A comparison of microbial characteristics between the thermophilic and mesophilic anaerobic digesters exposed to elevated food waste loadings

• Published in: Bioresource technology Vol. 152; pp. 420 - 428
• Main Authors: Guo, Xiaohui, Wang, Cheng, Sun, Faqian, Zhu, Weijing, Wu, Weixiang
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2014; Elsevier
• Subjects: anaerobic digesters; Anaerobic digestion; Anaerobiosis; Bacteria; Bacteria - genetics; Bacteria - metabolism; bacterial communities; Base Sequence; Biofuels - microbiology; Biological and medical sciences; Biological treatment of sewage sludges and wastes; Bioreactors - microbiology; Biotechnology; Communities; Elevated; Environment and pollution; Food; Food industries; Food waste; Foods; Fundamental and applied biological sciences. Psychology; Gene Library; Industrial applications and implications. Economical aspects; Methane; Methane - metabolism; methane production; Methanoculleus; methanogens; Methanosaeta; Microbial community; Microorganisms; Phylogeny; Pyrosequencing; Reactors; RNA, Ribosomal, 16S - genetics; sequence analysis; Sequence Analysis, DNA; Temperature; Thermophilic and mesophilic; Use and upgrading of agricultural and food by-products. Biotechnology; Waste Products; Wastes; Food waste; Thermophilic and mesophilic; Anaerobic digestion; Microbial community; Pyrosequencing; Sewage digester; Loading; Mesophily; Thermophily; Chemiluminescence; Microorganism; Sequencing
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2013.11.012

•Mesophilic AD performed better than thermophilic AD with increasing OLR.•Microbial communities displayed distinct structures and dynamics in MR and TR.•Mesophilic AD had greater richness and evenness of bacteria species.•Larger shifts of bacterial phylogeny were observed in MR.•Methanosaeta dominated in MR while Methanothermobacter was favored in TR. Thermophilic and mesophilic anaerobic digestion reactors (TR and MR) using food waste as substrate were compared with emphasis on microbial responses to increasing organic loading rate (OLR). At OLR ranging from 1.0 to 2.5gVSL−1d−1, MR exhibited more stable performance compared to TR in terms of methane yield. Amplicons pyrosequencing results revealed the distinct microbial dynamics in the two reactors. Primarily, MR had greater richness and evenness of bacteria species. With OLR elevated, larger shifts of bacterial phylogeny were observed in MR; Methanosaeta dominated in archaeal community in MR while Methanothermobacter and Methanoculleus were favored in TR. The high functional redundancy in bacterial community integrated with acetoclastic methanogenesis in MR resulted in its better performance; whereas delicate interactions between hydrogen-producer and hydrogenotrophic methanogens in TR were much more prone to disruption. These results are conductive to understanding the microbial mechanisms of low methane yield during food waste anaerobic digestion.