红景天有效成分微生物发酵高值化转化

High value conversion of effective components in Rhodiola by microbial fermentation

通过分离筛选出能将L-酪氨酸转化成酪醇的菌株,并将其应用于中药红景天中,以提高其中酪醇(tyrosol,TYR)和红景天苷(salidroside,SAL)含量及其抗氧化活性。采用含有酪氨酸的平板通过pH变化筛选出产酪氨酸脱羧酶的菌株,并通过高效液相色谱(HPLC)和液质联用(liquid chromatograph-mass spectromete,LC-MS)确定了9株能够转化成酪醇的菌株。然后用这些菌株分别以红景天为底物进行发酵炮制,发酵后红景天中酪醇含量由原发酵前的0. 23 g/L增加为0. 78g/L,提高了235%,红景天苷含量由发酵前的0. 21 g/L增加到0. 43g/L,提高了109. 9%。发酵液的总还原力是提取液的1. 7倍,DPPH·清除能力由发酵前的35. 45%增加到61. 01%。

The strains that are capable to transform L -tyrosine to tyrosol were applied to a Chinese medicine Rhodiola to increase the contents of its active ingredients, such as tyrosol and salidroside, and to enhance its antioxidant activity. Tyrosine decarboxylase producing strains were screened using a tyrosine-containing plate through pH changes, and nine strains that could produce tyrosol were determined by high performance liquid chromatography (HPLC) and liquid chromatograph-mass spectrometry (LC-MS). Rhodiola was fermented by these strains, and the yield of tyrosol after fermentation was 0.78g/L, which increased by 235%. The content of salidroside increased by 109% and reached 0.43g/L. The total reducing power after fermentation was 1.7 times higher than that of the extract, and the DPPH scavenging capacity increased from 35.45% to 61.01%. This study provides a new idea for developing and applying Rhodiola in the future.