Purification and Characterization of a Low Molecular Weight of [beta]-Mannanase from Penicillium occitanis Pol6

• Published in: Applied biochemistry and biotechnology Vol. 160; no. 4; p. 1227
• Main Authors: Blibech, Monia, Ghorbel, Raoudha Ellouz, Fakhfakh, Ines, Ntarima, Patricia, Piens, Katheleen, Bacha, Abir Ben, Ellouz Chaabouni, Semia
• Format: Journal Article
• Language: English
• Published: Totowa Springer Nature B.V 01-02-2010
• Subjects: Amino acids; Ammonium; Bacteria; Biotechnology; Enzymes; Molecular weight
• ISSN: 0273-2289; 1559-0291
• DOI: 10.1007/s12010-009-8630-z

The highest β-mannanase activity was produced by Penicillium occitanis Pol6 on flour of carob seed, whereas starch-containing medium gave lower enzymes titles. The low molecular weight enzyme was purified to homogeneity by ammonium sulfate precipitation, gel filtration, and ion-exchange chromatography procedures. The purified β-mannanase (ManIII) has been identified as a glycoprotein (carbohydrate content 5%) with an apparent molecular mass of 18 kDa. It was active at 40 °C and pH 4.0. It was stable for 30 min at 70 °C and has a broad pH stability (2.0-12.0). ManIII showed K ^sub m^, V ^sub max^, and K ^sub cat^ values of 17.94 mg/ml, 93.52 U/mg, and 28.13 s^sup -1^ with locust bean gum as substrate, respectively. It was inhibited by mannose with a K ^sub I^ of 0.610^sup -3^ mg/ml. ManIII was activated by CuSO^sub 4^ and CaCl^sub 2^ (2.5 mM). However, in presence of 2.5 mM Co^sup 2+^, its activity dropped to 60% of the initial activity. Both N-terminal and internal amino acid sequences of ManIII presented no homology with mannanases of glycosides hydrolases. During incubation with locust bean gum and Ivory nut mannan, the enzyme released mainly mannotetraose, mannotriose, and mannobiose.[PUBLICATION ABSTRACT]