title: Hydrolytic activities of extracellular enzymes in thermophilic and mesophilic anaerobic sequencing-batch reactors treating organic fractions of municipal solid wastes.
abstract: Extracellular enzymes offer active catalysis for hydrolysis of organic solid wastes in anaerobic digestion. To evidence the quantitative significance of hydrolytic enzyme activities for major waste components, track studies of thermophilic and mesophilic anaerobic sequencing-batch reactors (TASBR and MASBR) were conducted using a co-substrate of real organic wastes. During 1day batch cycle, TASBR showed higher amylase activity for carbohydrate (46%), protease activity for proteins (270%), and lipase activity for lipids (19%) than MASBR. In particular, the track study of protease identified that thermophilic anaerobes degraded protein polymers much more rapidly. Results revealed that differences in enzyme activities eventually affected acidogenic and methanogenic performances. It was demonstrated that the superior nature of enzymatic capability at thermophilic condition led to successive high-rate acidogenesis and 32% higher CH(4) recovery. Consequently, these results evidence that the coupling thermophilic digestion with sequencing-batch operation is a viable option to promote enzymatic hydrolysis of organic particulates.
authors.affiliation: Swette Center for Environmental Biotechnology, The Biodesign Institute, Arizona State University, 1001 S. McAllister Ave., Tempe, AZ 85287, USA.
authors.forename: Hyun-Woo
authors.initials: HW
authors.lastname: Kim
authors.forename: Joo-Youn
authors.initials: JY
authors.lastname: Nam
authors.forename: Seok-Tae
authors.initials: ST
authors.lastname: Kang
authors.forename: Dong-Hoon
authors.initials: DH
authors.lastname: Kim
authors.forename: Kyung-Won
authors.initials: KW
authors.lastname: Jung
authors.forename: Hang-Sik
authors.initials: HS
authors.lastname: Shin
mesh_terms: D000693:Anaerobiosis; D006868:Hydrolysis; D008049:Lipase / Q000737:chemistry*; D010447:Peptide Hydrolases / Q000737:chemistry*; D012037:Refuse Disposal; D000516:alpha-Amylases / Q000737:chemistry*
chemical_list: D008049:Lipase; D000516:alpha-Amylases; D010447:Peptide Hydrolases