Microbial transformation of geniposide in Gardenia jasminoides Ellis into genipin by Penicillium nigricans

A filamentous fungi strain, Penicillium nigricans, producing β-glucosidase was screened to transform geniposide in Chinese traditional medicine Gardenia jasminoides into genipin, a highly efficient anti-inflammatory, anti-angiogenesis compound used in treatment of liver fibrosis also. By modulating the fermentation process, including fermentation temperature, gardenia concentration, rotation speed and medium capacity, along with monitoring mycelial biomass, residual sugar concentration (RSC), ammoniacal nitrogen concentration (ANC), amount of substrate geniposide, and β-glycosidase activity the conversion rate of geniposide into genipin could reach 95%. Under the all-over feedback control system, genipin was isolated by macroporous resin and then purified by silica gel column with the final purity over 98%. Purified product was identified as genipin by high performance liquid chromatography (HPLC), ultraviolet (UV), nuclear magnetic resonance spectroscopy (NMR), infrared absorption spectrometry (IR) and mass spectrometry (MS).