Unspecific degradation of halogenated phenols by the soil fungus Penicillium frequentans Bi 7/2

✍ Scribed by Martin Hofrichter; Friedemann Bublitz; Wolfgang Fritsche

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 551 KB
• Volume: 34
• Category: Article
• ISSN: 0233-111X
• DOI: 10.1002/jobm.3620340306

✦ Synopsis

Resting phenol-grown mycelia of the fungus Penicillium freyuentuns strain Bi 712 were shown to be capable of metabolizing various monohalogenated phenols as well as 3,4-dichlorophenol. 2.4.dichlorophenol could be metabolized in the presence of phenol as cosubstrate. In the first degradation step the halogenated phenols were oxidized to the corresponding halocatechols. Halocatechols substituted in puru-position (4-halocatechols) were further degraded under formation of 4-carboxymethylenbut-2-en-4-olide. A partial dehalogenation took place splitting the ring system. 3-Halocatechols were cleaved to 2-halomuconic acids as dead end metabolites without a dehalogenation step. Dichlorophenols were only transformed to the corresponding catechols. In addition 3,5-dichlorocatechol was 0-methylated to give two isomers of dichloroguaiacol. The halogenated catechols with the exception of 4-fluorocatechol partly polymerized oxidatively in the culturc fluid to form insoluble dark-brown products. The degradation of halophenols are due to the action of unspecific intracellular enzymes responsible for phenol catabolism (phenol hydroxylase, catechol-1 .?-dioxygenase, muconate cycloisomerase I).