Fig 2.

Pseudomonas putida strain Fu1 and Pseudomonas sp. strain A3 grown on 2-FA respond to a spatial gradient of furan molecules. (A). Strains Fu1 and A3 were grown on 5.0 mM 2-FA to provide inducing conditions. Cultures grown overnight with aeration were harvested and resuspended in chemotaxis buffer (CB) at an A₆₀₀ of 1.0. Low-melting-point agarose (2%, with Coomassie brilliant blue for contrast) contained CB (negative control), 10% Casamino Acids (CA; positive control), or 1.0 mM 2-FA. A characteristic white ring of cells that develops at the optimal attractant concentration diffusing from the agarose plug demonstrates chemotactic behavior and is indicated in these images by a white arrow. Images were documented after 10 min by photography using backlighting. Images shown are representative of assays conducted in triplicate. (B) P. putida strain Fu1 is attracted to furfuryl alcohol (FA) under the same assay conditions.