A Pseudomonas thrives in high concentrations of toluene

TLDR: A variant strain of Pseudomonas putida is discovered which is capable of growing in media culture containing more than 50% toluene or high concentrations of cyclohexane, xylene, styrene and heptanol, and it is shown that the relative toxicities of different solvents are determined by their polarities.

Abstract: TOLUENE, like many organic sovents, is highly biotoxic and kills most microorganisms at low concentrations (0.1% v/v). It is often used therefore to sterilize microbial cultures and lyse bacterial cells in the assay of bacterial enzymes1–3. The physiological basis of such solvent toxicity, however, remains poorly characterized. Although some microorganisms, including Pseudomonas4–6 , Achromobacter4 and Nocardia7 , can assimilate toluene, their toler-ance for the solvent is less than 0.3% (v/v). We report here the discovery of a variant strain of Pseudomonas putida which is capable of growing in media culture containing more than 50% (v/v) toluene or high concentrations of cyclohexane, xylene, styrene and heptanol. By studying this unusually tolerant strain we show that the relative toxicities of different solvents are determined by their polarities.