초록
<P><B>Abstract</B></P> <P>The objective of this study was to evaluate the fermentation conditions that led to the optimization of H<SUB>2</SUB> production from coffee waste (wastewater, pulp and husk) and the taxonomic and functional characterization of autochthonous microorganisms. Assays in batch reactors with microbial consortium bioaugmentation (bacteria and fungi) evaluated the pH (4.82–8.18), pulp and husk concentration (6.95–17.05 g/L) and headspace factor (33.18–66.82%) by means of rotational central composite design and response surface. Operating conditions in the reactor optimized for 3.04 LH<SUB>2</SUB>/Ld were at pH 7.0, 7 g/L pulp and husk and 30% headspace. The main metabolites observed were butyric acid (3838 mg/L), isobutyric acid (506 mg/L), methanol (226 mg/L) and butanol (156 mg/L). <I>Clostridium</I> sp. (87.9%), <I>Lactobacillus</I> sp. (1.7%), <I>Kazachstania</I> sp. (18.6%) and <I>Saccharomyces</I> sp. (16.3%) were the main genera identified in the optimized reactor, which had functional gene diversity for H<SUB>2</SUB> production, alcoholic fermentation, cellulose degradation, lignin, hemicellulose and phenol.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Bio-H<SUB>2</SUB> from coffee wastewater and pulp/husk using autochthonous microorganisms. </LI> <LI> Optimization of pH, headspace and coffee pulp/husk concentration. </LI> <LI> Functional genes related with H<SUB>2</SUB> production and lignocellulose degradation. </LI> <LI> Microbial consortium with <I>Clostridium</I> (88%) and <I>Kazachstania</I> (19%). </LI> <LI> H<SUB>2</SUB>, organic acids and alcohols production pathway from coffee waste. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>