Study on Conversion of Conjugated Anthraquinone in Radix et Rhizoma Rhei by Yeast Strain / 世界科学技术-中医药现代化

ABSTRACT

A yeast strain KM12 , which can convert conjugated anthraquinone of rhub arb to free anthraquinone , was screened. And it is identified as Kluyveromyces marxianus by 26S rDNA. The percentage of free an-thraquinone in total anthraquinone of rhub arb as an indicator was used to investigate the effect of culture medium component and fermentation processing conditions, such as seed age, fermentation time and liquid volume on con-version of conjugated anthraquinone by KM12. The optimal fermentation medium was determined by orthogonal test L9(43) and the composition (%) is yeast extract 1, glucose 2, and rhubarb 2. The 5% (V/V) of the seed culture inoculated 36-48 h was inoculumed to fermentation medium in shake flask to ferment at 30℃, 200 r?min-1 for 4 days. TLC analysis showed most of conjugated anthraquinone decomposed or converted into free anthraquinone in fermented rhub arb . It was concluded that the side effect of severe diarrhea caused by Chinese medicine rhub arb can be alleviated through fermentation processing by KM12 strain .