Out of 13 amino acids, only arginine, glutamate, asparagine, aspartate, tryptophan and histidine favored the growth and metabolite production (Table

3). Among them, arginine, glutamate and tryptophan promoted the maximum Modulators biomass accumulation (2.6 mg/ml) than the other amino acids. The remaining amino acids yielded relatively less amount of antibiotic. The maximum biomass (3.6 mg/ml) and metabolite production was favored at 2.0 g/l concentration of K2HPO4 (Fig. 1). Similarly the effect of different concentrations of MgSO4.7H2O on growth and metabolite yield was also studied. The results indicate that the concentration of both the metal ions strongly influence the antibiotic production. The concentration Tyrosine Kinase Inhibitor Library solubility dmso of 1.0 g/l MgSO4.7H2O promoted the maximum

growth (3.2 mg/ml) and antimicrobial compound production (Fig. 1). In addition to culture media, cultural conditions strongly influence the antimicrobial compound production. The effect of cultural conditions on growth and production by the isolate BTSS-301 has been studied in detail. Maximum antibiotic yield was obtained at 30 °C with biomass of 3.6 mg/ml (Fig. 1). The increase of incubation temperature from 20 °C to 30 °C increased the growth of biomass and the production of metabolite respectively. However, the yield decreased consistently with the cell mass by increasing http://www.selleckchem.com/products/PF-2341066.html the growth temperature range from 35 to 50 °C. Even though biomass was deposited at 45–50 °C, the antibiotic yield was

negligible. The maximum antibiotic yield was obtained at pH 7.2 with a biomass of 2.8 mg/ml (Fig. 1). The growth and antibiotic production by the isolate BTSS-301 was monitored over a period of 120 h. The antibiotic production occurred in a growth phase dependent manner and the highest yield was obtained in the late exponential phase and the stationery phase. The maximum yield was obtained second at 96 h incubation period with biomass of 3.9 mg/ml (Fig. 1). The agitation provides greater aeration to the culture and also creates conditions for greater availability of nutrients to cells. The highest metabolite yield was obtained at 180 rpm with biomass of 3.2 mg/ml (Fig. 1). Further increase in the agitation speed demonstrated rapid decrease in yield along with biomass. The fermentation process was carried out for 96 h at 30 °C. After incubation period, the culture supernatant was separated by centrifugation at 3000 rpm for 15 min. the culture filtrate was extracted twice with ethyl acetate (1:2, v/v) and the organic layer was evaporated to dryness under reduced pressure to give yellow colored precipitate. 5 g of the precipitate in 50 ml of methanol was chromatographed on silica gel column using solvent system chloroform and methanol (7:3, v/v). A total of 30 fractions of 5 ml each were collected. Among all the fractions tested for antimicrobial activity, active fractions were ranged between fraction no.11–23.