A halotolerant fungal isolate Aspergillus tubingensis GR1 was isolated from the man-made solar saltern located at Khambhat, Gujarat, India, and identified using 28S rDNA partial genome sequencing. This isolate was studied for β-galactosidase production under solid state fermentation using wheat bran and deproteinized acid cheese whey. The influence of various agro-industrial wastes, nitrogen source and other growth conditions on β-galactosidase production was investigated using ‘one-factor-at-a-time’ approach. Among various variables screened along with wheat bran and deproteinized acid cheese whey as major growth substrate, corn steep liquor and MgSO4 were found to be most significant. The optimum concentrations of these significant parameters were determined employing the response surface central composite design, revealing corn steep liquor concentration (2 mL) and magnesium sulphate (50 mg) per 5 g of wheat bran and 20 mL of deproteinized acid cheese whey for highest enzyme production (15,936 U/gds). These results suggest the feasibility of industrial large-scale production of β-galactosidase known to be valuable in whey hydrolysis and removal of galactosyl residue from polysaccharide.

Introduction: Submerged fermentations (SmF) for enzymes production are typically applied with a substrate, that is either dissolved or remains suspended in an aqueous medium. For majority of the massive scale enzyme production SmF technology is most popular because of higher observance and simple handling (Pandey et al., 2010). Optimization of fermentation conditions, significantly physical and chemical parameters, is vital within the development of fermentation processes because of their impact on the economy and usefulness of the method. The growth and enzyme production of the organism are powerfully influenced by medium composition therefore improvement of media elements and cultural parameters is that the primary task during a process (Pandey et al., 2003). To satisfy the growing demands within the industry it's necessary to enhance the performance of the system and therefore increase the yield while not increasing the value of production. Enzyme prices are often reduced by finding optimum conditions for their production (Ponce-Noyola and de la Tom, 2001). β-galactosidase belongs to the cluster of saccharides converting enzymes within the family of hydrolases. It's unremarkably referred to as lactase. They're widespread distributed in various biological systems, e.g. microorganisms, plants and animal tissues. Compared to animal and plant sources