Lakes in arid northwestern China are valuable freshwater resources that drive socioeconomic development. Microbial communities played an important role in the element biogeochemical cycle. Hence, it is important to understand the relationship of bacterial community composition and functional genes (i.g. metal resistance genes, MRGs) with the environmental pollutants.
Dr. Wenjuan Song from Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences chose the classical Bosten Lake and Ebi Lake as the studied lakes from arid region. The main aims of this study were: (1) to quantify the occurrence and accumulation of heavy metals in water, sediment and biofilm; (2) to identify the composition of microbial communities in water, sediment and biofilm; (3) to compare the distributions of MRGs in water, sediment and biofilm; (4) to investigate the correlations between heavy metals, bacterial community composition and MRGs.
Research results show that the mercury resistance gene subtype merP had the greatest average abundance (4.61×10-3 copies per 16S rRNA) among all the samples, followed by merA and merC. The high abundance of merA in the pelagic zone rather than in benthic sediment suggests that the pelagic microbial community was important in mercury reduction. Proteobacteria were the main phylum found in the microbial communities in all samples. However, microbial communities in most of the water, sediment and biofilm samples had different compositions, indicating that the habitat niche plays an important role in shaping the bacterial communities in lakes. The microbial community, rather than the heavy metals, was the main driver of MRG distribution. The abundances of some bacterial genera involved in the decomposition of organic matter and the terrestrial nitrogen cycle were negatively correlated with heavy metals. This result suggests that metal pollution can adversely affect the biogeochemical processes that occur in lakes.
This study provide a comprehensive understanding of the bacterial communities and MRGs in different environments. The manuscript entitled "bacterial community rather than metals shaping metal resistance genes in water, sediment and biofilm in lakes from arid northwestern China" was published in Environmental Pollution.
Article link: https://www.sciencedirect.com/science/article/pii/S0269749119316859
Contact: LIU Jie, Xinjiang Institute of Ecology and Geography