title: Production of cellobiose dehydrogenase from a newly isolated white rot fungus Termitomyces sp. OE147.
abstract: Class I cellobiose dehydrogenases (CDHs) are extracellular hemoflavo enzymes produced at low levels by the Basidiomycetes (white rot fungi). In presence of suitable electron acceptors, e.g., cytochrome c, 2,6-dichlorophenol-indophenol, or metal ions, it oxidizes cellobiose to cellobionolactone. A stringent requirement for disaccharides makes CDH also useful for conversion of lactose to lactobionic acid, an important ingredient in pharma and detergent industry. In this work, class I CDH was produced using a newly identified white rot fungus Termitomyces sp. OE147. Four media were evaluated for CDH production, and maximum enzyme activity of 0.92 international unit (IU)/ml was obtained on Ludwig medium under submerged conditions. Statistical optimization of N source, which had significant effect on CDH production, using Box-Behnken design followed by optimization of inoculum size and age resulted in an increase in activity to 2.9 IU/ml and a productivity of ~25 IU/l/h. The nearly purified CDH exhibited high activity of 26.4 IU/mg protein on lactose indicating this enzyme to be useful for lactobionic acid synthesis. Some of the internal peptide sequences bore 100 % homology to the CDH produced in Myceliophthora thermophila. The fungal isolate was amenable to scale up, and an overall productivity of ~18 IU/l/h was obtained at 14-l level.
authors.affiliation: Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, 110016, India.
authors.forename: Gupteshwar
authors.initials: G
authors.lastname: Gupta
authors.forename: Rishabh
authors.initials: R
authors.lastname: Gangwar
authors.forename: Ashwani
authors.initials: A
authors.lastname: Gautam
authors.forename: Lalit
authors.initials: L
authors.lastname: Kumar
authors.forename: Anuj
authors.initials: A
authors.lastname: Dhariwal
authors.forename: Vikram
authors.initials: V
authors.lastname: Sahai
authors.forename: Saroj
authors.initials: S
authors.lastname: Mishra
mesh_terms: D002237:Carbohydrate Dehydrogenases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D013379:Substrate Specificity; D055434:Termitomyces / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D005656:Fungal Proteins; D002237:Carbohydrate Dehydrogenases; C019859:cellobiose-quinone oxidoreductase