title: Efficient dye decolorization and production of dye decolorizing enzymes by the basidiomycete Thanatephorus cucumeris Dec 1 in a liquid and solid hybrid culture.
abstract: Thanatephorus cucumeris Dec 1, a basidiomycete, is a promising decomposer of several xenobiotics. Air-membrane surface bioreactor culture (AMS culture), a hybrid between solid-state and submerged culture, was used for Dec 1 growth. The optimum temperature for AMS culture (25 degrees C) was lower than that for submerged culture (30 degrees C). Fungal growth was almost the same in AMS culture as in submerged culture at optimum temperatures. However, protein secretion, dye decolorizing peroxidase (DyP) activity, and aryl alcohol oxidase activity, were 18-, 233-, and 36.5-fold higher in AMS culture than in submerged culture, respectively, indicating that AMS culture of Dec 1 was superior to submerged culture. In in vivo dye decolorization tests, 13 of 16 dyes were decolorized by more than 90% within 10 days. Interestingly, under AMS culture, a biofilm was formed; biofilm formation was not, however, essential for DyP and manganese dependent peroxidase (MnP) activities. Although the correlation between DyP activity and water activity was unclear, MnP activity seemed to increase in activity with decreasing water activity, even when no biofilm formation was observed.
authors.affiliation: R1-30 Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Shimokawa
authors.forename: Mitsuyo
authors.initials: M
authors.lastname: Hirai
authors.forename: Makoto
authors.initials: M
authors.lastname: Shoda
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sugano
mesh_terms: D001487:Basidiomycota / Q000201:enzymology* / Q000378:metabolism*; D018441:Biofilms; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods*; D004396:Coloring Agents / Q000737:chemistry*; D008828:Microbiological Techniques; D008855:Microscopy, Electron, Scanning; D009195:Peroxidase / Q000737:chemistry; D010544:Peroxidases / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry*
chemical_list: D004396:Coloring Agents; D014867:Water; D010544:Peroxidases; C051129:manganese peroxidase; D009195:Peroxidase