银杏花粉生物转化菌株的筛选及发酵条件优化

Strain Screening and Optimization of Fermentation Conditions for Ginkgo Pollen Biotransformation

银杏花粉富含黄酮类化合物,且主要是黄酮苷。为了发酵银杏花粉并高效转化银杏花粉黄酮苷,本研究从保存的22株乳酸菌出发对生物转化菌株进行筛选,并进行生理生化和分子生物学鉴定;同时采用单因素试验从发酵温度、接种量、发酵时间、银杏花粉料液比4个参数对发酵条件进行优化。结果筛选出一株能单一利用银杏花粉生长并高效转化银杏花粉黄酮苷的菌株B_2,经鉴定为恶味乳杆菌。单因素试验结果表明,当发酵温度37℃、接种量2%(v/v)、发酵时间72 h、银杏花粉培养基的料液比1∶4(w/v)时,转化产物中的山奈酚含量最高。本研究结果为银杏花粉的深加工及功效成分研究奠定了理论基础。

Previous studies had found that Ginkgo pollen was rich in flavonoids,mainly in the form of flavonoid glycosides. In order to ferment the Ginkgo pollen and efficiently transform the flavonoid glycosides in it, the biotransformation strains were screened from 22 strains of lactic acid bacteria stored in the laboratory and identified by physiological,biochemical and molecular biology analysis. Then,the biotransformation conditions of Ginkgo biloba flavonoids were optimized from four parameters of fermentation temperature,inoculation amount,fermentation time and solid-liquid ratio of Ginkgo pollen by a single factor test. Finally,a strain was successfully screened and identified as Lacbacillus perolens B2,which could grow on Ginkgo pollen. The single factor test showed that the content of kaempferol was highest production in the conversion production under the optimized fermentation conditions of fermentation temperature was 37℃,the inoculation amount was 2%（ v/v）,the fermentation time was 72 h,and the solid-liquid ratio of Ginkgo pollen was 1 ∶ 4（ w/v）. This study laid a foundation for the deep processing and active components research of Ginkgo pollen.