Adaptive Evolution of Sphingobium hydrophobicum C1^T in Electronic Waste Contaminated River Sediment

Journal Article · 02 October 2019 · Frontiers in Microbiology

DOI: https://doi.org/10.3389/fmicb.2019.02263 · OSTI ID:1580867

Song, Da ^[1]; Chen, Xingjuan ^[2]; Xu, Meiying ^[2]; Hai, Rong ^[3]; Zhou, Aifen ^[4]; Tian, Renmao ^[4]; Van Nostrand, Joy D. ^[4]; Kempher, Megan L. ^[4]; Guo, Jun ^[2]; Sun, Guoping ^[2]; Zhou, Jizhong ^[4]

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1. South China Univ. of Technology (SCUT), Guangzhou (China); Guangdong Academy of Sciences, Guangzhou (China). State Key Lab. of Applied Microbiology Southern China, Guangdong Provincial Key Lab. of Microbial Culture Collection and Application, Guangdong Inst. of Microbiology
2. Guangdong Academy of Sciences, Guangzhou (China). State Key Lab. of Applied Microbiology Southern China, Guangdong Provincial Key Lab. of Microbial Culture Collection and Application, Guangdong Inst. of Microbiology
3. Univ. of California, Riverside, CA (United States)
4. Univ. of Oklahoma, Norman, OK (United States)

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 C1^T, 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 C1^T 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 C1^T and other Sphingobium strains, numerous C1^T-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 C1^T. Moreover, presence of type IV secretion systems may allow strain C1^T 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.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1580867
• Journal Information: Frontiers in Microbiology, Journal Name: Frontiers in Microbiology Vol. 10; ISSN 1664-302X
• Publisher: Frontiers Research FoundationCopyright Statement
• Country of Publication: United States
• Language: English