Antimicrobial activity of steady-state cultures of Bacillus sp. CCMI 1051 against wood contaminant fungi

The effect of changing dilution rate (D) on Bacillus sp. CCMI 1051 at dilution rates between 0.1 and 0.55 h−1 in a glucose-limited medium was studied. Biomass values varied between 0.88 and 1.1 g L−1 at D values of 0.15–0.35 h−1. Maximal biomass productivity was found to be 0.39 g L−1 h−1, obtained at D = 0.35 h−1 and corresponding to a 54.4% conversion of the carbon into cell mass. The highest rate of glucose consumption was 4.45 mmol g−1 h−1 occurring at D = 0.4 h−1. The glucose concentration inside the chemostat was below the detection level starting to accumulate around 0.4 h−1. Growth inhibition of fifteen strains of fungi by the broth of the steady-state cell-free supernatants was assessed. Results showed that the relative inhibition differ among the target species but was not influenced by the dilution rate changing.