亚麻刺盘孢表面磁纳米修饰及其羟化去氢表雄酮

Magnetic nanoparticles modification of Colletotrichum lini and its application in bio-hydroxylation of dehydroepiandrosterone

以阳离子聚电解质聚烯丙基胺盐酸盐(PAAH)对共沉淀法制备的Fe_3O_4磁性纳米颗粒进行包裹,再以此对亚麻刺盘孢Colletotrichum lini ST-1进行表面修饰,制备具有磁性的菌体复合物。通过SEM、XRD、VSM和zeta电位分析表明,PAAH修饰的Fe_3O_4能够稳定均一地结合在C.lini ST-1菌体表面,形成的磁性复合物具有超顺磁性,可利用外加磁场对菌体进行回收。本研究利用该磁性复合物对去氢表雄酮(DHEA)进行生物羟化,制备三羟基雄甾烯酮(7α,15α-di OH-DHEA),通过回收菌体完成了4个批次的转化,产物7α,15α-di OH-DHEA的浓度为10.83g/L,约为游离菌体转化效果的3倍。

The cationic polyelectrolyte modified magnetic nanoparticles were prepared through surface modification of Fe3O4nanoparticles that were prepared by co-precipitation method with poly(allylamine hydrochloride)(PAAH).The fungi of Colletotrichum lini ST-1was then coated with the modified Fe3O4nanoparticles to form magnetic composites.The magnetic composites were characterized by SEM,XRD,VSM,and zeta potential.The results demonstrated that the modified Fe3O4nanoparticles adsorbed onto C.lini ST-1cell surface stably and uniformly by electrostatic adsorption.The magnetic composites exhibited superparamagnetic properties,which could be utilized for strain recovery.During the biotransformation of dehydroepiandrosterone(DHEA)to3β,7α,15α-trihydroxy-5-androsten-17-one(7α,15α-diOH-DHEA),the magnetic composites could be recovered by the application of external magnetic field for4batches.The concentration of7α,15α-diOH-DHEA was10.83g/L,which was about3times higher than that of the free cells.