Production of L-glutaminase and its optimization from a novel marine isolate Vibrio azureus JK-79

Abstract

L-Glutaminase is an amidohydrolase which is produced by a variety of micro-organisms including bacteria, yeast and fungi. It is currently used in the treatment of acute lymphoblastic leukemia (ALL) and human immunodeficiency virus (HIV). Another potential application of L-glutaminase is as flavor enhancing agent in soy sauce fermentation. Even though L-glutaminase activity was reported in numerous micro-organisms, production of L-glutaminase from marine bacteria is very scanty. With this view, in the present research work, L-glutaminase production pattern was studied under submerged fermentation using novel marine isolate Vibrio azureus strain JK-79 (GenBank Acession Number JQ820323) based on one-factor-at-a-time approach. The maximum yield of enzyme production (247 U/ml) was achieved in a seawater based medium at pH 8, 37°C, 1% inoculum concentration and 2% glutamine concentration for 24 h. The medium when supplemented with carbon source, it improved the enzyme production from 247 to 321 U/ml with 1.5% maltose. Addition of 2% soybean meal also improved the L-glutaminase production (289 U/ml). The above results indicate the scope for production of salt tolerant L-glutaminase using this novel marine bacterial strain.

Keywords: L-Glutaminase, Vibrio azureus JK-79, submerged fermentation, optimization of fermentation, one-factor-at-a-time approach.

Afr. J. Biotechnol Vol. 12 No. 50