Ideal conditions of microwave-assisted acid pretreatment of sugarcane straw allow fermentative butyric acid production without detoxification step

Author(s)

Fonseca, Bruna Constante ^[1] ; Reginatto, Valeria ^[1] ; Carlos Lopez-Linares, Juan ^{[2, 3]} ; Lucas, Susana ^{[2, 3]} ; Teresa Garcia-Cubero, M. ^{[2, 3]} ; Coca, Monica ^{[2, 3]}

Affiliation

^[1] Univ Sao Paulo, Dept Chem, Av Bandeirantes 3900, BR-14040901 Ribeirao Preto - Brazil

^[2] Univ Valladolid, Sch Ind Engn, Dept Chem Engn & Environm Technol, Dr Mergelina S-N, Valladolid - Spain

^[3] Univ Valladolid, Inst Sustainable Proc, Valladolid - Spain

• Document type: Journal article
• Source: Bioresource Technology; v. 329, JUN 2021.
• Web of Science Citations: 5

Abstract

Sugarcane straw (SCS) was pretreated with dilute sulfuric acid assisted by microwave to magnify fermentable sugars and to minimize the concentration of inhibitors in the hydrolysates. The optimum conditions for maximum recovery of sugars were 162 ?C and 0.6% (w/v) H2SO4. The low level of inhibitors, such as acetate (2.9 g/L) and total phenolics (1.4 g/L), in the SCS slurry from the pretreatment stage allowed the enzymatic hydrolysis and fermentation steps to occur without detoxification. Besides consuming the total sugar content (31.0 g/L), Clostridium beijerinckii Br21 was able to use acetate from the SCS hydrolysate, to give butyric acid at high conversion factor (0.49 g of butyric acid /g of sugar). The optimized pretreatment conditions spared acid, time, and the detoxification stage, making bio-butyric acid production from SCS extremely attractive. (AU)

• FAPESP's process: 18/00789-7 - Obtaining fuels, products, and energy from agroindustrial waste in biological and bioelectrochemical systems: a contribution to bioeconomy.
• Grantee: Valeria Reginatto Spiller
• Support Opportunities: Regular Research Grants