Isolation, Identification and Optimization of growth medium with Acid Whey for the production of Beta-Galactosidase by Dairy Soil derived Streptomyces thermocarboxydus (strain NBRC 16323)
Description
β-galactosidase (EC3.2.1.23) is the enzyme that catalyzes the hydrolysis of β-1,4-D-galactosidic linkage in lactose releasing D-glucose and D-galactose as end products. The enzyme holds utmost significance in food and dairy industries to manufacture lactose-hydrolyzed products for lactose-intolerant people . Also β-galactosidases can synthesize galacto-oligosaccharides (GOS) that form the vital prebiotics to improve gut health by enhancing probiotic intestinal bacterial population. Dairy whey, main byproduct of cheese industry comprising of lactose, minerals, and proteins on commercial scale is usually disposed into water streams, thus creating severe water and environment pollution.(6).β -galactosidases can be used to treat whey to convert it into useful products such as ethanol and syrup sweeteners that have further applications in confectionary, bakery and pharma industries.Microbial production of the enzymes offers merits like ease of fermentation, higher productivity and consequently cost reduction using agro residues and affluents. Although Escherichia coli is the predominant source of β -galactosidase, crude isolates of enzyme from these coliforms may not be preferred in food processes owing to possible unsafe factors associated with them. Actinomycetes group of microbes has not been explored before for β-galactosidase production and utilization. Hence the present study is aimed to isolate β-galactosidase producing Actinomycetes , optimize the growth and process variables by OVAT ( one variable at a time) method for highest enzyme production and identification of that isolateby phylogenetic tree analysis. Newly isolated Streptomyces thermocarboxydus (strain NBRC 16323) showed highest enzyme activity at pH 8 and temperature 41°C for an incubation time of 72 h with 1% (v/v) of 3day old inoculum. Maximum enzyme production is attained at a concentration of 1% acid whey , 1% of casein and NaNO3 and 5mM of Mg2+ ions. Cell permeabilization treatments of the new isolate with SDS-Chloroform and Lysozyme gave highest enzyme yield. When compared with the basal growth medium a 2x fold increase in the enzyme production is achieved. Thus the above study offers the isolation of a new Actinomycetes strain that holds promising prospects for utilization of whey for lactose hydrolysis and galacto -oligosaccharides synthesis.
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Steps to reproduce
Primary Screening, Secondary screening, Beta -galactosidase -ONPG Assay, Phylogenetic Identification, One variable at atime approach , Cell permeabilization