Starch degrading bacteria for biohydrogen production

Abstract

Global research is moving forward in developing biological production of hydrogen as a renewable energy source in order to reduce the use of non-renewable energy. Biohydrogen has the potential of replacing the hydrogen production by fossil fuels which is one of the major factors that cause the global warming. The amylolytic activity of several microorganisms capable of utilizing starch in the dark fermentation process has provided a great potential in biohydrogen production by the starch degrading bacteria. In this study, starch utilizing bacteria have been successfully isolated from cassava chips processing wastewater and sludge. Based on the morphological characteristics, the isolate was found to be Gram positive bacteria with spherical cell shape. 16S rRNA analysis identified the strain Lactococcus sp. SDB4 with 92% similarity to Lactococcus lactis. The partial 16S rRNA sequence has been deposited to GenBank with Accession Number KU160544. Furthermore, the isolate was subjected to anaerobic dark fermentation process using synthetic media with tapioca starch as the only source of carbon. The findings in this study indicate that the Lactococcus sp. SDB4 possesses an amylolytic activity and capable of utilizing starch efficiently (75%). This strain has the potential to be used in biohydrogen production using starch containing wastewater as substrate.