Efficacy of Lignocellulolytic Fungi on the Biodegradation of Paddy Straw

Paddy straw is one of the most abundant agricultural by-products in Tamil Nadu, India. It contains high amounts of cellulose and lignin. The fungal strains were isolated from naturally decomposing sites of paddy straw. Eight fungal strains were isolated and later these eight fungi were used for finding out their potential for the degradation of lignin and cellulose content of paddy straw. Among eight fungi tested, three fungal strains showed lignocellulolytic activities. Hence, these three fungal strains were used for the decomposition of paddy straw both individually as well as in various combinations. Inoculation of these lignocellulolytic fungi in paddy straw accelerated the process of paddy straw decomposition when compared to control. Significant reduction in lignin and cellulose content were observed in paddy straw inoculated with mixed culture of R. oryzae + A. oryzae + A. fumigatus compared to other experiments. Mixed culture of three fungal strains reduced C:N ratio to 10:1 compared to 70:1 in paddy straw mixed with soil. A significant increase was also observed in macro nutrients of the compost harvested from E8 experimental trays. It is evident from the results that the mixed culture of all the three lignocellulolytic fungi may be used for the degradation of paddy straw. Hence we conclude that combination of three lignocellulolytic fungi viz.,R. oryzae, A. oryzae and A. fumigatus can be recommended for the degradation of paddy straw which would result in production of good quality compost containing higher amounts of total nitrogen (1.55±0.03%), total potassium (1.57±0.01%) and total phosphorus (1.48±0.17%) content.