Fungal Transformations

FIGURE 8.19 Biotransformation of 7-methylbenz[a]anthracene by Cunninghamella elegans. 

FIGURE 8.20 Alternative pathways for the biotransformation of fluoranthene by Cunninghamella elegans. 

There are two issues that recur in fungal transformations, and these have been extensively documented  

Similar experiments with 1-methyl- and 2-methylnaphthalene involved oxidation of the methyl group to hydroxymethyl and carboxyl groups (Cemiglia et al. 1984a,b). 

FIGURE 8.22 Products produced by fungal transformation of benzo[a]pyrene. (From Neilson, A.H. and Allard, A.-S. The Handbook of Environmental Chemistry, Springer, 1998. With permission.) 

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The degradation of BTEX both individually or in admixture has been shown in a lignindegrading white-rot fungus under nonlignolytic conditions, and was confirmed with ring-labeled toluene (Yadav and Reddy 1993). Interest in fungal transformation of PAHs is noted in the next part of this chapter, and illustrative examples of the hydroxylation of monocyclic arenes include the following (Smith and Rosazza 1983) ... 

Pothuluri V, JP Freeman, FE Evans, CE Cerniglia (1990) Fungal transformation of fluoranthene. Appl Environ Microbiol 56 2974-2983. 

Nonsteroidal anti-inflammatory agents are used extensively as nonprescription drugs, and residues of these compounds have been detected ubiquitously in WWTP effluents at the pg L 1 levels, and they also frequently occur at the ng L 1 level in the aquatic environment (see [2], this volume). As a result, many researchers have focused on the degradation of these pharmaceuticals, which are one of the most studied groups of therapeutic agents in terms of fungal transformation. 

The fungal transformation of estrogens, by enzymes or cells, seems to produce metabolites with reduced estrogenic activity in short periods, usually days or even few hours. However, only oligomeric products have been identified in enzymatic processes and a lack in the identification of metabolites derived from whole cell fungal systems is still observed. 

More recently, the fungal transformation of (-)-menthol by Cephalosporium aphidicola was reported [111]. Incubation of (-)-menthol with this fungus for 12 days yielded four new metabolites, 10-acetoxymenthol, 4a-hydroxymenthol, 3a-hydroxymenthol, and 10-hydroxymenthol and two known compounds identified as 7-hydroxymenthol and 9-hydroxymenthol. 

Gadd, G. M. Sayer, J. A. (2000). Fungal transformations of metals and metalloids. In Environmental Microbe-Metal Interactions, ed. D. R. Lovley. Washington, DC American Society for Microbiology, pp. 237-56. 

Antimony has been suggested to be a causal factor in sudden infant death syndrome, since fungal transformation of fire retardants containing antimony in cot mattresses will lead to the formation of stibine (SbHs). However, the involvement of stibine in cot death is most unlikely (5,6). 

Sebek, O.K. (1983) Fungal transformations as a useful method for the synthesis of organic compounds. Mycologia, 75, 383-394. 

Parrish, F. W. 1977. Fungal transformation of 2,4-dinitrotoluene and 2,4,6-trinitrotoluene. Appl. Environ. Microbiol. 34 232-233. 

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