Studies on L Glutaminase Production and Its Potential Applications In Food Industry

Abstract

L-glutaminase (EC 3.5.1.2) is an amidohydrolase enzyme that catalyses the conversion of L-glutamine to L-glutamic acid and ammonia. L-glutaminase has attracted the food industrial sector as a flavor enhancing agent in oriental fermented foods like soy sauce, miso and sufu. The pleasant and palatable tastes of these fermented foods are considered to be related to the content of glutamic acid in them which is the product of the L-glutaminase. In the food industry, L-glutaminase is also used for acrylamide degradation and theanine production. The other applications include its use as a biosensor in hybridoma technology, as an antiretroviral agent and an anticancer agent to treat Acute Lymphocytic Leukaemia (ALL). newlineThe aim of present investigation was to isolate halotolerant L-glutaminase producers, their identification, production of L-glutaminase by solid state and submerged fermentation, purification, characterization and testing for its applications. newlineEnrichment and isolation of microorganisms newlineGlutaminase producing halotolerant bacteria were isolated from the water and sediment samples of the marine environment (Alibag), Lonar Lake (Buldhana) and from water sample of Salt pan (Nahur). newlineScreening of isolates for L glutaminase production by rapid plate assay method newlineAll the isolates showed positive results in the rapid plate assay method. The formation of pink colour around the bacterial colony indicates the pH alteration which originated from ammonia accumulation in the medium. newlineActivity of extracellular enzyme newlineThe formation of pink colour around the well confirms that extracellular L-glutaminase was produced by all the isolates. Isolates MM-2 and MM-5 showed high L-glutaminase activity as compared to other isolates. newlineIdentification of Isolates newlineThe isolates were identified by morphological, physiological, biochemical characterization methods and also by 16s rRNA sequencing and phylogenetic analysis. The isolates were identified as Bacillus subtilis MM1 (Accession No: MH447353.1), Pseudomonas aeruginosa MM2 (Accession no