Role of systematic biology in biorefining of lignocellulosic residues for biofuels and chemicals production

Abstract

World has witnessed most unprecedented economic/industrial growth during past few decades. But this resulted in massive depletion in the fossil fuel reserves, and grave environmental concerns like green house gas emissions, climate change etc. Keeping in view the serious consideration there is a paradigm shift towards the exploration of renewable energy resources, and development of processes/products that are green, clean and ecobenign. Lignocellulosic biomass, being an inexpensive and abundant energy source could be exploited for the production of bioenergy and other oleochemicals. But due to recalcitrant nature of lignocellulosic biomass, which is attributed to presence of lignin and hemicelluloses making the substrate inaccessible to hydrolytic enzymes. Therefore, the major challenge in biomass to biofuel/bio-actives is conversion delignification of lignocellulosic biomass. With the application of appropriate pretreatment technique, the complex biomass can be partially loosened and made accessible for hydrolysis. Environment friendly and cost effective biological pretreatment method using microorganisms offers advantages in getting the desired results in energy efficient manner. Appropriate combination of hydrolytic enzymes is required for complete degradation of cellulose and hemicelluloses into simpler sugars which served as raw material for further transformation. Successful saccharification of lignocellulosic biomass results in release of fermentable sugars which could act as starting material for production of bioenergy (Bioethanol, biobutanol, biohydrogen, biogas etc.) and other value-added products (Bioplastic, animal feed, composites, enzymes, xylooligosaccharides etc.). With the advancement in technology (green biotechnology), the conversion costs of lignocellulosic biomass could be lowered and product yields could be enhanced making the production processes more economical and alleviating the deleterious effects of harsh chemicals and fossil fuels on environment.