Active prokaryotic population dynamics exhibit high correlation to reactor performance during methane production from acid hydrolysates ofAgave tequilanavar.azulbagasse

Abstract

Aims The purpose of this study was to apply cDNA approach for the characterization of active prokaryotic community to understand microbial scenarios and performance of an AnSBR digester fed with acid hydrolysates of Agave tequilana var. azul bagasse (ATAB). Methods and Results The digester was implemented for methane production under organic loading rate (OLR) disturbances to correlate physicochemical variables with changes in abundance, diversity and population dynamics of active Bacteria and Archaea by principal components analysis (PCA). Results indicated that methane yield increased as well as active syntrophic relationships for interspecies hydrogen/formate (Anaerolinaceae‐Methanobacterium beijingense) and acetate (Anaerolinaceae‐Methanosaeta concilii) transfers at 8 g‐COD l−1 day−1. However, methane yield was negatively affected at 16 g‐COD l−1 day−1 due to the competition for acetate by active Desulfovibrio marrakechensis and volatile fatty acids inhibition. Conclusions Microbial scenarios obtained by PCA correlations indicated that methane production from acid hydrolysates of ATAB was feasible at 8 g‐COD l−1 day−1. The digester operation at higher OLR only favoured methanogenesis by the hydrogenotrophic pathway. Significance and Impact of the Study Only cDNA analysis showed Archaea population dynamics, exhibiting high correlation with physicochemical variables towards the understanding of the methanogenic digester performance during OLR disturbances.

A Comprehensive Overview of the Potential of Tequila Industry By-Products for Biohydrogen and Biomethane Production: Current Status and Future Perspectives

“…It has been previously observed that the two-stage AD of TV at low concentrations of VFAs (low OLRs) favored the acetoclastic pathway, in contrast, hydrogenotrophic methanogens enriched at high concentrations (high OLRs) [7]. This change in diversity has been also observed in an AnSBR digester fed with acid AB hydrolysates [53]. However, the opposite trend was observed during the single stage AD of TV using a pilot-scale PBR [47].…”

“…However, the opposite trend was observed during the single stage AD of TV using a pilot-scale PBR [47]. Regardless of the tequila by-product used, loss of syntrophic relationships for interspecies H 2 /HFor transfer and interspecies HAc transfer has been associated with microbial imbalance, which subsequently affects negatively bioCH 4 production [8,53]. However, in the case of multi-stage AD processes, unsuitable concentrations of hydrolytic/acidogenic bacteria in DF effluent may be quite detrimental for the granular methanogenic sludge [15].…”

Bioderived ionic liquid-based pretreatment enhances methane production from Agave tequilana bagasse

“…The methane yield obtained with this type of hydrolysates is similar to other reports using specialized reactors or similar hydrolysates. 41,42 Interestingly, the [Ch][Lys]-pretreated solids without being saccharied reached 433 mL of methane with a yield of 0.24 L CH 4 per VSS, representing a 5.4 fold compared to the untreated ATB and a 70% of the methane produced by the hydrolysate; making clear that the availability of the nutrients contained in the ATB increases considerably through pretreatment with ILs.…”

Performance and microbial analysis during long‐term anaerobic digestion of olive mill wastewater in a packed‐bed biofilm reactor

“…6 Methanosaetaceae represents only 3.2%. 55 Moreover, the metabolic activity through RNA-based analysis 56 can provide a more precise visualization of short-term dynamics of CH 4 producing population in further studies. The relative abundance of the main phylogenetic groups found within the archaeal domain, which is in accordance with the data from the rrs sequence analysis, confirms the presumable capability of the primers used for the phylogenetic classification to amplify the 16S rRNA gene sequences of the Archaea without preference or discrimination of single subgroups.…”

“…Since the number of operons coding for the 16S RNA gene can vary considerably from species to species and even within strains, moderate differences can be observed between the actual and the investigated relative abundances of microorganisms. 55 Moreover, the metabolic activity through RNA-based analysis 56 can provide a more precise visualization of short-term dynamics of CH 4 producing population in further studies.…”