Main content area

Lactate- and acetate-based biohydrogen production through dark co-fermentation of tequila vinasse and nixtamalization wastewater: Metabolic and microbial community dynamics

García-Depraect, Octavio, Valdez-Vázquez, Idania, Rene, Eldon R., Gómez-Romero, Jacob, López-López, Alberto, León-Becerril, Elizabeth
Bioresource technology 2019 v.282 pp. 236-244
acetates, bacteria, butyrates, carbohydrates, fermentation, gas production (biological), hydrogen production, lactic acid, metabolites, microbial communities, monitoring, nixtamalization, pH, vinasse, wastewater
The aim of this work was to study the metabolic and microbial community dynamics during dark co-fermentation of 80% tequila vinasse and 20% nixtamalization wastewater (w/w). Batch co-fermentations were performed in a 3-L well-mixed reactor at 35 °C and pH 5.5. In correspondence to Illumina MiSeq sequencing and reactor monitoring, changes in metabolites and microbial communities were characterized by three main stages: (i) a first stage during which lactate and acetate producers dominated and consumed the major part of fermentable carbohydrates, (ii) a second stage in which lactate and acetate were consumed by emerging hydrogen-producing bacteria (HPB) in correlation with bioH2 (100 NmL/L-h or 1200 NmL/Lreactor) and butyrate production, and (iii) a third stage during which non-HPB outcompeted HPB after bioH2 production ceased. Altogether, the results of this study suggest that cooperative interactions between lactate producers and lactate- and acetate-consuming HPB could be attributed to lactate- and acetate-based cross-feeding interactions.