Integration of Subcritical Water and Enzymatic Hydrolysis to Obtain Fermentable Sugars and Second-Generation Ethanol from Sugarcane Straw

Author(s)

Oliveira, T. C. G. ; Interlandi, M. A. ; Hanlon, K. E. ; Torres-Mayanga, P. C. ; Silvello, M. A. C. ; Timko, M. T. ; Rostagno, M. A. ; Goldbeck, R. ; Forster-Carneiro, T.

• Document type: Journal article
• Source: BioEnergy Research; v. 15, n. 2, p. 12-pg., 2021-04-17.

Abstract

Converting the chemical and biologically resistant structure of cellulosic biomass into useful products is a technological and economic challenge. The use of sustainable and efficient conversion technology sustainably has been gaining prominence. This work aimed to evaluate the integration of subcritical water hydrolysis (SWH) and enzymatic hydrolysis of sugarcane straw to obtain fermentable products and second-generation ethanol. SWH was conducted under semi-continuous conditions at 200 degrees C, 5 mL/min, and a 19-min retention time. Enzymatic hydrolysis using an enzyme blend produced simple sugars that were evaluated for fermentation using two strategies: (i) Saccharomyces cerevisiae SA-1; and (ii) co-culture of S. cerevisiae SA-1 and Scheffersomyces stipitis NRRLY-7124. Integrating subcritical water and enzymatic hydrolysis resulted in greater fermentable sugar yield (2.40 +/- 0.01 g/L of xylose and 8.9 +/- 0.6 g/L of glucose) than subcritical pre-treatment on its own. The co-culture fermentation strategy was more efficient than fermentation by S. cerevisiae on its own, resulting in 2.8 +/- 0.3 g/L of ethanol. Subcritical water hydrolysis pre-treatment disrupted the lignocellulosic matrix, leading to increased enzymatic accessibility of cellulose, with minimal formation of degradation compounds, and with minimal waste formation. Future work can optimize the hydrolysis process to increase the yield of simple sugars, increase fermentation efficiency by controlling oxygen concentration and removing acetic acid, and consequently increase the yields of second-generation ethanol. (AU)

• FAPESP's process: 19/08542-3 - Enzymatic biotechnology for the xylo-oligosaccharides production from lignocellulosic agroindustrial residues aimed the production of symbiotics
• Grantee: Rosana Goldbeck Coelho
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/05999-0 - Waste2energy: integration of the supercritical and anaerobic digestion technologies for the management of water and food waste
• Grantee: Tânia Forster Carneiro
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/14582-5 - Development of a two-dimensional extraction, separation and analysis system for evaluating the bioactivity of phytochemicals
• Grantee: Maurício Ariel Rostagno
• Support Opportunities: Research Grants - Young Investigators Grants - Phase 2
• FAPESP's process: 13/04304-4 - Development of integrated systems for the analysis of bioactive compounds in natural products employing supercritical technology
• Grantee: Maurício Ariel Rostagno
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 18/14938-4 - Waste2energy: integration of supercritical technologies and anaerobic digestion through an automated system for the production of biofuel precursors
• Grantee: Tânia Forster Carneiro
• Support Opportunities: Research Grants - Young Investigators Grants - Phase 2