The preliminary optimization of culture components for improving antifungal production by a wild-type soil bacteria Bacillus subtilis

Antifungal compounds are produced by Bacillus species under various growth conditions. While optimizing the antifungal production by using the one-factor-at-a-time (OFAT) and response surface methodology (RSM) approaches mannose and malt extract were identified as the most suitable carbon and nitrogen sources respectively. The RSM was applied to determine the optimum conditions of the three parameters such as pH, carbon and nitrogen sources for improved production. Optimum concentrations of carbon and nitrogen sources were 0.3% and 0.6% respectively with optimum media pH of 7.0 which showed optimum value of 40 AU/ml of antifungal compound against the Candida albicans SC5314 used as an indicator strain. In the present study, the F-value was determined as 0.0034 to imply that the model is significant. The goodness of the fit of the model was tested using coefficient of determination, R2  value, that tantamounts to 0.8562. The identification of antifungal compounds with their molecular masses was accomplished by MALDI-TOF mass spectrometry after n- butanol extraction. The present study thus has provided a platform to upgrade the yield of antifungal compounds which have got immense clinical potential to tread Candidosis.