Optimization of enzymatic hydrolysis of cellulose extracted from bamboo culm for bioethanol production by Saccharomyces cerevisiae modified via CRISPR/Cas9

Author(s)

da Silva, Marcos F. ; Flaibam, Barbara ; de Melo, Allan H. F. ; Sampaio, Ulliana ; Clerici, Maria Teresa P. S. ; Goldbeck, Rosana

• Document type: Journal article
• Source: Food Research International; v. 192, p. 9-pg., 2024-07-19.

Abstract

In the context of biorefinery, researchers have been looking for lignocellulosic biomasses and ideal treatments to produce economically viable biofuels. In this scenario, the bamboo culm appears as a plant matrix of great potential, given the high cellulose content of low crystallinity. Thus, the objective and differential of this work was to determine the best conditions for enzymatic hydrolysis of cellulose extracted from bamboo culm and to evaluate its potential application in the production of bioethanol through Separate Hydrolysis and Fermentation (SHF) and Saccharification and Simultaneous Fermentation (SSF) by Saccharomyces cerevisiae modified via CRISPR/Cas9. The average cellulose extraction yield was 41.87 % with an extraction efficiency of 86.76 %. In general, as the hydrolysis time increased, an increase in glucose production was observed in almost all assays, with higher hydrolysis efficiency values at 72 h. The results ranged from 2.09 to 19.8 g/L of glucose obtained with efficiency values of 10.47 to 99 %. The best conditions were found in test 5 (temperature of 36 degrees C and pH 5.0, with only 10 FPU/g of substrate Cellic Ctec2 Novozymes (R) cocktail). It is observed that for all hydrolysis times the independent variables pH and temperature were significant under the hydrolysis efficiency, showing a negative effect, indicating that higher values of the same promote lower values of the response variable. For bioethanol production, a maximum concentration of 7.84 g/L was observed for the SSH process after 4 h of fermentation, while for the SSF process it was 12.6 g/L after 24 h of fermentation, indicating the large potential of the simultaneous process together with the application of bamboo culm biomass for high production of biofuel. (AU)

• FAPESP's process: 22/15221-1 - Xylooligosaccharides production from agroindustrial wastes and technological application in meat and plant-based products
• Grantee: Rosana Goldbeck Coelho
• Support Opportunities: Regular Research Grants
• FAPESP's process: 21/09527-8 - Integrated bioprocess for obtaining cello-oligosaccharides and cellulose nanocrystals through ultrasound-assisted enzymatic hydrolysis from agroindustrial wastes
• Grantee: Marcos Fellipe da Silva
• Support Opportunities: Scholarships in Brazil - Doctorate