Studies on Cellulose Hydrolysis by Acetivibrio cellulolyticus.
作者： C. Roger MacKenzie , Doris Bilous , Girishchandra B. Patel
DOI: 10.1128/AEM.50.2.243-248.1985
关键词: Thermophile 、 Cellulose 、 Cellulase 、 Hydrolysis 、 Biochemistry 、 Enzyme 、 Extracellular 、 Trichoderma reesei 、 Acetivibrio cellulolyticus 、 Biology
摘要: Acetivibrio cellulolyticus extracellular cellulase extensively hydrolyzed crystalline celiuloses suchas Avicel (FMCCorp., FoodandPharmaceutical Products Div., Philadelphia, Pa.)butonlyifitwas desalted and supplemented withCa2+.TheCa2'effect was one ofincreased enzyme stability inthepresence oftheion. Although preincubation ofthecellulase complex at40°Cfor 5 hwithout addedCa2+had a negligibleeffect on endoglucanase activity or thesubseqent hydrolysis ofamorphous cellulose, thecapacity oftheenzyme to hydrolyze cellulose almostcompletely lost. Adsorption studies showedthat90% ofthe Avicel-solubilizing componentofthetotal preparation boundto2% at40°C.Underthese conditions, only15%oftheendoglucanase and25%oftheprotein present intheenzyme adsorbed tothesubstrate. Theprotein profile oftheboundenzyme, as analyzed by sodiumdodecylsulfatepolyacrylamide gelelectrophoresis, anddistinctly different fromtheprofile observed fortotal preparations. Thespecific ofA.cellulolyticus withrespect toAvicel compared withthatofcommercially available Trichoderma reesei cellulase. Inthesearch forpossible commercial sources ofcellulase, certain anaerobes havebeenthesubject ofconsiderable attention because oftheir highly efficient metabolism. Atthesametime, however, doubtshavebeen expressed abouttheusefulness ofthese organisms inthis regard ofdifficulties inobtaining enzymepreparations capable ofduplicating thehighinvivohydrolysis rates. Therehasbeenspeculation that this discrepancy mayresult fromdisruption ofahighly ordered located largely orentirely onthecell surface (5). However, attempts atgaining better understanding ofthefactors involved havebeenfrustrated byproblems encountered in fractionation andbiochemical characterization complexes. Recently, progress hasbeenmadeincharacterizing the systemofClostridium thermocellum, thermophilic anaerobe. Johnson etal.(7)reported thatCa2+anda thiol-reducing agentwererequired formaximumcellulase activity. Underoptimum thespecific of C.thermocellum wasmuchhigher thanthatobserved forcellulase produced byaerobic fungi reesei. Itwassubsequently shownbyJohnson andDemain(6) thiol-binding reagents inactivated FoodandPharamceutical Pa.)-solubilizing buthadlittle effect
sci-hub.st 参考文章(7)
E A Bayer, R Kenig, R Lamed, Adherence of Clostridium thermocellum to cellulose. Journal of Bacteriology. ,vol. 156, pp. 818- 827 ,(1983) , 10.1128/JB.156.2.818-827.1983
R. Lamed, E.A. Bayer, R. Kenig, E. Setter, Cellulosome: a discrete cell surface organelle of Clostridium thermocellum which exhibits separate antigenic, cellulose-binding and various cellulolytic activities Biotechnol. Bioeng. Symp.; (United States). ,vol. 13, ,(1983)
John D. Ferchak, Bärbel Hägerdal, E. Kendall Pye, Saccharification of cellulose by the cellulolytic enzyme system of Thermomonospora sp. II. Hydrolysis of cellulosic substrates Biotechnology and Bioengineering. ,vol. 22, pp. 1527- 1542 ,(1980) , 10.1002/BIT.260220803
D. Groleau, C. W. Forsberg, Cellulolytic activity of the rumen bacterium Bacteroides succinogenes. Canadian Journal of Microbiology. ,vol. 27, pp. 517- 530 ,(1981) , 10.1139/M81-077
U. K. LAEMMLI, Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4 Nature. ,vol. 227, pp. 680- 685 ,(1970) , 10.1038/227680A0
G. L. Pettipher, M. J. Latham, Characteristics of Enzymes Produced by Ruminococcus flavefaciens which Degrade Plant Cell Walls Microbiology. ,vol. 110, pp. 21- 27 ,(1979) , 10.1099/00221287-110-1-21
MM Bradford, None, A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding Analytical Biochemistry. ,vol. 72, pp. 248- 254 ,(1976) , 10.1016/0003-2697(76)90527-3