Download or read book Microbial Communities and Their Enzymes Involved in Biodegradation of Herbicides and Dioxins written by and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the Vietnam war from 1961 to 1971, the United States military defoliated trees and plants using approximately 80 million liters of the herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), the last of which appeared to be contaminated with trace amounts of the highly toxic dioxin congener 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). Until recently, Bien Hoa airbase in South Vietnam was a highly contaminated hotspot where soils and sediments in the vicinity of the site were polluted with high concentrations of herbicides and dioxins due to large spills. The aim of the studies was to correlate the composition and dynamics of microbial communities originating from soils contaminated with herbicides and dioxins at Bien Hoa airbase in Vietnam to the biodegradation of 2,3,7,8-TCDD, 2,4-D and 2,4,5-T in order to obtain a better understanding of the role of key bacteria participating in their biodegradation, and to get insight into the best conditions for bioremediation. Our general approach was i) to enrich microbial communities from dioxin and herbicide polluted soil in Vietnam under defined conditions and to follow their community compositions over time using high throughput 16S rRNA gene profiling using the Illumina platform, and ii) to measure the degradation of 2,3,7,8-TCDD or the herbicides 2,4-D and 2,4,5-T using the DR-CALUX® bioassay or LC-MS/MS in parallel. A more specific approach was the isolation and characterization of bacteria and fungi that were dominant in some of the enrichments and which showed breakdown of 2,3,7,8-TCDD or the herbicides 2,4-D and 2,4,5-T when grown in isolation. The inspection of the genomes of some of the isolated bacterial species provided a more detailed insight in their genetic and metabolic potential to degrade these xenobiotics. Chapter 2 determined the correlation of the microbial community structure potentially contributing to 2,3,7,8-TCDD biodegradation.