Media Optimization For The Production Of Β-Galactosidase By a Novel Actinomycetal Isolate Via OVAT Methodology

In this study β -Galactosidase producing Actinomycetes were isolated from dairy soil and screened by enzyme assay. The isolate with highest enzyme activity was selected for further growth optimization studies . Process variables namely incubation time, incubation temperature , pH of the medium, Carbon and Nitrogen sources, metal ions, age and volume of inoculum , cell disruption methods were optimized by OVAT (One Variable At a Time) approach. The isolate showed highest enzyme activity at pH 8 after 72 hours of incubation at 41°C. Optimum age and volume of the inoculum was found to be 72 hr old and 1%(v/v) respectively. Beta-Galactosidase production was highest with Whey and Casein as Carbon and Nitrogen sources respectively. Mg++ at 5mM was found to be enhancing the enzyme production. β -Galactosidase yield was highest when cells were permeabilized with SDS-chloroform followed by Lysozyme. By employing 16s rDNA sequencing and phylogenetic analysis the isolate was identified as Streptomyces thermocarboxydus strain NBRC 16323.Study was validated by comparing β -galactosidase production of basal (unoptimized) medium to that of OVAT optimized media and it showed 2x fold increase.