Performance of Luffa cylindrica as an immobilization matrix for the biotransformation of cholesterol by Mycobacterium species

The microbial cleavage of the side chain of cholesterol is a slow process due to the low solubility of the substrate in aqueous media (< 1 mu M). Cell immobilization has been shown to be an efficient technology for enhancing the yield of cholesterol biotransformation. In these experiments, living cells of Mycobacterium sp. DSM 2966 and Mycobacterium sp. DSM 2967 were immobilized by passive adsorption on different types of solid carriers. As compared to the control and other solid supports, Luffa cylindrica resulted in a 3 4-fold increase of the specific side chain cleavage activity after 7 days of incubation. Luffa cylindrica had no significant negative influence on cell growth. Furthermore, it is a natural, inexpensive, non-toxic and mechanically strong material and therefore suitable for follow-up experiments.