title: Microbial community distribution and extracellular enzyme activities in leach bed reactor treating food waste: effect of different leachate recirculation practices.
abstract: This study aimed at understanding the relationship between microbial community and extracellular enzyme activities of leach bed reactor (LBR) treating food waste under different leachate recirculation practices (once per day and continuous) and liquid to solid (L/S) ratios (1:1 and 0.5:1). Microbial community analysis using PCR-DGGE revealed that Lactobacillus sp., Bifidobacter sp., and Proteobacteria were the most abundant species. Number of phylotypes was higher in LBRs with intermittent recirculation; whereas, lower number of phylotypes dominated by the key players of degradation was observed with continuous recirculation. The L/S ratio of 1:1 significantly enhanced the volatile solids removal compared with 0.5:1; however, this effect was insignificant under once a day leachate recirculation. Continuous leachate recirculation with 1:1 L/S ratio significantly improved the organic leaching (240 g COD/kgvolatile solid) and showed distinct extracellular enzyme activities suitable for food waste acidogenesis.
authors: Department of Environmental & Low-Carbon Science, School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, China; Sino-Forest Applied Research Centre for Pearl River Delta Environment and Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region.
authors: Su Yun
authors: SY
authors: Xu
authors: Sino-Forest Applied Research Centre for Pearl River Delta Environment and Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region; School of Marine and Tropical Biology, Faculty of Engineering, James Cook University, Townsville, Queensland, Australia.
authors: Obuli P
authors: OP
authors: Karthikeyan
authors: Sino-Forest Applied Research Centre for Pearl River Delta Environment and Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region.
authors: Ammaiyappan
authors: A
authors: Selvam
authors: Sino-Forest Applied Research Centre for Pearl River Delta Environment and Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region. Electronic address: jwcwong@hkbu.edu.hk.
authors: Jonathan W C
authors: JW
authors: Wong
mesh_terms: D000143:Acids / Q000378:metabolism; D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D058645:Denaturing Gradient Gel Electrophoresis; D005110:Extracellular Space / Q000201:enzymology*; D005502:Food; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012037:Refuse Disposal / Q000295:instrumentation* / Q000379:methods*; D014866:Waste Products; D014874:Water Pollutants, Chemical
chemical_list: D000143:Acids; D012336:RNA, Ribosomal, 16S; D014866:Waste Products; D014874:Water Pollutants, Chemical
keywords: Extracellular enzymes; Food waste; Hydrolysis; Leach bed reactor; Microbial community