Optimization studies of L-glutaminase production from Halomonas hydrothermalis B-15-9-2 isolated along Gujarat coasts

Abstract

L-glutaminase (EC 3.5.1.2) is an enzyme grouped under amidohydrolase and a member of serine-dependent β-lactamases & penicillin-binding proteins. The present study focuses on increasing the yield of L-glutaminase from marine bacteria isolated from coastal regions of Gujarat. Using enrichment culture technique marine samples were enriched and physicochemical analysis was done. A total of 12 bacteria isolated from Gujarat coasts were screened for L-glutaminase biosynthesis. Out of 12, most potent one isolate B-15-9-2 was selected for cultural, biochemical, and molecular identification by 16S rRNA analysis, which reveals the nearest homolog is Halomonas hydrothermalis with 99.87% similarity. To the best of our knowledge this is the first report of Halomonas hydrothermalis as L-glutaminase producer from Gujarat coasts. Further study deals with the optimization of medium components for higher yield of L-glutaminase by one variable at a time & response surface methodology. There was a significant increase in the L-glutaminase activity about 3.4-fold from 29 ± 0.8 U/mL to 98.95 ± 0.5 U/mL upon media optimization via statistical method.