海洋微藻脲酶活性测定方法的实验研究

为进一步了解海洋微藻对尿素的吸收和利用机制,揭示水体尿素浓度升高对近海浮游植物群落演替的潜在影响及对近海有害藻类水华(HABs)形成的促进作用,对海洋微藻脲酶活性的测定方法进行了研究.以典型赤潮藻东海原甲藻为实验材料,在Peers方法的基础上,探讨了失活处理时间、提取液pH值、酶促反应温度以及微藻生长阶段对脲酶活性的影响.结果表明,失活处理时间、提取液pH值、酶促反应温度以及微藻所处的生长阶段都对微藻的脲酶活性具有显著影响.海洋微藻脲酶活性的最佳测定条件为:100℃下失活处理时间 > 2min;提取液pH值7.9;反应温度应与微藻生长温度一致;指数生长初期的藻体具有较高的酶活,而平台期后酶活趋于稳定.

Experimental study of urease activity in marine microalgae

Assay optimization of urease activity in marine microalgae was studied in laboratory for further understanding the uptake and utilization mechanism of marine microalgac for urea and revealing effect of the increase of urea concentration for community succession of phytoplankton and its potential contribution to the formation of HABs in coastal waters.Based on Peers'method,effect of inactivation time,pH value ofthe extract,incubation temperature and growth phase of microalgae on urease activity in a representative HABs species Prorocentrum donghaiense isolated from East China Sea were discussed.The results showed that inactivation time,pH value of the extract,incubation temperature and growth phase of microalgae all significantly influenced urease activity in microalgae.The optimum conditions for detecting urease activity in microalgae were:inactivation time>2min under 100℃,pH of extract 7.9,incubation temperature consistent with the growth temperature of the microalgue,urease activity in microalgae higher during early exponential phase and stabilized after stationary phase.