Studies on microbiological degradation of tobacco tar.

A bacterium, strain MR4, was isolated from tobacco tar-contaminated soil and identified as Klebsiella oxytoca based on morphology, physiological and biochemical characteristics and phylogenetic analysis of 16S rDNA sequence. The organism grew optimally at 34 degrees C and pH 7.0 to 7.5. During growth on tobacco tar the isolate produced acid materials, which caused the drop of pH in the cultures. GC/MS analysis indicated that the isolate had the ability to degrade phenolic compounds, heterocyclic compounds, especially nicotine in tobacco tar. The degradation rate of strain MR4 was 75.56% for nicotine, 35.84% to 58.16% for hydroxybenzenes and the other aromatic compounds, 29.15% to 65.56% for heterocyclics, and 35.17% to 82.59% for hydrocarbons.