Biotransformation ofs-Triazine Herbicides and Related Degradation Products in Liquid Cultures by the White Rot FungusPhanerochaete chrysosporium

Abstract

The ability of the white rot basidiomycete Phanerochaete chrysosporium to transform s‐triazine herbicides has been investigated in laboratory experiments. The chlorinated metabolites formed during atrazine N‐dealkylations were not further transformed by the fungus, whereas hydroxy‐atrazine was converted to an unknown product. P. chrysosporium was also able to carry out the N‐dealkylation of the herbicides simazine, propazine and terbuthylazine. Herbicide metabolism was not supported by purified peroxidases. The highest rates of herbicide N‐dealkylation were obtained in liquid cultures maintained under moderate temperature allowing a long mycelium growing phase. Atrazine transformation was found to be supported by the mycelium, which contained significant amounts of microsomal cytochrome P450. Herbicide N‐dealkylation was decreased in the presence of 1‐aminobenzotriazole, in agreement with the involvement of P450 monooxygenases in atrazine metabolism. © 1997 SCI.

Biodegradation of atrazine and ligninolytic enzyme production by basidiomycete strains

“…Previous research found that atrazine degradation by Phanerochaete chrysosporium and Pleurotus ostreatus INCQS 40310 had a proportional dependence on biomass and associated enzymes [4,15,16]. Thus, a nutrient rich culture medium, allowing substantial biomass development, provides best results in terms of biodegradation [22].…”

“…Conversely, fungal biodegradation is based on oxidative-hydrolytic mechanisms and until now, the metabolic routes identified are more diverse. Fungi usually modify the molecule by sequentially removing aromatic ring substituents, with dealkylation as first step [15,16]. The resulting metabolites, such as deethylatrazine (DEA), deisopropylatrazine (DIA), deethyldeisopropylatrazine (DEA-DIA), and hydroxyatrazine (HA) still retain the aromatic ring [16,17].…”

Biodegradation and Abiotic Degradation of Trifluralin: A Commonly Used Herbicide with a Poorly Understood Environmental Fate

“…It might be assumed that it would be the ligninolytic system that attacks trifluralin (laccases and/or peroxidases), since these have been implicated in the attack on other nitroaromatics, but these fungi also contain diverse other degradative enzymes such as cytochrome p450s, which could alternatively be involved . Interestingly, both fungal and bacterial p450 enzymes are known to catalyze N -dealkylation reactions − similar to those seen in many studies on trifluralin biodegradation, and thus it is possible that p450s play a role in trifluralin degradation in pure cultures and in the field. Further studies are required to confirm this.…”

Biotransformation of PAHs by the White Rot Fungus Trametes versicolor

“…Aqueous phases were pooled prior to HPLC analysis. Aliquots (10 ml) were filtered on a Whatman GF/D prefilter and concentrated on a C18 guard column as described previously [5].…”