Microbial Degradation of Herbicides in Sugarcane Cultivation: A Study on Eradicane- and Tebuthiuron-Tolerant Bacteria

Abstract

Soil pollution mitigation strategies encompass diverse methodologies such as biological decomposition emerging as a promising approach due to the effectiveness of microorganisms, particularly natural bacteria. This study delves into the isolation and characterization of herbicide-tolerant bacteria in sugarcane fields during 2023–2024, with an emphasize on Eradicane and Tebuthiuron herbicides. Total number of 26 bacterial strains grown on SSM culture medium containing 3% v/v of herbicide were identified. According to biochemical and molecular assays, 19 bacterial isolates were associated with Tebuthiuron, and seven with Eradicane. The genus Pseudomonas was frequently identified with the species of P. aeruginosa (Schroeter) Migula and P. glycinae (Jia) for Tebuthiuron tolerance, and P. azotoformans Iizuka and Komagata and P. lactis for Eradicane tolerance. The highest minimum inhibitory concentration (MIC) for Eradicane was observed for P. azotoformans (220 µL/mL), while the lowest MIC was found for P. lactis (215 µL/mL). Conversely, Tebuthiuron exhibited the highest MIC against P. glycinae (185 µL/mL) and the lowest MIC against P. aeruginosa (150 µL/mL). Analysis of bacterial population growth curves indicated the P. azotoformans efficacy against Eradicane and P. aeruginosa against Tebuthiuron. Glucose utilization showed uniform growth across the bacteria, while P. glycinae exhibited the highest growth containing ammonium nitrate. These findings underscore the potential of herbicide-tolerant bacteria to facilitate bioremediation strategies for soil pollution mitigation in sugarcane fields, offering valuable insights for the advancement of sustainable agricultural practices.