title: Comparison of microbial communities during the anaerobic digestion of Gracilaria under mesophilic and thermophilic conditions.
abstract: Mesophilic and thermophilic anaerobic digesters (MD and TD, respectively) utilizing Gracilaria and marine sediment as the substrate and inoculum, respectively, were compared by analyzing their performances and microbial community changes. During three successive transfers, the average cumulative methane yields in the MD and TD were 222.6 ± 17.3 mL CH4/g volatile solids (VS) and 246.1 ± 11 mL CH4/g VS, respectively. The higher hydrolysis rate and acidogenesis in the TD resulted in a several fold greater accumulation of volatile fatty acids (acetate, propionate, and butyrate) followed by a larger pH drop with a prolonged recovery than in the MD. However, the operational stability between both digesters remained comparable. Pyrosequencing analyses revealed that the MD had more complex microbial diversity indices and microbial community changes than the TD. Interestingly, Methanomassiliicoccales, the seventh methanogen order was the predominant archaeal order in the MD along with bacterial orders of Clostridiales, Bacteriodales, and Synergistales. Meanwhile, Coprothermobacter and Methanobacteriales dominated the bacterial and archaeal community in the TD, respectively. Although the methane yield is comparable, both MD and TD show a different profile of pH, VFA and the microbial communities.
authors: Marine Biotechnology Research Division, Korea Institute of Ocean Science and Technology, PO Box 29, Ansan, 15627, Republic of Korea.|Korea University of Science and Technology, 217 Gajunro, Yuseong-gu, Daejeon, 34113, Republic of Korea.
authors: Aqil
authors: A
authors: Azizi
authors: Marine Biotechnology Research Division, Korea Institute of Ocean Science and Technology, PO Box 29, Ansan, 15627, Republic of Korea.|Korea University of Science and Technology, 217 Gajunro, Yuseong-gu, Daejeon, 34113, Republic of Korea.
authors: Wonduck
authors: W
authors: Kim
authors: Marine Biotechnology Research Division, Korea Institute of Ocean Science and Technology, PO Box 29, Ansan, 15627, Republic of Korea. jlee@kiost.ac.kr.|Korea University of Science and Technology, 217 Gajunro, Yuseong-gu, Daejeon, 34113, Republic of Korea. jlee@kiost.ac.kr.
authors: Jung Hyun
authors: JH
authors: Lee
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria / Q000145:classification / Q000302:isolation & purification*; D061249:Batch Cell Culture Techniques; D044822:Biodiversity; D019149:Bioreactors / Q000382:microbiology; D019605:Euryarchaeota / Q000145:classification / Q000302:isolation & purification*; D005232:Fatty Acids, Volatile / Q000032:analysis*; D019015:Geologic Sediments / Q000382:microbiology*; D044724:Gracilaria / Q000382:microbiology*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008697:Methane / Q000032:analysis*; D059013:Microbial Consortia; D013696:Temperature; D062065:Wastewater
chemical_list: D005232:Fatty Acids, Volatile; D008697:Methane; D062065:Wastewater
keywords: Anaerobic digestion; Gracilaria; Mesophilic; Microbial community; Thermophilic