Sugarcane bagasse: an important lignocellulosic substrate for production of enzymes and biofuels

Sugarcane bagasse (SCB), a by-product of sugarcane industry, is a rich source of cellulose (45%), hemicellulose (32%), and lignin (17%) with low ash content. Being produced in large quantities by sugar industries, it is a great challenge for environment because it is mostly burnt in-open or either disposed improperly causing environmental pollution. Due to rich source of fermentable sugars, it is used as a substrate for producing microbial enzymes and biofuels. Secondly, high fuel prices, limited fossil fuel reserves, and environment pollution due to burning of fossil fuels have also highlighted the need for renewable and sustainable sources of energy such as biofuels. Sugarcane bagasse is a renewable, easily available, and cost-effective alternative for synthesis of biofuels and various microbial enzymes in submerged (SmF) as well as solid-state fermentations (SSF). However, for biofuel production, the main hindrance in utilizing bagasse is the requirement of large amount of enzymes for conversion of lignocellulosic biomass into fermentable sugars. Therefore, there is an utmost need for the production of enzymes using cost-effective and easily accessible substrates such as sugarcane bagasse followed by utilizing these enzymes for saccharification of carbohydrate polymers into fermentable sugars for biofuels. However, the presence of lignin hampers the saccharification of cellulose and hemicellulose into easily fermentable sugars. Therefore, pretreatment reduces lignin content of sugarcane bagasse and makes cellulose and hemicellulose easily accessible for enzymatic hydrolysis. Enzymatic hydrolysate can be further fermented to biofuels using aerobic and anaerobic microorganisms.

Automated summary

Sugarcane bagasse is a by-product of the sugarcane industry, rich in cellulose and hemicellulose with low ash content. It is a challenge for the environment as it is often burned or disposed improperly. However, it can be used as a substrate for producing biofuels and microbial enzymes. Pretreatment reduces the lignin content of sugarcane bagasse, making cellulose and hemicellulose more accessible for enzymatic hydrolysis.