title: Isolation and characterization of a new cellulosome-producing Clostridium thermocellum strain.
abstract: The anaerobic thermophilic bacterium, Clostridium thermocellum, is a potent cellulolytic microorganism that produces large extracellular multienzyme complexes called cellulosomes. To isolate C.                         thermocellum organisms that possess effective cellulose-degrading ability, new thermophilic cellulolytic strains were screened from more than 800 samples obtained mainly from agriculture residues in Thailand using microcrystalline cellulose as a carbon source. A new strain, C. thermocellum S14, having high cellulose-degrading ability was isolated from bagasse paper sludge. Cellulosomes prepared from S14 demonstrated faster degradation of microcrystalline cellulose, and 3.4- and 5.6-fold greater Avicelase activity than those from C. thermocellum ATCC27405 and JW20 (ATCC31449), respectively. Scanning electron microscopic analysis showed that S14 had unique cell surface features with few protuberances in contrast to the type strains. In addition, the cellulosome of S14 was resistant to inhibition by cellobiose that is a major end product of cellulose hydrolysis. Saccharification tests conducted using rice straw soaked with sodium hydroxide indicated the cellulosome of S14 released approximately 1.5-fold more total sugars compared to that of ATCC27405. This newly isolated S14 strain has the potential as an enzyme resource for effective lignocellulose degradation.
authors.affiliation: Post-harvest Science and Technology Division, Japan International Research Center for Agricultural Sciences, 1-1 Ohwashi, Tsukuba, Ibaraki, Japan.
authors.forename: Chakrit
authors.initials: C
authors.lastname: Tachaapaikoon
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kosugi
authors.forename: Patthra
authors.initials: P
authors.lastname: Pason
authors.forename: Rattiya
authors.initials: R
authors.lastname: Waeonukul
authors.forename: Khanok
authors.initials: K
authors.lastname: Ratanakhanokchai
authors.forename: Khin Lay
authors.initials: KL
authors.lastname: Kyu
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Arai
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Murata
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Mori
mesh_terms: D001421:Bacteria, Anaerobic / Q000201:enzymology / Q000235:genetics; D002482:Cellulose / Q000378:metabolism; D044603:Cellulosomes / Q000201:enzymology* / Q000648:ultrastructure; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D048013:Acetivibrio thermocellus / Q000201:enzymology* / Q000235:genetics; D004926:Escherichia coli; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism*; D006868:Hydrolysis; D008031:Lignin / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D012275:Oryza / Q000378:metabolism; D012329:RNA, Bacterial / Q000096:biosynthesis / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000096:biosynthesis / Q000235:genetics; D012722:Sewage / Q000382:microbiology; D013785:Thailand; D014866:Waste Products
chemical_list: D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D014866:Waste Products; C036909:lignocellulose; D002482:Cellulose; D008031:Lignin; C027433:bagasse; D006026:Glycoside Hydrolases