cis-benzeneglycol production using a mutant Pseudomonas strain

Abstract

The biotransformation of commodity aromatic chemicals into dihydroxy derivatives was studied. A strain isolated from the invironment, Pseudomonas JI104, used benzene, toluene, and other hydrocarbons as sole carbon and energy sources. We selected mutants unable to grow with benzene, and among these, screened for strains with deficient cis-benzenglycol dehydrogenase able to stably produce cis-benzeneglycol when another carbon source was co-metabolized.

We exained the possibility of cis-benzeneglycol production by growing the mutant strain in the presence of benzene vapor. Ethanol was the carbon and energy source most adapted to the cis-benzeneglycol production phase, and lactate or propanol could also be used. Glucose inhibited the production of the metabolite.

The growth rates were barely affected by the presence of benzene at a reduced partial pressure (less than 20% of saturation), showing that continuous culture is possible. In a batch process, 0.54g·1⁻¹ of a cell suspension produced 5.1 mmol·1⁻¹cis-benzeneglycol in 27 h, using ethanol as the energy source.