Record Details
Field | Value |
---|---|
Title | The decomposition of 2-chloro-4-ethylamino-6-isopropylamino-S-triazine (atrazine) and related s-triazine herbicides by soil microorganisms |
Names |
Duke, William B.
(creator) Furtick, William R. (advisor) |
Date Issued | 1964-05-06 (iso8601) |
Note | Graduation date: 1964 |
Abstract | Atrazine, atratone and ametryne are asymmetric s-triazine herbicides used pre- and post-emergence on many crops. Under conditions unfavorable for microbial activity, these compounds may persist in the soil for long periods of time. This study was conducted to determine the influence of the soil microflora upon atrazine, atratone and ametryne and to isolate microorganisms that were capable of utilizing these compounds as sole sources of energy. The relative rates of utilization of these compounds by isolated microorganisms were also studied. Woodburn silty clay loam soil was brought from the field and separate samples were treated with each of the herbicides. The samples were incubated for one and one-half months before use. Soil extracts were prepared from each of the incubated samples. Sterile Woodburn silty clay loam soil was treated with atrazine, atratone or ametryne and inoculated with a soil extract from the same incubated treatment. Carbon dioxide evolution was higher from those soil samples treated with the herbicides and inoculated with the soil extracts than from untreated soil inoculated with the same soil extracts. A soil perfusion apparatus was used to obtain microorganisms capable of utilizing atrazine and atratone as energy sources. Two microorganisms, identified as Penicillium sp. and Bacillus sp., were isolated on inorganic medium containing atrazine as a sole source of carbon. Carbon dioxide evolution from soil inoculated with Penicillium sp. and treated with atrazine, was significantly different from endogenous respiration. The addition of glucose increased the decomposition of atrazine by Penicillium sp. When atrazine was present as a substrate, oxygen uptake by Bacillus sp. increased significantly above endogenous respiration. Peptone and yeast extracts were shown to be more effectively utilized by these organisms. A Psetrdomonas sp. was isolated on inorganic medium containing atratone as a sole source of carbon. Oxygen uptake by this organism was shown to significantly increase when atratone was supplied as a substrate. However, it was shown that peptone and yeast extract were more effectively utilized by this organism. A yeast, Torulopsis sp., capable of growing on inorganic medium containing ametryne as a sole source of carbon, was isolated from Woodburn silty clay loam. Oxygen uptake by this organism was shown to significantly increase above endogenous respiration when ametryne was added as a substrate. Ametryne was more effectively utilized as a substrate than either peptone or yeast extract. |
Genre | Thesis/Dissertation |
Topic | Herbicides |
Identifier | http://hdl.handle.net/1957/48561 |