Chromate reduction is expedited by bacteria engineered to produce the compatible solute trehalose

Document Type


Publication Date


Publication Title

Biotechnology Letters


Bioaugmentation, Bioremediation, Chromate, Chromium, Trehalose


The toxicity and solubility of chromium(VI) can be decreased by certain microbes that reduce chromium(VI) to chromium(III). However, these bacteria do not escape unscathed from this process. Chromium(VI) reduction damages the essential macromolecules of living systems. Trehalose protects organisms from chemical stress but has not been tested in the context of bioremediation. We engineered bacteria to produce trehalose and found that they then reduced 1 mM chromium(VI) to chromium(III), whereas wild-type cells were only able to reduce half that amount. Thus, by providing bacteria with a biochemical defense against the side-effects of chromate reduction may be a new approach to cleaning up sites that are contaminated with high levels of chromate.


The authors wish to thank Alfred Goldberg and Olga Kandror for bacterial strains, Ryan Shultzaberger for the pBAD18 construct, and Danielle Dube for comments on the manuscript. This work was supported by a Bowdoin College Faculty Resources Award, by the National Institutes of Health (Grant P20 RR-016463 from the INBRE Program of the National Center for Research Resources), by an award to Bowdoin College by the Howard Hughes Medical Institute under the Undergraduate Science Education Program, and by startup funds from the University of Southern Maine.