Author(s) Cheng, L.; Min, D.; Liu, D.F.; Li, W.W.; Yu, H.Q.
Journal Environ Sci Technol
Date Published 2019 Dec 17

Although arsenic at a high concentration imposes strong selective pressure on microbes, various microbes have been found to grow in As-rich environments. So far, little is known about how microbes can sense and move toward arsenate in the environment, and the underlying molecular mechanisms have not been revealed. Here, we report the chemotaxis response toward arsenate (As(V)) by CN-32, a model dissimilatory metal-reducing bacterium (DMRB), and elucidate the mechanisms. We find that CN-32 exhibits a chemotactic behavior toward As(V) and diverse electron acceptors. To sense As(V), CN-32 requires functional arsenate respiratory reductase but does not depend on its metal-reducing-like respiratory pathway. We observe that such a sense is governed by an energy taxis mechanism and mediated by several methyl-accepting chemotaxis proteins (MCPs), rather than a specific MCP. Moreover, we reveal that the chemotactic signal transduction pathway is conserved in , and histidine kinase and flagella-mediated motility are essential for taxis toward As(V). This work reverses the conventional view about arsenic as a chemotactic inhibitor to microbes by revealing the positive chemotaxis of to As(V).

DOI 10.1021/acs.est.9b05890
ISSN 1520-5851
Citation Environ Sci Technol. 2019;53(24):1460414611.

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