Microbial adaptation to bromobenzene in a chemostat

Abstract

Microorganisms capable of growth with bromobenzene as their sole source of carbon and energy were selected from a continuously growing community of microorganisms initially selected for growth at the expense of benzene as sole source of carbon and energy. The selection was by a gradient of increasing bromobenzene/decreasing benzene in the nutrient feed of the continuous culture. Generation times in the system were about 38h. These experiments selected two strains of Pseudomonas that used bromobenzene as sole carbon and energy source. These two strains appeared identical with two members of the original community which previously could not use bromobenzene. After the selection, the strains in either pure or mixed culture, were capable of growing at the expense of benzene, bromobenzene, and chlorobenzene, but not iodobenzene.