(619bb) The Role of ‘Free Radical Based Mechanisms’ in Wood-Feeding Termites for the Deconstruction of Lignocellulosic Biomass

Wood-feeding termites are very efficient in deconstructing the plant cell wall, leading to more than ~90% of cellulose and hemicellulose solubilization in a span of 24 hours. The key to this efficient natural process is the mechanism of selective lignin modification in the termite gut as shown by previous studies, which characterized lignin subunits in termite chewed wood particles and feces. These studies have led to an important scientific question- what is the mechanism that helps termite to cleave selective lignin bonds, enough to avoid lignin recalcitrance for saccharifying enzymes?

In the present research, we are answering this question by designing a speculated free-radical driven system that can participate in lignin bond cleavages in such a manner that it would avoid lignin recalcitrance and subsequently allow bigger molecules like-enzymes to enter the matrix and catalyze the saccharifying reactions. The free radicals are small, highly reactive and unstable molecules like hydroxyl, superoxide etc., which play an important role in termite based pretreatment. These radicals can be generated and utilized in many enzymatic and chemical reactions. Therefore, this proposed free-radical system could be targeted as a mimic for designing a novel pretreatment process.