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1814209 
Technical Report 
Microbial metabolism of the fungicide, 2,6-dichloro-4-nitroaniline 
Vanalfen, NK 
1973 
HAPAB/73/2904 
Abstr 
2 
HAPAB. Seventeen fungi and 18 bacteria were screened for their capacity to metabolize radiolabeled 2,6-dichloro-4-nitroaniline (DCNA, dichloran) in liquid culture. Many organisms converted DCNA to six or more metabolites. Two metabolites were identified as 2,6-dichloro-p-phenylenediamine (DCPD) and 4-amino-3,5-dichloroacetanilide (ADCAA). Pseudomonas capecia and other bacteria completely metabolized DCNA within 48 hours and accumulated ADCAA as the major metabolite. Most fungi accumulated small amounts of these compounds and formed different DCNA metabolites. Low aeration favored conversion of DCNA to DCPD and ADCAA by the bacteria. The fate of DCNA in flooded soil amended with D-glucose (1%, w/w) was investigated using (SUP)14C-DCNA. After two days' incubation over 80% of the DCNA had been metabolized. No metabolic carbon dioxide from DCNA was detected during the nine day experiment. ADCAA accumulated in large amounts in the soil. Also identified as metabolites of DCNA in the soil were DCPD and one of three isomers of the azine resulting from oxidative dimerization of DCPD. The same oxiduction product was found after treatment of DCPD with horseradish peroxidase. Based on the toxicity of DCPD and ADCAA to a number of fungi sensitive to DCNA, metabolism of DCNA to these compounds appears to represent detoxication. (Author abstract by permission, abridged. Copies of the thesis are available from University Microfilms, Order No. 73-19,113. )