New Insights into Controlling Homoacetogenesis in the Co-digestion of Coffee Waste: Effect of Operational Conditions and Characterization of Microbial Communities

• Published in: Applied biochemistry and biotechnology 2022-04, Vol.194 (4), p.1458-1478
• Main Authors: Montoya, Alejandra Carolina Villa, da Silva Mazareli, Raissa Cristina, Delforno, Tiago Palladino, Centurion, Victor Borin, de Oliveira, Valéria Maia, Silva, Edson Luiz, Varesche, Maria Bernadete Amâncio
• Format: Article
• Language: English
• Subjects: 3-Hydroxybutyryl-CoA dehydrogenase; Abundance; Acids; Anaerobiosis; Bacteria; Batch reactors; Biochemistry; Bioreactors; Biotechnology; Butanol; Carbon dioxide; Chemical oxygen demand; Chemistry; Chemistry and Materials Science; Chromatography; Coffee; Digestion; Fermentation; Functional analysis; Fungi; Headspace; Homoacetogenesis; Hydrogen; Hydrogen production; Metabolism; Metabolites; Microbial activity; Microbiota; Microorganisms; Original Article; pH effects; Phosphopyruvate hydratase; Propionate CoA-transferase; Propionic acid; Pulp; Reactors; Relative abundance; Taxonomy
• ISSN: 0273-2289; 1559-0291
• DOI: 10.1007/s12010-021-03725-3

In this research batch reactors were operated with coffee processing waste and autochthonous microbial consortium, and a taxonomic and functional analysis was performed for phase I of stabilization of maximum H 2 production and for phase II of maximum H 2 consumption. During phase I, the reactor’s operating conditions were pH 4.84 to 8.18, headspace 33.18% to 66.82%, and pulp and husk from 6.95 to 17.05 g/L. These assays continued for phase II, with initial pH conditions of 5.8–8.1, headspace of 33.18–66.82%, and pulp and husk remaining from phase I. The highest homoacetogenesis was observed in assay 5 with pH 7.7, 40% headspace, and 15 g/L of pulp and husk (initial concentrations of phase I). A relative abundance of Clostridium 41%, Lactobacillus 20% and Acetobacter 14% was observed in phase I. In phase II, there was a change in relative abundance of 21%, 63%, and 1%, respectively, and functional genes involved with autotrophic (formyltetrahydrofolate synthase) and heterotrophic (enolase) homoacetogenesis, butanol (3-hydroxybutyryl-CoA dehydrogenase), and propionic acid (propionate CoA-transferase) were identified. This study provides a new and amplified insight into the physicochemical and microbiological factors, which can be used to propose adequate operational conditions to maximize the bioenergy production and reduce homoacetogenesis in biological reactors. Graphical abstract