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LAPSE:2023.11239

Enhancing Biobased Volatile Fatty Acids Production from Olive Mill Solid Waste by Optimization of pH and Substrate to Inoculum Ratio

Yasmim A. da Fonseca, Adonai B. de Camargos, Gustavo S. M. Gomes, P. Fregulia, Silvana Q. Silva, Leandro V. A. Gurgel, Bruno E. L. Baêta

February 27, 2023

Abstract
The pH and substrate-to-inoculum ratio (S/I) are important parameters in the anaerobic fermentation of agroindustrial residues, and therefore the optimization of these two parameters is needed for a stable, efficient, and sustainable reactor operation. In this work, the parameters pH (5−9) and S/I (0.5−3 gVS gVS−1) were optimized to produce biobased volatile fatty acids (VFAs) from hydrothermally pretreated olive mill solid waste (HPOMSW). The response variables evaluated in the Doehlert design were total VFAs concentration (tVFAs) (mg L−1) and amounts (%) of isobutyric, butyric, isovaleric, and valeric acids on the VFAs profile. The pH was the variable that most influenced the mixed culture fermentation of HPOMSW, proving to be a key parameter in the process. Microbial community analyses of conditions 1 (S/I = 3 gVS gVS−1 and pH = 7) and 4 (S/I = 1.13 gVS gVS−1 and pH = 5) showed that Proteobacteria and Firmicutes accounted for more than 87% of the total microorganisms identified for both conditions. In addition, the second-order model best fitted the experimental data for the VFAs production at the desirable condition (S/I = 3 gVS gVS−1 and pH = 8).

Record ID

LAPSE:2023.11239

Keywords

anaerobic digestion, Biomass, carboxylic acids, kinetics, microbial community

Subject

Biosystems

Suggested Citation

da Fonseca YA, de Camargos AB, Gomes GSM, Fregulia P, Silva SQ, Gurgel LVA, Baêta BEL. Enhancing Biobased Volatile Fatty Acids Production from Olive Mill Solid Waste by Optimization of pH and Substrate to Inoculum Ratio. (2023). LAPSE:2023.11239

Author Affiliations

da Fonseca YA: Environmental and Chemical Technology Group, Department of Chemistry, Federal University of Ouro Preto, Campus Universitário Morro do Cruzeiro, Bauxita, s/n, Ouro Preto 35400-000, MG, Brazil [ORCID]
de Camargos AB: Environmental and Chemical Technology Group, Department of Chemistry, Federal University of Ouro Preto, Campus Universitário Morro do Cruzeiro, Bauxita, s/n, Ouro Preto 35400-000, MG, Brazil
Gomes GSM: Environmental and Chemical Technology Group, Department of Chemistry, Federal University of Ouro Preto, Campus Universitário Morro do Cruzeiro, Bauxita, s/n, Ouro Preto 35400-000, MG, Brazil
Fregulia P: U.S. Dairy Forage Research Center, Agricultural Research Service (ARS), U.S. Department of Agriculture (USDA) 1925 Linden Drive, Madison, WI 53706, USA [ORCID]
Silva SQ: Department of Biological Sciences, Federal University of Ouro Preto, Campus Universitário, Morro do Cruzeiro, Bauxita, s/n, Ouro Preto 35400-000, MG, Brazil [ORCID]
Gurgel LVA: Environmental and Chemical Technology Group, Department of Chemistry, Federal University of Ouro Preto, Campus Universitário Morro do Cruzeiro, Bauxita, s/n, Ouro Preto 35400-000, MG, Brazil [ORCID]
Baêta BEL: Environmental and Chemical Technology Group, Department of Chemistry, Federal University of Ouro Preto, Campus Universitário Morro do Cruzeiro, Bauxita, s/n, Ouro Preto 35400-000, MG, Brazil

Journal Name

Processes

Volume

Issue

First Page

338

Year

2023

Publication Date

2023-01-20

DOI:

https://doi.org/10.3390/pr11020338