Shift in Bacterial Community Structure Drives Different Atrazine-Degrading Efficiencies

Abstract

Compositions of pollutant-catabolic consortia and interactions between community members greatly affect the efficiency of pollutant catabolism. However, the relationships between community structure and efficiency of catabolic function in pollutant-catabolic consortia remain largely unknown. In this study, an original enrichment (AT) capable of degrading atrazine was obtained. And two enrichments – with a better/worse atrazine-degrading efficiency (ATB/ATW) – were derived from the original enrichment AT by continuous sub-enrichment with or without atrazine. Subsequently, an Arthrobacter sp. strain, AT5, that was capable of degrading atrazine was isolated from enrichment AT. The bacterial community structures of these three enrichments were investigated using high-throughput sequencing analysis of the 16S rRNA gene. The atrazine-degrading efficiency improved as the abundance of Arthrobacter species increased in enrichment ATB. The relative abundance of Arthrobacter was positively correlated with those of Hyphomicrobium and Methylophilus, which enhanced atrazine degradation via promoting the growth of Arthrobacter. Furthermore, six genera/families such as Azospirillum and Halomonas showed a significantly negative correlation with atrazine-degrading efficiency, as they suppressed atrazine degradation directly. These results suggested that atrazine-degrading efficiency was affected by not only the degrader but also some non-degraders in the community. The promotion and suppression of atrazine degradation by Methylophilus and Azospirillum/Halomonas, respectively, were experimentally validated in vitro, showing that shifts in both the composition and abundance in consortia can drive the change in the efficiency of catabolic function. This study provides valuable information for designing enhanced bioremediation strategies.

Interaction between a nano-formulation of atrazine and rhizosphere bacterial communities: atrazine degradation and bacterial community alterations

“…Previous studies already showed the adverse effects of ATZ on the structure of soil microbial communities after longterm exposure. [36][37][38][39][40] Here, we documented the chronic adverse effects of NPATZs on the rhizosphere bacterial communities of L. sativa. For instance, it was found that 6 months of soil treatment with ATZ decreased the diversity and evenness of the bacterial community of the soil compared to the control.…”

Correlating Biodegradation Kinetics of 2,4-Dichlorophenoxyacetic Acid (2,4-D) and 2,4,5-Trichlorophenoxyacetic Acid (2,4,5-T) to the Dynamics of Microbial Communities Originating From Soil in Vietnam Contaminated With Herbicides

“…In the latter case, the specialists may well have been outcompeted by those growing on the amendments as a result of competition for oxygen, for vitamins or for essential nutrients. Indeed, many reports indicate that indigenous microbial populations are good candidates for the breakdown of aromatic compounds that pollute the environment that they live in (Ren et al, 2015;Liu et al, 2019). More detailed studies also showed a clear correlation between expression of tfdA and cad genes involved in phenoxyacetic acid degradation and mineralisation rate of these herbicides along with the evolution of the soil microbial communities (Baelum et al, 2008;Ditterich et al, 2013).…”

Impact of Paenarthrobacter ureafaciens ZF1 on the soil enzyme activity and microbial community during the bioremediation of atrazine-contaminated soils

“…Soil and water pollution by atrazine is a persistent problem worldwide, and poses a considerable threat to the health of soil ecosystem, and adversely influences the soil biological processes by altering soil enzymatic activities, soil microbial population and community diversity [ 45 – 47 ]. Therefore, it is crucial to find a practical solution for the remediation of atrazine -contaminated environments.…”