The Penicillium strain Bi 712 utilized phenol, catechol, resorcinol, hydroquinone, pyrogallol, hydroxyhydroquinone, phloroglucinol, m-and p-cresol, orcinol, 4-methylcatechol, 4-methoxyphenol, 4-aminophenol, benzyl alcohol, benzoic acid, 2-, 3and 4-hydroxybenzoic acid, anthranilic acid, protocatechuic acid and gallic acid as sole sources of carbon and energy. The central metabolites catechol, protocatechuic acid and hydroxyquinone could be determined by HPLC with diode-array detection. Pathways for the degradation of aromatic substances were proposed.
Most of the information on metabolism of aromatic substances by fungi were reported for yeasts (NEUJAHR and VARGA 1970, ANDERSON and DAGLEY 1980, POWLOWSKI and DAGLEY 1985, HASEGAWA et al. 1990). The respective knowledge about filamentous fungi is limited. ANSELMO and NOVAIS (1984) and ANSELMO et al. (1985) described the growth of Fusarium flocciferum with phenol as sole carbon source. The utilization of benzoic and phenoxyacetic acids by Aspergillus niger was reported by SHAILUBHAI and SAHASRABUDHE (1983), SHAILUBHAI et at. (1984) and SARASHABUDHE et al. (1985). A comparative study on the abilities of phytopathogenic and saprophytic fungi in dissimilating aromatic substances was published by BOOMI-NATHAN and MAHADEVAN (1989). We reported previously that Penicillium sp. Bi 712 isolated from a contaminated soil utilized phenol as sole carbon source and cometabolized chloro-and nitrophenols (HOFRICHTER et al. 1992(HOFRICHTER et al. , 1993)). The degradation of phenol occurs via the ortho-pathway under formation of /I-ketoadipate. The strain has an unspecific phenol hydroxylase which oxidizes a wide range of phenolic substrates (HOFRICHTER etal. 1992).
Materials and methods
Source of organism:
The strain Penicillium sp. Bi 712 used in the present studies was isolated from a contaminated soil as described earlier (HOFRICHTER et a/. 1992(HOFRICHTER et a/. , 1993)).
Culture conditions: 500 mg of the aromatic substances were filter sterilized and added to sterile CZAPEK-DOX medium, instead of sucrose. 100 ml of the medium were inoculated with 1 ml of a spore suspension in 500-ml flasks and incubated in the dark at 24 "C on a rotary shaker (160 rpm). Mycelial growth was estimated by dry weight measurement.
Physical and chemical analyses:
A MERCK-HITACHI HPLC (L-6200/D-2500) with a variable wave length absorbance detector (UV-4200) operating at 280 nm and fitted with a MERCK LiChrospher 5 pm RP-18 column (125 x 4.6 mm ID) was used to detect the various aromatic compounds by using