A new technique for promoting cyclic utilization of cyclodextrins in biotransformation

Cyclodextrins (CDs) can improve the productivity of steroid biotransformation by enhancing substrate solubility. CDs can be recycled by grafting them with appropriate carriers. Loofah fiber is an excellent grafting material for CDs, and can be applied to the biotransformation and recycling of beta-cyclodextrin (beta-CD). In this work, a technique for recycling beta-CD in cortisone acetate (CA) biotransformation by Arthrobacter simplex CPCC 140451 was studied. Loofah fiber-grafted beta-CD (LF-beta-CD) was prepared using epichlorohydrin, which is a cross-linking agent. The grafting yield of beta-CD was 74.8 mg g(-1) dried fibers. LF-beta-CD could increase the solubility of CA and enhance biotransformation. The initial conversion rate of CA was 1.5-fold higher than that of the blank group. LF-beta-CD was also used in biocatalytic reactions for eight cycles, and it maintained the conversion ratio of CA at approximately 90%. Given the above positive results, LF-beta-CD can be utilized in biotechnological recycling applications. This method can also be applied to CD derivatives and hydrophobic compounds.