| 摘要: |
| 根据13株分离自药用植物地锦草（Euphorbia humifusa）的内生放线菌的酶活性以及抗菌、抗氧化等重要特征来首次探讨地锦草内生放线菌的生物活性，以期为开发新的活性物质提供参考依据。通过观察菌落周围是否有透明圈对分泌的胞外淀粉酶、脂肪酶、纤维素酶等常见酶进行活性测定；使用滤纸扩散法检测菌株抗菌活性；利用PCR特异性扩增检测菌株的PKS-Ⅰ, PKS-Ⅱ, NRPS基因；对菌株发酵液乙酸乙酯粗提物进行抑菌、抗氧化活性检测，并对高活性菌株进行形态观察及16S rDNA系统进化分析鉴定。结果表明：13株菌中至少12株菌具有一种酶活性，其中2株可同时产生以上3种酶。4株具有稳定且较强的抑菌能力，13株菌生物合成基因PCR筛查结果均为阴性。1株菌对DPPH自由基有较强清除作用（清除率≥50%），2株菌对·OH自由基有较强清除作用（清除率≥50%）。其中L57的活性物质粗提物具有广谱抗菌活性，对鲍曼不动杆菌的抑菌圈直径达22.62 mm，并对DPPH自由基具有较强清除率，经形态观察及16S rDNA序列分析初步确定L57归属为噬油微杆菌（Microbacterium oleivorans）。研究证明地锦草内生放线菌可作为探寻新型活性物质的良好资源。 |
| 关键词: 地锦草 内生放线菌 抗氧化 PCR筛查 抗菌 |
| DOI：10.14188/j.ajsh.2019.01.009 |
| 分类号:Q93，Q939.13+2 |
| 基金项目:新疆大学博士科研启动基金项目201604061076新疆大学博士科研启动基金项目(201604061076) |
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| Bioactivity and identification of endophytic actinomycete from Euphorbia humifusa |
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Ayati KAIDIYA,Memettursun RAZIYA,Anvar NUSRATGUL,Yunus ZULFIYA
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College of Life Sciences and Technology ， Xinjiang University，Urumqi 830000, Xinjiang, China
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| Abstract: |
| In 13 endophytic actinomycete strains isolated from Euphorbia humifusa, the feature of excreting enzyme, antimicrobial activity and antioxidant activity were explored in order to provide reference for the development of new active substances. The activities of enzymes such as amylase, lipase and cellulase were determined by observing the transparent circle. The antimicrobial activity was measured with the filter paper method, the secondary metabolite genes of PKSI/PKSⅡ and NRPS were detected by PCR amplification, the antimicrobial activity and antioxidant activity of the crude fermentation extract of highly active strains were also detected. The identification was also based on morphological characteristics and the 16S rDNA gene sequence similarity analysis. Results indicated that: in total 13 endophytic actinomycete strains 12 strains could produce at least one enzyme, 2 strains could simultaneously produce amylase, cellulase and lipase; 4 strains showed stable and high activity against pathogenic bacteria; 1 strain had a better DPPH radical scavenging activity (clearance rate≥50%); 2 strains showed strong ·OH free radical scavenging capacity (clearance rate≥50%); the results of PCR screening of the biosynthetic genes of 13 strains were all negative. Furthermore, the strain L57 which showed wide antimicrobial properties and strong DPPH radical scavenging activity was defined as Microbacterium oleivorans according to the characteristics of morphology and 16s rDNA sequence analysis. The maximum suppression width of the L57 reached 22.62 mm on Acinetobacter baumannii plates. Our results demonstrated that, the endophytic actinomycete from medical plant Euphorbia humifusa are good sources for discover the new active substances. |
| Key words: Euphorbia humifusa endophytic actinomycete antioxidation PCR screening antibiosis |
