Enhancement of Halophilic Glutaminase Producing by Tetragenococcus muriaticus FF5302 in Bioreactor

Abstract

From Thai fermented fish sauce (Nam-pla), 59 bacterial isolates of halophilic glutaminase-producing bacteria were isolated. The hydrolysis of glutamine served as the primary screening procedure. It was discovered that strain FF5302 was an influential producer of the extracellular halophilic glutaminase enzyme. The moderately halophilic bacterium Tetragenoccus muriaticus FF5302 was identified through sequence analysis of the 16S rRNA gene, phylogenetic tree analysis, and phenotypic identification before it was possible to determine the optimal nutritional and culture conditions for its halophilic glutaminase activity. The purpose of this research was to determine the optimal nutritional and cultural conditions for producing halophilic glutaminase activity in a stirred tank bioreactor with a volume capacity of 3 L. The production of halophilic glutaminase from strain FF5302 was investigated by optimizing various physicochemical parameters. Seven potential factors are generally considered in halophilic glutaminase production, namely NaCl concentration, initial pH, temperature, incubation time, nitrogen sources, carbon sources, and inoculum size. According to the findings, the amount of halophilic glutaminase in the inoculum had an effect on the growth and activity of the enzyme when it was present at a concentration of 5 % (v/v). It was also found that halophilic glutaminase showed the highest activity (87.4 U mL−1) of strain FF5302 in SGC liquid medium containing NaCl 20 % (w/v), pH 8.0, agitation at 200 rpm, and an aeration rate of 0.05 VVM at 37 °C for 120 h. The size of the inoculum influenced both the proliferation and activity of halophilic glutaminase in the inoculum. Consequently, T. muriaticus FF5302 possessed an exceptional capacity to synthesize halophilic glutaminase. Furthermore, the halophilic glutaminase enzyme from halophilic bacteria is a prospective option for usage in the food industry as an aroma and flavor enhancer. HIGHLIGHTS muriaticus FF5302 was exceptionally capable of producing halophilic glutaminase. In addition, the enzyme is a viable candidate for usage in the food industry as an aroma and flavor enhancer. Furthermore, this study could also be helpful and valuable in improving enzyme productivity at the bioreactor scale for various industrial applications. GRAPHICAL ABSTRACT