OPTIMIZATION OF RIBOFLAVIN PRODUCTION USING BACILLUS CEREUS HDS07: A STRAIN ISOLATED FROM AGARICUS BISPORUS

Abstract

The current study focused on the production and optimization of riboflavin from Bacillus cereus, a strain isolated from Agaricus bisporus. Seven different strains were isolated from Agaricus bisporus and screened for riboflavin production. Among the 7 strains, only 4 strains were identified as riboflavin producers by riboflavin assay medium (RAM). To determine the potency of the strains, selected strains were exposed to roseoflavin – an analogue of riboflavin. The potent strain was identified through morphological, biochemical, and molecular characterization and the strain name was designated as HDS07. Estimation of riboflavin was done by UV Spectrophotometry. Riboflavin production was done in Chemically Defined Medium (CDM) and De Man, Rogosa and Sharpe agar (MRS) using a strain Bacillus cereus HDS07. To enhance riboflavin production, the medium was optimized with different parameters like carbon, nitrogen sources, pH, temperature, and inoculum size. The potent strain HDS07 was identified as Bacillus cereus by 16S rDNA sequencing and NCBI-Gen Bank accession number - MK177597 was obtained. Riboflavin production from Bacillus cereus-HDS07 was more in the MRS medium than that of CDM. It was found to be 2.97 mg/L and 1.8 mg/L correspondingly. The maximum riboflavin (3.48 mg/L) was obtained from Bacillus cereus-HDS07 under the culture conditions; glucose, glycine, pH-6, 30℃, and 3% inoculum size. The current study emphasizes that the isolated potent strain Bacillus cereus-HDS07 from Agaricus bisporus could be used as a starter for the industrial production of riboflavin.