摘要
本实验通过形态学鉴定和PCR扩增r DNA-ITS序列分析,确定两株长白内生真菌Ra-R-32、ZPRa-S-2的种属,采用正交设计优化其DPPH抗氧化发酵条件,并通过测定DPPH·清除能力、·OH-清除能力、Fe2+螯合能力、O-·2清除能力及亚硝酸盐清除能力等方法对其抗氧化活性综合评价。实验显示,Ra-R-32和ZPRa-S-2分别隶属于Hypocrea longipilosa和Aspergillus sydowii;Ra-R-32培养的最佳条件为:葡萄糖35 g/L,蛋白胨3 g/L,p H8,35℃,装液量100mL/250mL;ZPRa-S-2培养的最佳条件为:蔗糖35 g/L,牛肉膏3 g/L,p H 6,30℃,装液量150mL/250mL。最佳发酵时间都为10 d。它们的DPPH·清除能力、·OH-清除能力、O-·2清除能力较强,其中,Ra-R-32的EC50值分别为4.72、7.50、1.60 mg/m L;ZPRa-S-2的EC50值分别为2.88、8.99、4.12 mg/m L。结果表明优化条件下二株菌均具有良好的抗氧化能力。
Two endophytlc fungi, Ra-R-32 and ZPRa-S-2, from Rhodiola angusta were isolated and identified. Their fermentation conditions and antioxidant activity were optimized and evaluated, respectively. Fungal identification methods were based on morphological observation and their ITS ribosomal DNA sequences. Orthoganal test was applied to optimize the fermentation conditions based on scavenging DPPH · activity. In addition, the antioxidant activities were subjected to DPPH radical scavenging, hydroxyl radical scavenging, Fe^2 ＋ chelating, superoxide radical scavenging and ni- tilde clearing assays. The results showed that Ra-R-32 and ZPRa-S-2 belonged to Hypocrea longipilosa and Aspergillus sydowii, respectively. The optimal fermentation conditions for Ra-R-32 were as follows： glucose 35 g/L, peptone 3 g/L, initial pH at 8.0, the loading volume was 100 mL in 250 mL flask, and culture temperature was 35 ℃. The optimal fermentation conditions for ZPRa-S-2 were as follows ： sucrose 35 g/L, beef extract 3 g/L,initial pH at 6.0, the loading volume was 150 mL in 250 mL flask,and culture temperature was 30 ℃ ,and the optimal fermentation time for both fungi were 10 d. Both fungi exhibited excellent scavenging capacities against DPPH, hydroxyl radical and superoxide anion. The ECs0 values of Ra-R-32 were 4.72,7.50 and 1.60 mg/mL;and the EC50 values of ZPRa-S-2 were 2.88,8.99 and 4.12 mg/mL, respectively. The results showed that two endophytie fungi from R. angusta have remarkable antioxidant capacity.
出处
《天然产物研究与开发》
CAS
CSCD
北大核心
2015年第4期667-673,654,共8页
Natural Product Research and Development
基金
国家自然科学基金(31270383)
高等学校博士学科点专项科研基金(20121401120001)
山西省自然科学基金(2014011029-1)
关键词
长白红景天
内生真菌
抗氧化
条件优化
Rhodiola angusta
endophytie fungi
antioxidant
fermentation optimization
