A NOVEL Scytalidium SPECIES: UNDERSTAND THE CELLULOLYTIC SYSTEM FOR BIOMASS SACCHARIFICATION

Abstract

In order to overcome the bottlenecks related to lignocellulosic-derived sugars, the search for more efficient enzymatic cocktails, containing a broad-spectrum of specific activities, relies on an important feature. This paper describes new enzyme activities derived from the novel strain of the Scytalidium genus isolated from the Amazonas rainforest. The production of the enzymatic cocktail was induced by delignifiedhydrothermal bagasse (DHB), and yeast extract was used to improve secretion activities, resulting in a positive influence on total cellulase activity. The enzymatic cocktail produced by this novel strain contains specific activities for biomass degradation, including FPAse, xylanase and β-glucosidase. Moreover, it is capable of hydrolyzing 62% of the alkaline pretreated bagasse, surpassing in 14% the hydrolytic capability achieved by the commercial cocktail Celluclast. To this extent, the strain described here emerges as a reliable alternative to other available enzymes and, consequently, amplification of available specific substrate activities.

Factors that influence the enzymatic hydrolysis of agricultural wastes for ethanol production: a review

“…A simple and rapid screening method is the evaluation of the fungal growth on petri plates containing microcrystalline cellulose (Avicel) as the sole carbon source and staining with Congo red, which reveals halos of hydrolysis. For example, Delabona et al (2019) screened 156 isolates of the genus Scytalidium and selected an enzyme cocktail obtained from the MIBA247 strain, using sugarcane bagasse as substrate for fungal growth. This enzymatic extract was able to hydrolyze 62% of bagasse, demonstrating the high potential of this strain for the production of enzymes by SSF and for saccharifications of lignocellulosic biomass.…”

“…The scientific literature considers that the hydrolysis of lignocelluloses with solids content greater than 20% requires at least 10 FPU of cellulase load per gram of biomass (Jung et al, 2017;Lucarini et al, 2017;Mukasekuru et al, 2020). Studies using homemade enzymes often apply the same enzyme dosage (10 FPU/g) used for commercial enzymes (Garcia et al, 2018;Delabona et al, 2019;Rodrigues et al, 2021). Nevertheless, in general, the sugar yields tend to be higher when commercial enzymes are used (Gomes et al, 2018;Mukasekuru et al, 2020).…”

“…Conversely, the search for lowcost homemade cocktails with high activities of cellulases and accessory enzymes is essential to optimize and economically viable the saccharification processes. For example, Delabona et al, (2019) compared the performance of an onsite extract produced by Scytalidium sp. MIBA247 with the commercial Celluclast® cocktail using both in the concentration of 10 FPU/g of sugarcane bagasse and observed a superior efficiency of the Scytalidium extract in the glucose yield.…”

“…2020). For that, studies looking for new microbial producer species of hydrolytic enzymes have been carried out, with filamentous fungi cultured in monocultures or in consortia (Rodrigues et al, 2017;Delabona et al, 2019;de Souza et al, 2021). For example, Rodrigues et al (2020) produced enzymatic cocktails by SSF, using sugarcane bagasse and wheat bran as substrates for the fungal growth, and the action of such cocktails was investigated in sugarcane bagasse saccharifications in order to replace commercial cocktails (Rodrigues et al, 2021).…”