title: Purification and characterization of two low molecular weight endoglucanases produced by Penicillium occitanis mutant Pol 6.
abstract: Two endoglucanases (EGs), EG A and EG B, were purified to homogeneity from Penicillium occitanis mutant Pol 6 culture medium. The molecular weights of EG A and EG B were 31,000 and 28,000 kDa, respectively. The pI was about 3 for EG A and 7.5 for EG B. Optimal activity was obtained at pH 3.5 for both endoglucanases. Optimal temperature for enzyme activity was 60 degrees C for EG A and 50 degrees C for EG B. EG A was thermostable at 60 degrees C and remained active after 1 h at 70 degrees C. EGs hydrolyzed carboxymethylcellulose, phosphoric acid swollen cellulose, and beta-glucan efficiently, whereas microcrystalline cellulose (Avicel) and laminarin were poorly hydrolyzed. Only EG B showed xylanase activity. Furthermore, these EGs were insensitive to the action of glucose and cellobiose but were inhibited by the divalent cations Hg2+, Co2+, and Mn2+.
authors.affiliation: National School of Engineers of Sfax, BP W 3038 Sfax Cedex, Tunisia. semiaellouze@yahoo.fr
authors.forename: Semia Ellouz
authors.initials: SE
authors.lastname: Chaabouni
authors.forename: Tahar
authors.initials: T
authors.lastname: Mechichi
authors.forename: Ferid
authors.initials: F
authors.lastname: Limam
authors.forename: Nejib
authors.initials: N
authors.lastname: Marzouki
mesh_terms: D002266:Carboxymethylcellulose Sodium / Q000378:metabolism; D002413:Cations, Divalent / Q000737:chemistry; D002480:Cellulase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D002482:Cellulose / Q000378:metabolism; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D005936:Glucans; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D007700:Kinetics; D008970:Molecular Weight; D009154:Mutation; D010407:Penicillium / Q000201:enzymology* / Q000235:genetics; D011134:Polysaccharides / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature; D014990:Xylans / Q000378:metabolism; D047071:beta-Glucans / Q000378:metabolism
chemical_list: D002413:Cations, Divalent; D005936:Glucans; D011134:Polysaccharides; D014990:Xylans; D047071:beta-Glucans; D002482:Cellulose; C008247:laminaran; D002480:Cellulase; D002266:Carboxymethylcellulose Sodium