ABSTRACT

This project focuses on screening bacteria for their biodegradative potential on Haloxyl-R-methyl ester, a herbicide used in agricultural and horticultural practices. The study aims to identify bacteria capable of degrading this herbicide efficiently. Various soil-borne isolates will be screened for their ability to degrade Haloxyl-R-methyl ester, with cultures showing promising degradative potentials selected for further investigation. The selected bacteria will be cultured in a medium containing the herbicide using the shake flask method to assess the rate of degradation. Enzymes responsible for the degradation process will be identified and characterized. This research contributes to understanding the biodegradation of herbicides and offers insights into sustainable approaches for mitigating the environmental impact of herbicide residues. Herbicide use and misuse also causes selection pressure on microbes in soil and water, possibly resulting in changes to microbial processes. Hence this study hope to determine the biodegradation potential of fungi on Haloxyfop-R methyl ester is a member of the aryloxyphenoxy-propionate herbicide family. Soil samples containing Haloxyfop-R methyl ester were obtained from active farmland. Using cultural and morphological parameters the biodegradative abilities of the bacteria isolates were determined and identified. The results shows that the ph of soil soil samples ranged from 5.906 ± 0.02 to 6.174 ± 0.010. The total heterotrophic bacteria counts on NA ranged from 0.6x105 ± 0CFU/g to 8.3x105± 3.0 CFU/g, while on MSM media ranged from 0.5x105 ± 0.6CFU/g to 1.1x105 ± 0.6 CFU/g. The bacteria isolates identified were Escherichia coi, Providencia sp, Klebsiella sp, Serratia sp, Pseudomonas sp, Proteus sp.1, Proteus sp.2, Enterobacter sp. The biodegradative properties of the bacterial isolates (optical density) ranged from 0.065 to 0.08 Haloxyfop-R methyl ester after 7 days. This study therefore demonstrates the abilities of bacteria to degrade haloxyfop-R methyl ester, as such opens the door for developing methods aimed to reduce contamination by haloxyfop-R methyl ester in soil and aquatic environments.