title: Cresols utilization by Trametes versicolor and substrate interactions in the mixture with phenol.
abstract: The ability of the white rot fungus Trametes versicolor strain 1 to degrade and utilize methylated phenols (cresols) was established for the first time in a medium not containing any other carbon components. The data obtained demonstrated the better potential of the strain to assimilate p-cresol instead of o- or m- cresol. The 0.5 g/l p-cresol provided was degraded in full after 96 h. The effect of a dual substrate mixture (0.3 g/l phenol + 0.2 g/l p-cresol) on the growth behavior and degradation capacity of the investigated strain was examined. The cell-free supernatants were analyzed by HPLC. It was established that the presence of p-cresol had not prevented complete phenol degradation but had a significant delaying effect on the phenol degradation dynamics. Phenol hydroxylase, catechol 1.2-dioxygenase and cis,cis-muconate cyclase activities were obtained in conditions of single and mixed substrates cultivation. The influence of different phenolic substrates on phenol hydroxylase activity in Trametes versicolor 1 was established. The mathematical models describing the dynamics of single substrates' utilization as well as the mutual influence of phenol and p-cresol in the mixture were developed on the bases of Haldane kinetics. The estimated interaction coefficients (I(ph/cr) = 4.72, I(cr/ph) = 7.46) demonstrated the significant inhibition of p-cresol on phenol biodegradation and comparatively low level of influence of phenol presence on the p-cresol degradation. Molecular 18S RNA gene taxonomy of the investigated strain was performed.
authors.affiliation: Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G. Bontchev Str., bl. 26, Sofia, 1113, Bulgaria. zlatkama@yahoo.com
authors.forename: Zlatka
authors.initials: Z
authors.lastname: Alexieva
authors.forename: Hyusein
authors.initials: H
authors.lastname: Yemendzhiev
authors.forename: Plamena
authors.initials: P
authors.lastname: Zlateva
mesh_terms: D001673:Biodegradation, Environmental; D003408:Cresols / Q000737:chemistry / Q000378:metabolism*; D019800:Phenol / Q000378:metabolism*; D055454:Trametes / Q000378:metabolism*
chemical_list: D003408:Cresols; D019800:Phenol; C077977:cresol