Optimising Cellulase cocktail for bio-saccharification using stochastic model

Choudhary, Abhijeet (2022) Optimising Cellulase cocktail for bio-saccharification using stochastic model. Masters thesis, Indian Institute for Science Education and Research Kolkata.

Text (MS dissertation of Abhijeet Choudhary (17MS167)) 17MS167_Thesis_file.pdf - Submitted Version Restricted to Repository staff only Download (3MB)

Abstract

With the ever-increasing population, energy demands are drastically shooting up. This has resulted in shortages of most fossil fuel resources.Adding to this, the sudden climate changes due to excessive emission of greenhouse gases as a result of fossil fuel consumption have resulted in the development of a significant focus on the biofuel economy. Biofuels are liquid or gaseous fuels that are derived from organic materials such as plants or algae and waste materials like agricultural crops. They are considered to be carbon neutral as it does not contribute to additional carbon intake. Plants use energy from sunlight to convert CO₂ to chemicals making up its body. So utilizing them for energy demands results in recycling the sources. In addition to this, the burning of biofuels results in the generation of greenhouse gases which has a lower lifecycle in the atmosphere hence addressing the concerns of climate change. Despite the economic and environmental benefits, the utilization of food crops for biofuel production has created many controversies, as with the increasing population, food shortage is also a concern. Among the wide range of biofuels produced from variable sources, secondgeneration biofuels have attracted much attention primarily because they are produced from plant materials that are not utilized as food resources. They are produced primarily from lignocellulosic biomass, which includes forest residues like wood, agricultural waste like straw, and industrial waste materials like pulp from paper industries. However, their utilization in the production of second-generation biofuel is currently limited due to its recalcitrant structure contributed by lignin and hemicellulose, making them non-susceptible to enzymatic degradation. To improve the hydrolytic efficiency and reduce enzyme demand for making saccharification of lignocellulose economical, one effective strategy is to optimize the cellulase cocktail. i;e finding a ratio of endoglucanase, cellobiohydrolase, and β-glucosidase, which will yield maximum glucose conversion for a particular cellulose substrate.Production of enzymes and performing experiments on various substrates with high structural and chemical variability is a cumbersome and expensive process. In this study, we try to reproduce the stochastic model based upon the Monte-Carlo method simulation technique[1] that will help us to understand the chemical and physical basis for maximum yield by any particular ratio of cellulases. Our current model takes factors related to substrates such as crystallinity, degree of polymerization, and chemical composition and dynamical factors such as enzyme crowding and product inhibition by glucose and cellobiose into account. In the end,we looked into the hydrolysis profile of cellulose substrate and concentration profile of sugars using endoglucanase I (EG I), cellobiohydrolase I (CBH I) enzymes simulated into the model.

Actions (login required)

View Item