Microbial pretreatment of water hyacinth for enhanced hydrolysis followed by biogas production

Abstract

Abstract Biological pretreatment with novel isolated microbial pure culture was utilised to pretreat water hyacinth to enhance its solubilisation followed by biogas production. Lignocellulose degrading bacterial strains isolated from soil (Bordetella muralis VKVVG5) (UN3d2), the gut of silverfish (Citrobacter werkmanii VKVVG4) (SFa2) and millipede (Paenibacillus sp. VKVVG1) (BrB2) were employed to optimise the ideal bacterial strain illustrating accelerated hydrolysis of water hyacinth. Citrobacter werkmanii VKVVG4 pretreatment of water hyacinth with an optimum dosage of 109 CFU/mL and time of 4 days helped in achieving the highest solubilisation of 33.3%. Biochemical methane potential (BMP) test was conducted between untreated and Citrobacter werkmanii VKVVG4 pretreated water hyacinth. Biochemical methane potential (BMP) test of pretreated water hyacinth illustrated faster start up period than the untreated water hyacinth. Citrobacter werkmanii VKVVG4 (SFa2) pretreated water hyacinth illustrated a cumulative biogas production of 3737 ± 21 mL whereas untreated water hyacinth illustrated a cumulative biogas production of 3038 ± 13 mL on the 50th day. Scaled up batch (20 L) study demonstrated a three times increase in the cumulative biogas generation of the microbial pretreated water hyacinth than the untreated water hyacinth.