Growth of bacillus coagulans using molasses as a nutrient source

Abstract

Bacillus coagulans (B. coagulans) can be utilized as microbial inoculant to speed up the bioremediation of wastewater. The effectiveness of the microbial inoculant for treatment is highly selective and relying on the characteristics of the wastewater. A feasible carbon source must be first chosen to pre-culture the microbe prior to the bioremediation. Commercial nutrient broths are efficient to grow the microbial; they are costly for the treatment of large volume of wastewater treatment. This study aims to evaluate the growth rate of B. coagulans using a cheaper nutrient source, i.e. molasses. The commercial Man, Rogosa and Sharpe (MRS) media was used as a benchmark. The growth rate of B. coagulans was conducted at different concentrations of molasses (1 %, 3 % and 5 % (w/v)) and in the MRS broth as benchmark. B. coagulans grown in the MRS has shown a much higher maximum specific growth rate (0.69 h-1) compared to that grown in 1 % (w/v) molasses (0.14 h-1). No growth was observed in the higher concentrations of molasses (3 and 5 % (w/v)). Measuring the colonyforming units of B. coagulans in both the MRS and molasses mediums validated the results. Molasses is a desirable carbon source as it is relatively cheaper and easily available. More studies are needed to improve the maximum specific growth rate of B. coagulans in 1 % (w/v) of molasses.