Enhancement of biogas production from lignocellulosic feedstocks using bioaugmentation of high effective Bacillus spp

At present, the demand for energy tends to increase in line with the growth of the world economy. Consequently, the world is facing problems from global warming which is mainly caused by the use of fossil fuels. Therefore, the use of renewable energy is a way to help reduce such impacts that is continually receiving more attention. Biogas technology has been widely applied and successful in treating wastewater and various organic wastes.  The obtained biogas can be used as renewable energy as heating, electricity and transportation fuel. However, the biogas systems that use lignocellulosic feedstocks such as cassava pulp, wastewater from cassava-ethanol factory and Napier grass still has low efficiency. The hydrolysis step of these feedstocks is a major constraint that results in low methane yield. Therefore, the biogas systems need to operate with a long retention time. The preliminary study of our research team found that the bioaugmentation of Bacillus pumilus (TBRC 2887), which grows well at mesophilic temperature and neutral pH and has high cellulase and xylanase activities, could increase the methane production from cassava pulp up to 80% and gave a significantly higher methane production rate than other Bacillus strains. Therefore, to develop bio-augmentation process with Bacillus pumilus (TBRC 2887) for accelerating the rate of lignocellulose digestion and increasing the methane yield of lignocellulosic feedstocks more than 30%, this research will optimize the amount of Bacillus pumilus (TBRC 2887) and inducible additive and investigate the relations among microbiome characteristics, enzyme activity and operating conditions. The gain knowledge will be used to adjust process conditions that can be applied at the industrial level.