Sequential optimization of bioprocess nutritional parameters for maximum l-asparaginase production from Pseudomonas aeruginosa BGR1I1

Abstract

l-Asparaginase enzyme belongs to the amidase group which carries out the deamination of asparagine to ammonia and aspartic acid. It has important applications in the pharmaceutical and food processing industries. Extensive screening of l-asparaginase producing bacteria from the rhizospheric soil was carried out. An efficient l-asparaginase producer was selected and identified by morphological, cultural, biochemical methods together with 16S rRNA sequencing as a Pseudomonas aeruginosa BGR1I1. A sequential optimization of bioprocess nutritional parameters was carried out using Plackett-Burman design (PBD) and response surface methodology (RSM) for maximum production of l-asparaginase from Pseudomonas aeruginosa BGR1I1. Fourteen processing variables were screened out using PBD. Four variables (glucose, asparagine, pH and time) found to be significantly affecting l-asparaginase production were further optimized by the central composite design of RSM. Maximum l-asparaginase enzyme activity (307 IU/mL) was obtained under the optimum concentration of glucose, 0.22% asparagine, 0.71% pH, 7.45 of modified M9 medium and incubation time 63 h which is 2.22-fold higher than in the basal medium.