Fungal pretreatment and associated kinetics of rice straw hydrolysis to accelerate methane yield from anaerobic digestion

The influence of three different fungal strains-namely, Pleurotus ostreatus (PO), Phanerochaete chrysosposrium (PC), and Ganoderma lucidum (GL)-on pretreatment of rice straw, followed by biochemical methane potential assay was evaluated on the basis of structural (Field Emission Scanning Electron Microscopy, X-ray diffraction etc.) and quantitative (soluble chemical oxygen demand, volatile fatty acids, etc.) analysis. Maximum lignocellulosic degradation was obtained with PC pretreated rice straw (36% more than an untreated sample), followed by PO. Enhancement in the methane yield after 5 weeks of inoculation time was obtained after pretreatment, which was 269.99, 295.91, and 339.31 mL/g VSadded, for PO, GL, and PC, respectively, 1.64-2.22-fold higher than the untreated one. Kinetic modelling of cumulative methane yield showed that modified gompertz model showed the best fit among all analysed models. This study demonstrated the usefulness of fungal species in enhancing the methane yield.