Rekha Sethi, T. Padmavathi and S. B. Sullia
Lignocellulosic containing plants are those types of biomass that include wood, agricultural residues and paper wastes. They are composite polymeric material containing primarily cellulose, hemicellulose and lignin. Lignin is a complex three dimensional polymer composed of six carbon phenolic rings, with various carbon chains and other chemical functionalities. Lignin is non crystalline in nature and serves to bind the cellulosic fibers, making the lignocellulosic mass resistant to enzymatic degradation. Lignin is hydrolyzed by ligninases, thus releasing cellulose which can be used to produce ethanol. In the present work microorganisms were isolated from coastal areas of Tamilnadu and Karnataka and subjected to screening for lignocellulase activity. The organisms exhibiting maximal degradation were identified using 16s r RNA technique as Bacillus pumilus and Mesorhizzobium sps., two fungal species were identified as Aspergillus niger and Trichoderma viride. These organisms were used to breakdown 18 different lignocellulosic biomasses for a period of sixty days. The organisms exhibited different levels of degradation at different time intervals in various substrates. Maximum degradation was observed in about ten substrates commonly degraded by all the four organisms in the first three weeks. It was observed that Eucalyptus, Maize leaves, Crotalaria, Honge, Mango leaves and Jamun leaves showed a great potential as substrates which were maximally degraded and could be utilized for further work to obtain alternate fuel. Mesorhizobium sps., showed better degradation in all the substrates compared to the other organisms.
