Effect Of Sodium Dodecyl Sulfate On Microbial Community Structure And Function In Lake-terrestrial Ecotone

As the most widely used surfactant in the world,sodium dodecyl sulfate(SDS)has an inhibitory effect on environmental microorganisms.Since the outbreak of COVID-19,more sodium dodecyl sulfate has been discharged into natural water through lake-terrestrial ecotone,which has caused a non-negligible impact on soil microbial activity and material circulation in lake-terrestrial ecotone.The migration and degradation of SDS in lake-terrestrial ecotone were analyzed by measuring the concentration change of SDS in water and soil.16 S r RNA high-throughput sequencing was used to analyze the changes of diversity,community structure,functional genes and metabolic pathways of lake-terrestrial ecotone microorganisms under the influence of SDS,and to explore the response mechanism of lakeside microorganisms to SDS under different health states.The main conclusions include:(1)After SDS entered the water-soil-plant and animal system in lake-terrestrial ecotone,part of SDS remained in the water,and a large amount of SDS was adsorbed by the soil in lake-terrestrial ecotone.Most of the SDS adsorbed in the soil were degraded by microorganisms,and a small amount of SDS were degraded chemically.(2)SDS into the soil of lake-terrestrial ecotone had different effects on microbial diversity,community structure and functional genes.The healthy lake-terrestrial ecotone had the best degradation effect on SDS,and the degradation rate reached97.31% within 6 days.The microbial diversity did not change much in the healthy lake-terrestrial ecotone,and the microbial resistance to SDS was the strongest.The microbial diversity increased in lake-terrestrial ecotone with poor health status,and the community structure changed from single to complex.The community structure of the microorganisms in different health states of lake-terrestrial ecotone changed greatly,the nitrogen and carbon cycling functions were damaged,the sulfur cycling functions were enhanced,and there was a risk of pathogenic bacteria.The results of this study showed that the microbe in different health states had rate of SDS was the highest in healthy lake-terrestrial ecotone microorganisms.However,the resistance of microorganisms to SDS was strongest in lake-terrestrial ecotone with general health,and rhizosphere secretions of aquatic plants and benthic animals provided a good living environment for microorganisms.According to the demand of SDS treatment,lake-terrestrial ecotone with different health status can be constructed to cope with SDS pollution.