There is a need to search potent new microbial strains for higher asparaginase production. In this study, a potent bacterial strain was isolated from different soil samples and selected for maximum asparaginase production. It was identified following the Bergey’s Manual of Determinative Bacteriology and phylogenetic analysis by 16S rDNA nucleotide sequencing. The organism was found to be Brevibacillus borstelensis ML12. The environmental parameters for asparaginase production include pH (5–10), temperature (25–40°C), inoculum volume (1–10%), fermentation medium volume (25–125 mL), fermentation time (16–48 h), age of culture (16–30 h), and shaking RPM (80–140 rpm). The statistical techniques, Plackett–Burman (PB) design, and response surface methodology (RSM) were further used for the optimization process, using Minitab 18 software. PB design composed of 12 trials and resulted in three significant parameters such as medium volume, inoculum volume, and shaking speed. RSM was employed to detect the optimum conditions for asparaginase production. The maximum production of asparaginase was achieved at media as 50 mL; inoculum as 6%; and shaking RPM as 120 rpm. There is no literature available on the production of asparaginase by B. borstelensis ML12; thus, after characterization, it may be used in pharmaceutical and food processing industries.