溶藻细菌A3的溶藻特性

Characteristics of Algicidal Activity of Bacterial Strain A3

中文关键词: 溶藻菌A3  微藻调控  溶藻选择性

英文关键词: Algicidal bacteria A3  Microalgae control  Algicidal specificity

中文摘要:

      本研究以锥状斯氏藻(Scrippsiella trochoidea)、蛋白核小球藻(Chlorella pyrenoidosa)、四尾栅藻(Scenedesmus quadricauda)、条纹小环藻(Cyclotella striata)作为实验藻种，将浓度为107 CFU/ml的菌株A3分别加入到4种微藻的单种藻液、2种藻混合藻液、3种藻混合藻液中，每48 h观察藻细胞形态并统计藻细胞数量，实验周期为10 d，以探究菌株A3对4种微藻的溶藻效果。结果显示，在单种藻实验中，加菌组锥状斯氏藻细胞于第1天失去运动活性，细胞拉长变形，第5天细胞壁破裂溶解，第10天细胞密度为7.07×102 cells/ml，显著低于对照组的2.90×104 cells/ml (P<0.05)；实验期间，加菌组蛋白核小球藻细胞形态保持完整，第10天藻细胞密度为2.58×107 cells/ml，显著高于对照组的2.09×107 cells/ml (P<0.05)；加菌组四尾栅藻细胞形态保持完整，与对照组藻细胞密度无显著差异(P>0.05)；加菌组条纹小环藻细胞于第8天溶解，第10天对照组与加菌组藻细胞密度分别为4.38×105 cells/ml、1.78×105 cells/ml，加菌组藻细胞密度显著低于对照组(P<0.05)。混合藻实验中，菌株A3对各种微藻的溶藻效果与单种藻实验结果类似，菌株A3对锥状斯氏藻生长具有显著的溶藻作用，对蛋白核小球藻与四尾栅藻无溶藻作用，对条纹小环藻生长具有较弱的溶藻作用。研究表明，菌株A3具有溶藻选择性，对锥状斯氏藻具有显著的溶藻作用，而对其他3种藻无溶藻作用或溶藻作用相对较弱。

英文摘要:

      In this study we performed a series of experiments in order to find an effective control of dinoflagellate in microalgal community of the water environment. Scrippsiella trochoidea, Cyclotella striata, Chlorella pyrenoidosa, and Scenedesmus quadricauda were used as representative microalgal species in this study. Strain A3 was added into either monoculture or mix-culture systems of the four microalgaes at a concentration of 107 CFU/ml, and the morphology and cell density of the microalgae were analyzed every 48 hours for 10 days. Treated with A3, S. trochoidea in the monoculture system lost the motion activity on Day 1, then they inflated and finally lysed on Day 5. The cell density of S. trochoidea was 7.07×102 cells/ml on Day 10, which was significantly lower than that of the control group (P<0.05). Morphology of C. pyrenoidosa was not affected by Strain A3. The cell density of C. pyrenoidosa was 2.58×107 cells/ml on Day 10, and it was higher than that of the control group (P<0.05). Morphology of S. quadricauda was also unaffected by Strain A3. There was no significant difference in the cell density of S. quadricauda between the experimental group and the control group (P>0.05). C. striata lysed due to the effects of A3 on Day 8, and the cell density of C. striata in the control group and the experimental group were 4.38×105 cells/ml and 1.78×105 cells/ml, respectively. The lytic effect of Strain A3 on four microalgal species in the mix-culture systems was similar to that in the monoculture systems. These results suggested that Strain A3 might have strong lytic effect on S. trochoidea in the mix-culture systems. However, Strain A3 did not inhibit the growth of S. quadricauda and C. pyrenoidosa, and had weaker lytic effect on C. striata. Therefore, the algicidal activity of Strain A3 was highly specific to S. trochoidea, and hence could be used to develop probiotics against dinoflagellate blooms in aquaculture ponds.