L-Glutaminase production by Marine Bacteria

L-glutaminases (L—glutamine amidohydrolase EC.3.5.l.2) is proposed as a prospective candidate for enzyme therapy cnf cancer and also as zui important additive during enzymatic digestion of shoyu koji since it could enhance glutamate content of soysauce. Commercial production of glutaminase could make possible its wide application in these areas, which would demand availability of potential sources and suitable fermentation techniques. The ‘present investigation highlighted marine environment as a potential source of efficient glutaminase producing bacteria mainly species of pseudomonas, aeromonas ,vibrio,alcaligenes, acinetobacter bacillus and planococci.Among them pseudomonas fluorescens ACMR 267 and v.cholerae ACMR 347 were chosen as the ideal strains for glutaminase production.Extracellular glutaminase fraction from all strains were in higher titres than intracellular enzymes during growth in mineral media, nutrient broth and nutrient broth added with glutamine.Glutaminase from all strains were purified employing (NH4)2SO4 fractionation followed tnr dialysis and ion exchange chromatography. The purified glutaminase from all strains were observed to be active and stable over a wide range of gfii and temperature.Optimization studies cflf environmental variables that normally influence time yiehi of glutaminase indicated that the optimal requirements of these bacteria for maximal glutaminase production remained stable irrespective of the medium, they are provided with for enzyme production. However, solid state fermentation technique was observed to be the most suitable process for the production of Glutaminase.

Studies on L-glutamic acid Production using Brevibacterium sp.

The thesis comprises a set of experiments mainly focused on the improvement of L-glutamic acid fennentation. Much attention has been given to use of locally available raw materials, culturing the organism on inert solid substrates and also immobilization of the bacterial cells from the view point of long term utilization of biocatalyst and continuous operation of the stabilized system. Studies were also carried out for the down stream processing for the extraction and purification of L-glutamic acid. An attempt was made to study the morphological features of the microorganism including the cell premeability. In relation with the accumulation of glutamic acid within the cells an approach was made to study the behaviour of the Brevibacterium cells when they are exposed to hyper osmotic environment. Attempts were also made to study the requirement of iron and production of siderophores by this microbial strain. The search for a suitable nitrogen source for glutamate fermentation ended with a promising result that they got a potent urease activity and it can be utilized for many biotransfonnation studies. The entire thesis is presented in three sections, viz. introductory section, experimental section and the concluding section