摘要
对甘草内生菌进行分离,并从中进行高产β-葡萄糖苷酶菌株的筛选,以利用微生物转化法将甘草黄酮糖苷水解成苷元,提高其抗氧化活性。结果从分离纯化出的47株甘草内生菌中筛选得到GF10和GF19两株高β-葡萄糖苷酶活性真菌,两株菌对甘草黄酮的转化实验结果表明:转化后黄酮的抗氧化活性均有显著增加,GF10、GF19对DPPH自由基的清除率分别达到71.67%、65.94%,比未经转化黄酮的清除率(20.68%)分别提高了246.57%、218.86%。对甘草黄酮主要成分的HPLC法检测结果表明,经微生物转化后,甘草苷与异甘草苷的质量浓度均有不同程度的降低,而甘草素和异甘草素的质量浓度则显著增加。其中GF19转化的处理,甘草素在4种黄酮物质中所占的比例最高,为29.18%,比转化前(10.38%)提高了181.12%;异甘草素比例最高的处理是GF10,为8.64%,比转化前(4.27%)高出102.34%。
Forty-seven endophytes were isolated from different parts （root, stem and leaf） of Glycyrrhiza inflate and potent 2 β-glucosidase-producing strains, designated as GF10 and GF19, were screened out of them. GF10 and GF19 were comparatively evaluated for their effectiveness in microbial transformation of flavonoid glucosides in Glycyrrhiza inflate into aglycones to obtain higher antioxidant activity. Both strains could increase the antioxidant activity of flavonoids, and the DPPH radical scavenging rates after fermentation with them were 71.67% and 65.94%, respectively, which were 246.57% and 218.86% higher than before fermentation （20.68%）. HPLC analysis showed that the concentrations of liquiritin and isoliquiritin decreased to different extents after microbial transformation, whereas the concentrations of liquiritigenin and isoliquiritigenin significantly increased. Liquiritigenin was the most abundant among four flavonoids with a percentage of 29.18% after GF19 transformation, which was 181.12% higher than the original level （10.38%）, while GF10 transformation made isoliquiritigenin the most dominant flavonoid and its percentage was increased from its original level （4.27%） to 8.64% by 102.34%.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2013年第1期194-198,共5页
Food Science
基金
新疆兵团青年科技创新资金专项(2010JC38)
新疆生产建设兵团塔里木盆地生物资源保护利用重点实验室开放课题(BR0804)
关键词
甘草
内生菌
Β-葡萄糖苷酶
甘草黄酮
转化
licorice： endophytes：β-glucosidase
licorice flavonoids： transformation
