Characterization of sugarcane bagasse solubilization and utilization by thermophilic cellulolytic and saccharolytic bacteria at increasing solid loadings

Author(s)

Zambello, Isabela U. ; Holwerda, Evert K. ; Lynd, Lee R.

• Document type: Journal article
• Source: Bioresource Technology; v. 406, p. 11-pg., 2024-06-20.

Abstract

In Brazil the main feedstock used for ethanol production is sugarcane juice, resulting in large amounts of bagasse. Bagasse has high potential for cellulosic ethanol production, and consolidated bioprocessing (CBP) has potential for lowering costs. However, economic feasibility requires bioprocessing at high solids loadings, entailing engineering and biological challenges. This study aims to document and characterize carbohydrate solubilization and utilization by defined cocultures of Clostridium thermocellum and Thermoanaerobacterium thermosaccharolyticum at increasing loadings of sugarcane bagasse. Results show that fractional carbohydrate solubilization decreases as solids loading increases from 10 g/L to 80 g/L. Cocultures enhance solubilization and carbohydrate utilization compared to monocultures, irrespective of initial solids loading. Rinsing bagasse before fermentation slightly decreases solubilization. Experiments studying inhibitory effects using spent media and dilution of broth show that negative effects are temporary or reversible. These findings highlight the potential of converting sugarcane bagasse via CBP, pointing out performance limitations that must be addressed. (AU)

• FAPESP's process: 21/05398-9 - Fermentation of lignocellulose by thermophilic bacteria at high solids concentration: diagnostic experiments aimed at identifying factors that diminish performance at high solids
• Grantee: Isabela Uematsu Zambello
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 21/11492-8 - Fermentation of lignocellulose by thermophilic bacteria at high solids concentration
• Grantee: Isabela Uematsu Zambello
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• FAPESP's process: 18/25682-0 - Advanced second generation biofuels laboratory
• Grantee: Lee Howard Lynd
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - SPEC