中文摘要：

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/dm^3,酵母粉含量3 g/dm^3,NaCl含量10.45 g/dm^3,pH值9.5.

英文摘要：

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 16 S 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 2216 E medium containing 7. 5 g / dm^3 peptone,3 g / dm^3 yeast extract,10. 45 g / dm^3 NaCl,and pH 9. 5.