An eco-friendly process integration for second generation bioethanol production from laccase delignified Kans grass

The field of second generation production process has immense potential to utilize and convert lignocellulosic biomass to biofuels and biochemicals. Among these, enzyme pretreated biomass specifically treated by oxido-reductive group of enzymes is gaining attention towards bioethanol production. Until now research has been focused towards biofuels and biochemicals production based on the physical, chemical and physic-chemical methods. Biological processes on the other hand are eco-friendly and sustainable in nature and are gaining more attention towards biofuels/biochemicals generation. Moreover, biomass feasibility in terms of availability and sugar content is still one of the major challenges in bioenergy sector. The present article emphasizes process integration for bioethanol production by utilizing laccase pretreated lignocellulosic feedstock. In the present study we have attempted to combine the different processes together for bioethanol production and compared it with the single process. The fermentation process has been optimized through response surface methodology that resulted in 63.2 gL⁻¹ of ethanol for partial simultaneous saccahrification and fermentation (P-SSF) and 57.91 gL⁻¹ of ethanol for simultaneous saccharification and fermentation (SSF) within 25–28 h. The surface area, pore size, and pore volume of the fermented biomass is found to be decreased after SSF and P-SSF that indicates extensive action of enzymes. Microscopic study showed surface distortion of the biomass after fermentation that revealed the effective action of saccahrifying enzymes on biomass during hydrolysis and fermentation. The obtained X-ray diffraction pattern showed the utilization of amorphous and crystalline cellulose which initially increased to 8.03% and thereafter decreased to 23.49%. Thus, the findings obtained in the present study supports the feasibility of the enzymatically pretreated biomass for bioethanol production.