干旱区生态环境知识资源中心

We performed a series of experiments with Geobacillus stearothermophilus, a thermophile isolated from oil-contaminated soil in the Kuwaiti desert. The organism has a good potential for the transformation of a broad spectrum of organic molecules such as steroids, amino acids, and aromatic hydrocarbons. In the present study, we tested its potential for the transformation of a bile component, chenodeoxycholic acid (CDCA). Five transformed products, namely, cholic acid, methylcholate, methylchenodeoxycholate, 3 alpha-hydroxy-7-oxo-5 beta-cholanic acid, and 7 alpha-hydroxy-3-oxo-5 beta-cholanic acid, were the major transformation products catalyzed by G. stearothermophilus. Under aerobic conditions, no evidence of side chain degradation, ring cleavage, or dehydrogenation was found among the metabolites of CDCA. CDCA transformation by a thermophile is reported for the first time.