Optimization of volatile fatty acid production by sugarcane vinasse dark fermentation using a response surface methodology. Links between performance and microbial community composition

Author(s)

Eng, Felipe ; Fuess, Lucas Tadeu ; Bovio-Winkler, Patricia ; Etchebehere, Claudia ; Sakamoto, Isabel Kimiko ; Zaiat, Marcelo

• Document type: Journal article
• Source: SUSTAINABLE ENERGY TECHNOLOGIES AND ASSESSMENTS; v. 53, p. 12-pg., 2022-09-29.

Abstract

The recovery of volatile fatty acids (VFA) from waste and wastewaters has recently been pointed out as a promising strategy for adding value to residues, which characterizes the carboxylate platform. The exploitation of sugarcane vinasse within the carboxylate platform is still an incipient approach and has to be further investigated to determine the conditions which optimize the process. This study aimed to optimize the production of VFA (as the sum of concentrations of acetic, butyric and propionic acids) through the dark fermentation (DF) of sugarcane vinasse. A central composite design (CCD, factorial 2(2)) and response surface methodology (RSM) regarding two independent variables, namely, temperature (33-47 degrees C) and initial pH (7.1-9.9), was performed. Experiments were conducted in batch reactors using diluted vinasse (COD = 10 g L (-1)) without nutrient supplementation. The results showed that the production of VFA reached a peak of 2,980 mg L (-1) (as the sum of VFA produced), yield of 332 mg-CODVFA g 1CODtinicial and productivity of 619 mg-COD L (-1) d (1)) at 39.6.C and initial pH of 8.8. The microbial community analysis performed by 16S rRNA gene amplicon sequencing showed that organisms from the families Clostridiaceae, Enterobacteriaceae and Lachnospiraceae, and Veillonellales-Selenomonadales order prevailed during higher VFA production, whilst the presence of Desulfotomaculales and Lactobacillaceae families could be associated with VFA consumption and lactic acid production, respectively. These results provide a basis for vinasse management within the carboxylate platform context, potentially diversifying the product portfolio of sugarcane biorefineries. (AU)

• FAPESP's process: 17/00080-5 - Enhancement of energy production from sugarcane in first generation biorefineries: biodigestion as the core conversion step
• Grantee: Lucas Tadeu Fuess
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 18/12748-3 - Molecular analysis of microorganisms involved in the fatty acid volatiles and hydrogen production in the treatment of vinasse from sugarcane by anaerobic digestion
• Grantee: Felipe Eng Sánchez
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 16/21478-4 - Valorization of vinasse from sugar-cane industry by anaerobic digestion: treatment, organic acids recovery and biohydrogen production
• Grantee: Felipe Eng Sánchez
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 15/06246-7 - Biorefinery concept applied to biological wastewater treatment plants: environmental pollution control coupled with material and energy recovery
• Grantee: Marcelo Zaiat
• Support Opportunities: Research Projects - Thematic Grants