| 摘要: |
| 为了从海绵共附生微生物中寻找天然高效抗污损活性物质，本文针对前期研究获取的4株具有显著抗硅藻附着的活性菌株进行活性验证和比较，选出其中最优菌株进行菌种鉴定及发酵条件优化.比较了活性菌株对小新月菱形藻（Nitzschia closterium）、咖啡双眉藻（Amphora coffeaeformis）、碎片菱形藻（Nitzschia frustulum）附着的抑制活性，确定菌株UST050418-715为最优菌株；通过16S rDNA的测序分析，结合平板的菌落形态和扫描电镜下菌体特征，鉴定活性菌株UST050418-715为短小芽孢杆菌（Bacillus pumilus）.为优化该菌株的培养条件，选择了酵母粉、蛋白胨、NaCl、pH值进行四因素三水平的正交实验，对菌株培养条件进行优化.发现选择的4个因素对应的菌株发酵产物对硅藻附着的抑制活性大小不同，影响显著性顺序是酵母粉>蛋白胨>NaCl>pH值，综合菌株发酵产物活性、粗提物产量和菌株生长情况进行分析，确定菌株UST050418-715基于海洋2216E培养基的最佳发酵条件为：蛋白胨含量7.5 g/dm3，酵母粉含量3 g/dm3，NaCl含量10.45 g/dm3，pH值9.5. |
| 关键词: 海洋生物学 海绵共附生微生物 抗硅藻附着 菌株鉴定 发酵条件优化 正交试验 |
| DOI： |
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| 基金项目:国家自然科学基金资助项目(41306131，41106113，41271521)；教育部科学技术研究重点项目资助项目(211065)；江苏省自然科学基金资助项目(BK2012267，BK20130440)；江苏省教育厅高校自然科学基金资助项目(13KJB180029，11KJB170011) |
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| Identification and culture conditions optimization for an active sponge-associated bacterium against diatom attachment |
| LIU Shuyu,YU Siyu,XIA Yiteng,JIN Cuili,ZHANG Likui,ZHOU Xiaojian |
| (College of Environmental Science & Engineering， Yangzhou University， Yangzhou 225127， China;Marine Science & Technology Institute， Yangzhou University， Yangzhou 225127， China) |
| Abstract: |
| To search for natural and efficient anti-fouling active substances， 4 sponge-associated microorganisms， which were preliminarily found with strong activities of restraining diatom attachment， were selected to verify and compare their activities. The most active bacterial strain of UST050418-715 was selected based on the activities against the settlement of 3 tested diatoms， including Nitzschia closterium， Amphora coffeaeformis， and Nitzschia frustulum. And the strain UST050418-715 was identified as Bacillus pumilus based on the 16S rDNA sequence analysis， cell morphology and colony characteristics. To optimize the cultivation conditions of strain UST050418-715， orthogonal tests were carried out with 4 factors （yeast extract concentration， peptone concentration， NaCl concentration and pH） and 3 levels. The 4 factors all affected the anti-settlement activities of fermentation products， and interferential efficiencies of which are yeast concentration > peptone concentration > NaCl concentration > pH.Combined the results of orthogonal tests with crude exact yields and growth of the strain， the optimum culture conditions of UST050418-715 were concluded as marine 2216E medium containing 7.5 g/dm3 peptone， 3 g/dm3 yeast extract， 10.45 g/dm3 NaCl， and pH 9.5. |
| Key words: marine biology sponge-associated microbes restraining diatom settlement strain identification optimization of culture conditions orthogonal test |
