Biosynthesis and chemical elucidation of antibiotics from Mangifera indica fruit juice and Zea mays grains using soil Bacillus isolate

The present study utilized soil Bacillus isolate as a cell factory for production of certain antibiotics from Mangifera indica fruit juice and Zea mays grain powder. Soil sample (10 g) was collected for Bacillus species isolation and re-culturing on sterilized Nutrient Agar (NA) at 37°C, followed by Gram staining and starch hydrolysis. Ripe Mangifera indica fruits were peeled, followed by the crushing of the pulp. The juice was filtered, and filtrate was kept as Mangifera indica fruit juice (MIFJ). Grains of Zea mays were mechanically grinded to obtain Zea mays grain powder (ZMGP). Fermentation of MIFJ and ZMGP was carried out inside 250 ml Erlenmeyer flask containing 100 ml of production medium for 192 h. Time-Course of antibiotics (peptide, macrolide and Fluoroquinolone) production was spectrophotometrically assessed by standard protocols at every 24 h for 192 h. Fermentation broths were centrifuged and subjected to High Performance Liquid Chromatography (HPLC). Whitish colonies on Nutrient Agar plate revealed growth of Bacillus species, which were rod-shaped and positive for both Gram staining and Starch hydrolysis. Maximum concentrations of peptide antibiotics in the fermentation broths of MIFJ and ZMGP were found to be 114.96 µg/ml (120 h) and 117.79 µg/ml (114 h). In the Bacillus fermentation of MIFJ and ZMGP, maximum concentrations of macrolide antibiotics were 333.38 µg/ml and 340.11 µg/ml at 192 h. Fluoroquinolone antibiotics concentrations in MIFJ and ZMGP broths were noticed at 192 h (340.11 µg/ml) and 96 h ((959.49 µg/ml). HPLC chromatogram shows Spectinomycin (35.15%) and Kanamycin (35.35%) as prominent antibiotics in MIFJ, while Bacitracin B (11.49%), Bacilysin (24.23%) and Bacillomycin D (12.34%) were prominent in ZMGP. This study shows that soil Bacillus species could be exploited in fermentation of Mangifera indica fruit juice and Zea mays grains powder to produce important antibiotics.