微小原甲藻的生长及其对锌限制的响应

研究了低中高3种Zn2+浓度下，赤潮藻微小原甲藻的生长和生理响应．结果表明，低Zn(1．4pmol·L-1)下，藻细胞的比生长速率和稳定期生物量分别为0．40d-1和51100cell.ml-1.当Zn2+浓度超过24．4pmol·L-1时，提高Zn2+浓度(181．6pmol·L-1)，藻细胞的比生长速率没有改变。为0．93d-1,而稳定期生物量则略有下降，但均明显高于低Zn条件下藻细胞的比生长速率和稳定期生物量．Zn限制条件下藻细胞的叶绿素a合成受到影响。藻细胞光合作用需在更高光强下达到饱和．随着Zn2+浓度增加藻细胞光饱和的光合作用速率(Pm)及光合作用效率(a)均明显增大．研究表明，富营养化水体中，高的Zn浓度是一定条件下触发赤潮藻类爆发性增殖的重要因子之一.

Response of Prorocentrum minimum growth to zinc limitation

Studies on the growth and physiological response of red tide alga Prorocentrum minimum to three Zn2+ levels were showed that the specific growth rate and biomass were limited in low Zn(2+)-grown cells (1.4 pmol.L-1, which were 0.40 d-1 and 51,100 cell.ml-1 respectively. The specific growth rate was not significantly different when the Zn2+ concentration in medium was increased over 24.4 pmol.L-1, but there was a slight decrease in biomass; however, both specific growth rate and biomass were much higher than those in low Zn(2+)-grown cells. It was also showed that chlorophyll a synthesis was limited due to Zn2+ deficient, and therefore, the cells became light saturated at higher irradiance under Zn-limited condition. Light-saturated photosynthetic rates (Pm) and photosynthetic efficiency (alpha) increased significantly with increasing Zn2+ concentrations. It was concluded that Zn2+ concentration might be one of the key factors affecting red tide blooms in eutrophication environment.