Degradation of the Herbicide Atrazine by the Soil Mycelial Fungus INBI 2-26 (–), a Producer of Cellobiose Dehydrogenase

• Published in: Applied biochemistry and microbiology 2004-05, Vol.40 (3), p.285-290
• Main Authors: Khromonygina, V. V., Saltykova, A. I., Vasil'chenko, L. G., Kozlov, Yu. P., Rabinovich, M. L.
• Format: Article
• Language: English
• Subjects: Atrazine; Bacteria; Dehydrogenase; Herbicides; Microbiology
• ISSN: 0003-6838; 1608-3024
• DOI: 10.1023/B:ABIM.0000025953.93099.a9

Nonsporulating mycelial fungi producing cellobiose dehydrogenase (CDH) and isolated from soils of South Vietnam with a high residual content of dioxins are capable of growing on a solid medium in the presence of high atrazine concentrations (to 500 mg/l). At 20 and 50 mg/l atrazine, the area of fungal colonies was 1.5-1.2-fold larger, respectively, than the control colonies of the same age, whereas development of the colonies at 500 mg/l atrazine was delayed by 5 days, compared with controls grown in the absence of atrazine. Surface cultivation of the fungus on a minimal medium with glucose as a sole source of carbon and energy decreased the initial concentration of atrazine (20 mg/l) 50 times in 40 days; in addition, no pronounced sorption of atrazine by mycelium was detected. This was paralleled by an accumulation in the culture medium of extracellular CDH; atrazine increased the synthesis of this enzyme two- to threefold. Accumulation of β-glucosidase (a mycelium-associated enzyme) and cellulases preceded the formation of CDH.[PUBLICATION ABSTRACT]