A BTEX mixture (benzene, toluene, ethylbenzene and o-, m- and p-xylene [1:1:1:1:1:1]) corresponding to 1000 mg/L was added directly to the flask and the enrichment flask was incubated with shaking at 180 rpm and 25 C. A BTEX mixture corresponding to 100 mg/L was added into
the enrichment culture to supplement BTEX reduction by vaporization every day.