Evidence of Fungicides Degradation by Rhizobia


Fungicides which are not easily degradable have the greatest adverse effects on soil microbes. These pesticides negatively affect the growth and multiplication of fungi and bacteria and consequently cause the disturbance of the natural soil microbial balance. In this study two fungicide tolerant isolates of rhizobia; clover isolate (TA1) and peanut isolate (8) were assessed in their capacity to degrade Vitavax and Rizolex. The performance of these isolates in fungicides degradation was tested using the colorimetric assay for Rizolex and the HPLC analysis for Vitavax to detect the degradation products. Using HPLC analyses, the control sample showed specific peak indicating the Vitavax presence in the medium. The specific peak did not change in the control samples throughout the experiment.With the strainTA1 the specific peak of the Vitavax fungicides started to reduce as the incubation time goes on. The Vitavax fungicide did not degrade completely after 240 hours of incubation with rhizobial isolate. The Rizolex used in this study contained blend of Thiram (active ingredient of Rizolex) and Tolcofs methyl fungicides in 1:1 ratio. The biodegradation of Rizolex in the liquid media showed the formation of two new intermediates which were released into the medium indicating the degradation of the tested fungicide by peanut rhizobial isolate No. 8 in 48 hrs of incubation 45% of this compound was degraded. This work shows that the selection of fungicides tolerant rhizobial strains is important to protect the rhizobial inoculants from the toxic effect of the pesticides.

Share and Cite:

Moawad, H. , El-Rahim, W. , Shawky, H. , Higazy, A. and Daw, Z. (2014) Evidence of Fungicides Degradation by Rhizobia. Agricultural Sciences, 5, 618-624. doi: 10.4236/as.2014.57065.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Kauffman, A.K. (1987) Applied Bioremedial Technology. Applied Biotreatment Association, Washington DC, 423-426.
[2] Racke, K.D. and Coats, J.L. (1990) Enhanced Biodegradation of Pesticides in the Environment. American Chemical Society Symposium Series, 426.
[3] Shirkot, C.K. and Gupta, K.G. (1985) Accelerated Tetramethylthiuram disulfide (TMTD) Degradation in Soil by Inoculation with TMTD-Utilizing Bacteria. Bulletin of Environmental Contamination and Toxicology, 35, 354-361.
[4] Shirkot, C.K., Shirkot, P., Dhall, S.P. and Gupta, K.G. (1990) Effectiveness of Pseudomonas aeruginosafor Detoxificaton of Tetramethylthiuramdisufide (TMTD) from Contaminated Soil. Bulletin of Environmental Contamination and Toxicology, 44, 317-324.
[5] Dick, R.E. and Quinn, J.P. (2006) Glyphosate-Degrading Isolates from Environmental Samples: Occurence and Pathways of Degradation. Applied Microbiology and Biotechnology, 43, 545-550.
[6] Sarnaik, S.S., Kanekar, P.P., Raut, V.M., Taware, S.P., Chavan, K.S. and Bhadbhade, B.J. (2006) Effect of Application of Different Pesticides to Soybean on the Soil Microflora. Journal of Environmental Biology, 27, 423-426.
[7] Fox, J.E., Gulledge, J., Engelhaupt, E., Burrow, M.E. and McLachlan, J.A. (2007) Pesticides Reduce Symbiotic Efficiency of Nitrogen-Fixing Rhizobia and Host Plants. Proceedings of the National Academy of Sciences of the United States of America, 104, 10282-10287.
[8] Gonzalez, A., González-Murua, C. and Royuela, M. (1996) Influence of Imazethapyr on Rhizobium Growth and Its Symbiosis with Pea (Pisumsativum). Weed Research, 44, 31-37.
[9] Singh, G. and Wright, D. (2002) In Vitro Studies on the Effects of Herbicides on the Growth of Rhizobia. Letters in Applied Microbiology, 35, 12-16.
[10] dos Santos, J.B., Ferreira, E.A., Kasuya, M.C.M., da Silva, A.A. and Procópio, S.O. (2005) Tolerance of Bradyrhizobiumstrains to Glyphosate Formulations. Crop Protection, 24, 543-547.
[11] Khan, H., Zeb, A., Ali, Z. and Shah, S.M. (2009) Impact of Five Insecticides on Chickpea (CicerarietinumL.) Nodulation, Yield and Nitrogen Fixing Rhizospheric Bacteria. Soil and Environment, 28, 56-59.
[12] Zahran, H.H. (1999) Rhizobium-Legume Symbiosis and Nitrogen Fixation under Severe Conditions and in an Arid Climate. Microbiology and Molecular Biology Reviews, 63, 968-989.
[13] Shafiani, S. and Malik, A. (2003) Tolerance of Pesticides and Antibiotic Resistance in Bacteria Isolated from Wastewater-Irrigated Soil. World Journal of Microbiology & Biotechnology, 19, 897-901.
[14] Tu, C.M. (1980) Effect of Fungicides on Growth of Rhizobium japonicumin Vitro. Bulletin of Environmental Contamination and Toxicology, 25, 364-368.
[15] Moorman, T.B. (1986) Effects of Herbicides on the Survival of Rhizobium japonicum Strains. Weed Science, 34, 628-633.
[16] Zablotowicz, R.M. and Reddy, K.N. (2004) Impact of Glyphosate on the Bradyrhizobiumjaponicum Symbiosis with Glyphosate-Resistant Transgenic Soybean: A Mini Review. Journal of Environmental Quality, 33, 825-831.
[17] Kaur, C., Maini, P. and Shukla, N.P. (2007) Effect of Captan and Carbendazim Fungicides on Nodulation and Biological Nitrogen Fixation in Soybean. Asian Journal of Experimental Sciences, 21, 385-388.
[18] Zawoznik, M.S. and Tomaro, M.L. (2005) Effect of Chlorimuron-Ethyl on Bradyrhizobiumjaponicum and its Symbiosis with Soybean. Pest Management Science, 61, 1003-1008.
[19] Cardina, J., Hartwig, N.L. and Lukezic, F.L. (1986) Herbicidal Effects on Growth of Rhizobia and Nodule Activity. Weed Science, 34, 338-343.
[20] Srinivas, T., Sridevi, M. and Mallaiah, K.V. (2008) Effect of Pesticides on Rhizobium and Nodulation of Green Gram Vigna radita (L.) Wilczek. The IUP Journal of Life Sciences, 2, 36-44.
[21] Tesfai, K. and Mallik, M.A.B. (1986) Effect of Fungicide Application on Soybean-Rhizobia Symbiosis and Isolation of Fungicide-Resistant Strains of Rhizobium japonicum. Bulletin of Environmental Contamination and Toxicology, 36, 819-826.
[22] Erin, M.B. and Knight, J.D. (2005) Survival of Penicillium bilaiae Inoculated on Canola Seed Treated with Vitavax RS and Extender. Biology and Fertility of Soils, 42, 54-59.
[23] Ramos, M.L.G. and Ribeiro, W.Q. (1993) Effect of Fungicides on Survival of Rhizobium on Seeds and the Nodulation of Bean (Phaseolus vulgaris L.). Plant and Soil, 152, 145-150.
[24] Dunfield, K.E., Siciliano, S.D. and Germida, J.J. (2000) The Fungicides Thiram and Captan Affect the Phenotypic Characteristics of Rhizobium leguminosarum Strain C1 as Determined by FAME and Biolog Analyses. Biology and Fertility of Soils, 31, 303-309.

Copyright © 2023 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.