Research Projects

The 2G biorefineries that convert non-food lignocellulosic biomass to biofuel, biomaterials, and biochemicals play pivotal in waste management, sustainability, and biobased value chains. The government of India’s “PM JI-VAN Yojana” outlays Rs. 1969.50 crore till the period of 2029 to support 12 commercial and 10 demonstration scale projects to achieve targets of Ethanol Blending Petrol program. This requires biorefinery capacity building to produce 1750 crore Liters annually from the current 500 crore Liters. Not only Indian Maharatna-Navartna industries but also private sector companies are gearing up to achieve this target. Our country generates a surplus of agricultural and sustainable forestry lignocellulosic waste to meet the demand, but high capital and operational expenses of the lignocellulosic pretreatment unit are the bottleneck in developing economically feasible and commercially viable biorefinery technology. Current higher costs are due to the dominance of international suppliers of the pretreatment enzymes and the limited availability of the patentable indigenous enzyme technology. The enzymes utilized in biorefineries belong to two major classes: lignin hydrolyzing and carbohydrate (cellulose-hemicellulose) active. Once the lignin is recovered/separated from the cellulose-hemicellulose fraction of the biomass, the cellulose-hemicellulose fraction is hydrolyzed, and the biorefineries can diversify their product streams through efficient raw material utilization to meet the growing market demands, and generate revenue. Such integrated biorefineries are also aligned with the UN’s SDGs. We have characterized novel enzymes of both these classes from various environmental and industrial waste management settings. This work proposes to develop the existing enzyme repertoire, use synthetic biology to engineer microbial strains for their fermentative overproduction and develop their downstream processing for recovery and purification. The main goal of my work is to make the bioprocess robust and economical. The availability of this enzymatic technology will build integrated biorefineries that utilize the C6-C5 sugars as well as lignin. This work will involve two peripherals. First, on lignin hydrolyzing enzymes, wherein I will focus on laccases and peroxidases and their heterologous expression for overproduction. The second peripheral is building efficient carbohydrate-active enzyme fusions. Using synthetic biology tools, cellulases will be fused with carbohydrate-binding modules (CBM) for overexpression. Fermentations of these synthetic strains will be carried out at a lab scale and at a 5 L fermenter, and then they will be scaled up to a 50 L fermenter. Homogenization, filtration, and chromatography will be studied as downstream processing steps for enzyme purification and testing. This study will deliver patentable fermentative bioprocess for key enzymes involved in the pretreatment step of the lignocellulose-based biorefineries.