Phenol and its derivatives are one of the largest groups of environmental pollutants due to their presence in many industrial effluents and broad application as antibacterial and antifungal agents. A number of microbial species possess enzyme systems that are applicable for the decomposition of various aliphatic and aromatic toxic compounds. Intensive efforts to screen species with high‐degradation activity are needed to study their capabilities of degrading phenol and phenolic derivatives. Most of the current research has been directed at the isolation and study of microbial species of potential ecological significance. In this review, some of the best achievements in degrading phenolic compounds by bacteria and yeasts are presented, which draws attention to the high efficiency of strains of Pseudomonas, Candida tropicalis, Trichosporon cutaneum, etc. The unique ability of fungi to maintain their degradation potential under conditions unfavorable for other microorganisms is outstanding. Mathematical models of the microbial biodegradation dynamics of single and mixed aromatic compounds, which direct to the benefit of the processes studied in optimization of modern environmental biotechnology are also presented.

Trametes versicolor 1 was shown to grow on phenol as its sole carbon and energy source. The culture growth and degradation ability dependence on culture medium pH value was observed. The optimal pH value of a liquid Czapek salt medium was 6.5. The investigated strain utilized completely 0.5 g/l phenol in 6 days. The dynamics of the phenol degradation process was investigated. The process was characterized by specific growth rate micromax 0.33 h(-1), metabolic coefficient k=4.4, yield coefficient Yx/s=0.23 and rate of degradation Q=0.506 h(-1). The intracellular activities of phenol hydroxylase (0.333 U/mg protein) and cis,cis-muconate lactonizing enzyme (0.41 U/mg protein) were demonstrated for the first time in this fungus. In an attempt to estimate the occurrence of gene sequences in T. versicolor 1 related to phenol degradation pathway a dot blot analysis with total DNA isolated from this strain was performed. Two synthetic oligonucleotides were used as hybridizing probes. One of the probes was homologous to the 5'end of phyA gene coding for phenol hydroxylase in Trichosporon cutaneum ATCC 46490. The other probe was created on the basis of cis,cis-muconate lactonizing enzyme coding gene in T. cutaneum ATCC 58094. The results of these investigations showed that T. versicolor 1 may carry genes similar to those of Trichosporon cutaneum capable to degrade phenol.

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.

The industry is a major source of pollution for water ecosystems. Industrial production of textile, cellulose and various chemicals is connected with synthetic dyes usage. The discharged effluents could have a hazardous influence on the environment. The biological treatment for synthetic dyes removal is a very perspective, environmentally protective and low cost approach for solution of such problems. One of the often used and very important in dyeing of cellulosic fabrics and textile industry dyes is an anthraquinone-base chlorotriazine dye, known as Reactive Blue 4.Decolorization of Reactive Blue 4 by Trametes versicolor strain 1 was investigated. The experiments were carried out with different concentrations of dye (50mg/l and 125mg/l) and glucose (1, 2 and 3%) in a medium. The enzyme activity of laccase (EC 1.10.3.2) was measured during the process of decolorization. It was shown that there is a direct correlation between the observed enzyme activity and the investigated process effectiveness. It was established that the best conditions for laccase production and decolorization of 125mg/l Reactive Blue 4 dye are in medium containing 3% glucose. In these conditions 90% Reactive Blue 4 was decolorized in 384 hours.