Isolation and characterization of halophilic archaea able to grow in aromatic compounds

Benzoic acid and its hydroxylated derivatives are naturally occurring compounds that are also released into the environment in large amounts through industrial wastewater, automobile exhaust and tobacco smoke. Even though these compounds are readily degraded under mild environmental conditions, little is known about their metabolism in extreme environments such as hypersaline lakes. Five hypersaline sites, the Uyuni Salar (Bolivia), solar salterns in Cahuil (Chile), solar salterns in Cabo Rojo (Puerto Rico), sabkhas (Saudi Arabia) and the Dead Sea (Jordan), were tested for the presence of halophilic archaea able to metabolize aromatic compounds:. Forty-four new halophilic archaea able to grow in p-hydroxybenzoic acid (0.4 mM) as the sole carbon and energy source were isolated. On the basis of the metabolic and genetic diversity of these isolates, and their occurrence in all tested sites, it is suggested the ability to degrade p-hydroxybenzoic acid is a widespread feature among the Halobacteriaceae.