Evaluation of ethanol production by metabolically engineered Bacillus subtilis BF1

The ever increasing global population requires more energy supplies for improving the quality of life. Multiple factors including fluctuations in fossil fuels prices, security issues and climate change have driven and forced the energy development towards alternative and renewable energy sources. Bioethanol is considered as a renewable biofuel that traditionally has been produced by ethanologenic organisms such as Saccharomyces cerevisiae and Zymomonas mobilis. Most of the ethanologenic strains can grow on a narrow range of substrates. In contrast, the non-ethanologenc Bacillus subtilis can grow on a wide range of substrates including industrial organic waste materials. In the current study the ethanologenic Bacillus subtilis BF1 was engineering using a synthetic operon of genes coding for pyruvate decarboxylase and alcohol dehydrogenase. The stain in the first step was evaluated for ethanol production using various concentraions of glucose. The results showed that the engineering approach was successful and Bacillus subtilis BF1 was able to produce about 27 g/l ethanol. The ethanol content in each sample was measured by a colorimetric method. The results are encouraging for further attempts to evaluate and improve ethanol production by this strain on other substrates such as industrial and agricultural wastes.

Keywords:

Renewable energy , Bioethanol production , Bacillus subtilis