Adaptive Evolution of Sphingobium hydrophobicum C1T in Electronic Waste Contaminated River Sediment

Frontiers in Microbiology

Rong Hai¹  Renmao Tian²  Megan L. Kempher²  Aifen Zhou²  Jizhong Zhou²  Joy D. Van Nostrand²  Jun Guo⁴  Guoping Sun⁴  Xingjuan Chen⁴  Meiying Xu⁴  Da Song⁴ 

[1] Department of Plant Pathology and Microbiology, University of California, Riverside, Riverside, CA, United States;Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, United States;School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China;State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China;

关键词: Sphingobium;    electronic waste (e-waste);    xenobiotic degradation;    heavy metal resistance;    comparative genomics;    genome plasticity;   

DOI  :  10.3389/fmicb.2019.02263

来源: DOAJ

【 摘 要 】

Electronic waste (e-waste) has caused a severe worldwide pollution problem. Despite increasing isolation of degradative microorganisms from e-waste contaminated environments, the mechanisms underlying their adaptive evolution in such habitats remain unclear. Sphingomonads generally have xenobiotic-degrading ability and may play important roles in bioremediation. Sphingobium hydrophobicum C1T, characterized with superior cell surface hydrophobicity, was recently isolated from e-waste contaminated river sediment. To dissect the mechanisms driving its adaptive evolution, we evaluated its stress resistance, sequenced its genome and performed comparative genomic analysis with 19 other Sphingobium strains. Strain C1T can feed on several kinds of e-waste-derived xenobiotics, exhibits a great resistance to heavy metals and possesses a high colonization ability. It harbors abundant genes involved in environmental adaptation, some of which are intrinsic prior to experiencing e-waste contamination. The extensive genomic variations between strain C1T and other Sphingobium strains, numerous C1T-unique genes, massive mobile elements and frequent genome rearrangements reflect a high genome plasticity. Positive selection, gene duplication, and especially horizontal gene transfer drive the adaptive evolution of strain C1T. Moreover, presence of type IV secretion systems may allow strain C1T to be a source of beneficial genes for surrounding microorganisms. This study provides new insights into the adaptive evolution of sphingomonads, and potentially guides bioremediation strategies.

【 授权许可】

Unknown