The potential of yeast isolated from agricultural soil in atrazine degradation

Atrazine herbicides are the most widely used pesticides in the world and are persistent on the ground. This makes atrazine an environmental concern because it can pollute the soil and water. Yeast as a degrading agent has many advantages because of its tolerance to extreme conditions and has a good response to toxic compounds. The purpose of this study was to determine the ability of yeast isolates to degrade atrazine. The isolates used were TB1, TB2, TB3, TB4, TB5, TB6, TB7, TB8, TB9, TB10, TB11, TB12, TB13,TB14, TB15, TB16, JA1, JA2, JA3, JA4, JA5, UF1, UF3, UF5, UF7, UF8, SS4, and SSU6. Isolates were screened through clear zone measurements until the best three isolates were obtained, that are TB1, UF5, and UF7. The three isolates and control were cultured in liquid Mineral Salts Medium (MSM) with 120 µg/L atrazine addition. The percentage of atrazine degradation was tested using spectrophotometric methods and yeast cell viability using the TPC method. The results showed that all isolates were able to degrade atrazine. The type of treatment and incubation time affected the ability of atrazine degradation, with the most effective isolate was TB1 which had a degradation percentage value of 94.26% and TPC of 9.27x10⁴ CFU/mL on the 10^th day.