Kinetics of 2,3‐butanediol fermentation by Bacillus amyloliquefaciens: Effect of initial substrate concentration and aeration

Most studies on 2,3‐butanediol production by microbial fermentation have been carried out using Klebsiella oxytoca and Bacillus polymyxa. In these fermentations there is a significant conversion of carbon source into ethanol, glycerol and various organic acids as by‐products. On the other hand, this investigation has shown that the major products of fermentation by Bacillus amyloliquefaciens are 2,3‐butanediol and some minor acids. In a typical fermentation about 33 g of butanediol was produced from 100 g of glucose. The effect of pH, various carbohydrate source, initial glucose concentration and aeration on the 2,3‐butanediol fermentation by B. amyloliquefaciens were investigated. The butanediol productivity and yield was found to be highest with glucose as the carbohydrate source. The glucose concentration was varied between 30 and 100 g dm−3 with oxygen transfer rate controlled between 47.5 and 78.0 h−1. Oxygen and the initial substrate concentrations significantly influence the yield, productivity and by‐product formation.