Published online by Cambridge University Press: 12 June 2017
The herbicide l-(2-methylcyclohexyl)-3-phenylurea (siduron) suppressed the growth of soil bacteria, Azotobacter sp. and Chlorella vulgaris whereas siduron had no effect on actinomycetes, filamentous fungi, soil ciliates and other algae. Siduron had no effect upon the growth of Thiobacillus thioparus, Euglena gracilis, and Streptomyces griseus. The degradation product, 2-methylcyclohexylamine (hereinafter referred to as 2-MCHA) suppressed the growth of Aztobacter chroococcum and soil ciliates. Aniline, another degradation product of siduron, depressed the growth of Aspergillus versicolor and A. fischeri; however, A. ochraceus, A. candidus, A. clavatus, A. nidulans, A. flavus, Botrytis cinerea, and Rhizopus nigricans were not affected. None of these fungi was influenced in growth by 2-MCHA. Streptomyces griseus grew significantly less in the presence of aniline. The growth of Chlamydomonas pyrenoidosa, C. radiata, Anabaena catenula, and Rhizobium leguminosarum were not influenced by 10 ppm aniline or 10 ppm 2-MCHA.