State Key Laboratory of Marine Environmental Science and Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, School of Life Sciences, Xiamen University, Xiamen 361102, China.
Biology Department, College of Life Science, Shantou University, Shantou 515063, China.
J Hazard Mater. 2018 Jan 5;341:138-149. doi: 10.1016/j.jhazmat.2017.06.046. Epub 2017 Jun 23.
To find the potential algicidal microorganisms and apply them to prevent and terminate harmful algal blooms (HABs), we isolated an actinomycete U3 from Mangrove, which had a potent algicidal effect on the harmful alga Heterosigma akashiwo. It could completely lyse the algal cells by producing active compounds, which were highly sensitive to high temperature and strong alkaline, but resistant to acid. One μg/mL of crude extract of the fermentation supernatant could kill 70% of H. akashiwo cells in 3 d. Unlike most of the other known algicidal Streptomyces, U3 showed strong ability of proliferation with the algal inclusion as the nutrient source. The washed mycelial pellets also gradually exhibited significant algicidal effect during the visible growth in the algal culture. It suggests that U3 could efficiently absorb nutrients from algal culture to support its growth and produce algicidal compounds that might cause the autophagy of algal cells. Therefore, applying U3, as a long-term and environmentally friendly bio-agent to control the harmful blooms of H. akashiwo, would be effective and promising. And the decrease of bioavailable DOM and increase of bio-refractory DOM during the algicidal process of U3 provided new insights into the ecological influence of algicial microorganisms on marine ecosystem.
为了寻找潜在的杀藻微生物，并将其应用于防治有害藻华（HABs），我们从红树林中分离出一株放线菌 U3，它对有害藻类赤潮异弯藻具有很强的杀藻作用。它可以通过产生活性化合物完全裂解藻细胞，这些化合物对高温和强碱性非常敏感，但对酸性有抗性。发酵上清液的粗提物 1μg/mL 在 3 天内可杀死 70%的赤潮异弯藻细胞。与大多数已知的杀藻链霉菌不同，U3 以藻类包含物作为营养源显示出很强的增殖能力。在藻类培养中可见生长过程中，洗涤后的菌丝体球也逐渐表现出显著的杀藻作用。这表明 U3 可以从藻类培养物中有效地吸收营养物质来支持其生长，并产生可能导致藻细胞自噬的杀藻化合物。因此，将 U3 作为一种长期的、环保的生物制剂来控制赤潮异弯藻的有害藻华将是有效和有前途的。并且 U3 的杀藻过程中生物可利用 DOM 的减少和生物难降解 DOM 的增加为杀藻微生物对海洋生态系统的生态影响提供了新的见解。
