Aplicação do extrato enzimático produzido por penicillium sp. fsde 15 na conversão da biomassa do pé de milho em açúcares fermentescíveis

Abstract

With the continuous depletion of fossil fuel reserves and the increase in emissions of harmful gases into the atmosphere, the need to explore renewable, sustainable, and accessible energy sources is growing. In this regard, second-generation ethanol has gained prominence as a viable alternative to traditional fuels, as it is produced from lignocellulosic materials, such as agricultural waste. Corn stover is a waste generated in large quantities after corn harvesting, and its composition allows for its use in the production of second-generation bioethanol. The objective of this study was to physicochemically characterize corn biomass and establish suitable values for the parameters of enzymatic hydrolysis of the biomass using the cellulolytic complex produced by Penicillium sp. FSDE 15. Additionally, acidic pre-treatment of the residue was conducted, and enzymatic hydrolysis was performed before and after the pretreatment, with the quantification of reducing sugars (RS) produced. The liquors obtained during the pre-treatment and enzymatic hydrolysis were fermented, and the °Brix and RS values were quantified before and after the process, monitoring the consumption of fermentable sugars. During the hydrolysis trials, the peak production of reducing sugars in the first few minutes of reaction demonstrated the efficiency of converting cellulose into glucose, with a productivity of 24.2%, highlighting the applicability of the enzymatic complex obtained from Penicillium sp. FSDE 15 for obtaining fermentable sugars from raw biomass. Enzymatic hydrolysis after acidic pre-treatment showed RS production four times lower than that from the raw biomass, indicating the production of inhibitors during the pre-treatment. The liquors, after filtering the acidic pre-treatment and enzymatic hydrolysis, were fermented, with maximum ethanol yields of 1.828 g/L after the first wash of the pre-treated residue and 1.354 g/L after the enzymatic hydrolysis of the raw material. It was found that the use of filamentous fungi, which are generally not commercially used for the production of cellulases, represents a new alternative for the complete utilization of cornfields after harvesting. Furthermore, corn stover shows great potential for the production of second-generation ethanol.