Key microbial communities steering the functioning of anaerobic digesters during hydraulic and organic overloading shocks

• Published in: Bioresource technology 2015-12, Vol.197, p.208-216
• Main Authors: Regueiro, Leticia, Lema, Juan M., Carballa, Marta
• Format: Article
• Language: English
• Subjects: Anaerobic digestion; Anaerobiosis; Archaea - classification; Bacteria - classification; Bacteroidetes; Bioreactors - microbiology; Continuous stirred tank reactor; Fatty Acids, Volatile - metabolism; Industrial Waste; Microbial community; Tepidimicrobium; Waste Disposal, Fluid - methods
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2015.08.076

•Feedstock changes in anaerobic co-digestion processes provokes overload shocks.•Hydraulic and organic overloads cause an increase in Bacteroidetes and Actinobacteria.•Both overloads cause drop in Syntrophomonadaceae and Pseudomonadaceae.•Tissierellaceae family only increases during the organic shock. Overloading is one of the most typical process disturbance in anaerobic digesters, resulting in volatile fatty acids (VFAs) accumulation. This work aimed to study the microbial community dynamics during hydraulic (decreasing the hydraulic retention time (HRT)) and organic (increasing the organic loading rate maintaining the HRT constant) overload shocks in anaerobic reactors treating agro-industrial wastes, as well as during the recovery period. In both cases, the organic loading rate increased from 2 to 10gCODL−1d−1, resulting in VFAs accumulation up to 9gL−1. Both overloads were correlated to an increase in Bacteroidetes and Actinobacteria phyla and with a drop in Syntrophomonadaceae and Pseudomonadaceae families. In contrast, Tissierellaceae family only increased during the organic shock. Active Archaea decreased in both overloads, going from Methanosaeta dominance to Methanosarcina prevalence. During the recovery period, Porphyromonadaceae family increased its presence and Clostridium genus recovered values prior to perturbation.