Statistical Medium Optimization for the Production of Anti-Methicillin-Resistant Staphylococcus aureus Metabolites from a Coal-Mining-Soil-Derived Streptomyces rochei CMB47

The development of novel antibacterial drugs needs urgent action due to the global emergence antibiotic resistance. In this challenge, actinobacterial strains from arid ecosystems are proving be promising sources new bioactive metabolites. identified Streptomyces rochei strain CMB47, isolated coal mine Saharan soil, provided an ethyl acetate extract which tested against a series pathogens. It displayed minimum inhibitory concentration <0.439 µg/mL MRSA. A statistical experimental design using response surface methodology (RSM) based on second-order rotatable central composite (RCCD) was planned develop efficient fermentation process able improve metabolite production. optimal conditions were determined for starch and NaNO3 concentrations, incubation time initial pH value, reaching inhibition zone diameter 20 mm, close after validation model. bioassay-guided fractionation crude most active fractions, analyzed by HPLC equipped with photodiode array detector coupled online electrospray mass spectrometer (HPLC-DAD/ESI-MS), obtaining preliminary indications molecular structures These results support potential interest in further investigations into purification full characterization metabolites responsible biological activity observed so far.