title: The effect of pH on the production of chitinolytic enzymes of Verticillium fungicola in submerged cultures.
abstract: Chitinase and N-acetylhexosaminidase activities in submerged cultures of Verticillium fungicola increased up to 5-fold and 2.5-fold, respectively when the pH of the culture medium was raised from 5 to 8. SDS-PAGE and zymograms of the freeze-dried crude enzyme obtained from the cultures indicated four chitin degrading proteins of M(w) 24, 40, 55 and 63 kDa, whereas isoelectric focusing displayed the separation of three chitin degrading enzymes with isoelectric points of 4.7, 6.8 and 10, as well as two N-acetylhexosaminidases having isoelectric points of 3.2 and 13. Freeze-dried crude enzyme was characterized for its ability to produce chito-oligosaccharides from chitosans. Matrix-assisted laser desorption ionization time of flight mass spectrometry analyses revealed that monomers as well as hetero-oligomers with degree of polymerization 4 were initially the main products, whereas oligomers with degree of polymerization 2-11 were detected after extended reaction times.
authors.affiliation: Universidad Autónoma Metropolitana, Biotechnology Department, Laboratory of Biopolymers, Av. San Rafael Atlixco, No. 186, 09340 Mexico City, Mexico.
authors.forename: Laura
authors.initials: L
authors.lastname: Ramirez-Coutiño
authors.forename: Jesús
authors.initials: J
authors.lastname: Espinosa-Marquez
authors.forename: Martin G
authors.initials: MG
authors.lastname: Peter
authors.forename: Keiko
authors.initials: K
authors.lastname: Shirai
mesh_terms: D018929:Cell Culture Techniques / Q000379:methods*; D002686:Chitin / Q000378:metabolism*; D002688:Chitinases / Q000096:biosynthesis*; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007525:Isoelectric Focusing; D013347:Subcellular Fractions / Q000201:enzymology; D013997:Time Factors; D020172:Verticillium / Q000166:cytology* / Q000201:enzymology*; D001619:beta-N-Acetylhexosaminidases / Q000096:biosynthesis*
chemical_list: D002686:Chitin; D002688:Chitinases; D001619:beta-N-Acetylhexosaminidases