太湖浮游植物细胞裂解速率的酯酶活性法初步研究

Assessing phytoplankton cell lysis rate in Lake Taihu by esterase assay

本研究从2009年8月至2010年10月,每月采集太湖3个不同富营养化湖区水样,运用酯酶活性法,测定了颗粒态酯酶、溶解性酯酶活性以及酯酶衰变周期,估算了太湖浮游植物细胞裂解速率.研究结果表明,太湖颗粒态酯酶活性为0.58～35.15 nmol FDA/(L.h),溶解性酯酶活性为0.55～7.59 nmol FDA/(L.h),酯酶衰变周期为7～75 h,细胞裂解速率为0.02～0.77 d-1,三个采样点细胞裂解速率没有显著差异.颗粒态酯酶活性与叶绿素a浓度之间具有显著的线性关系,说明运用酯酶活性法估算太湖浮游植物细胞裂解速率是可行.此外,叶绿素a浓度与温度变化趋势基本一致,梅梁湾和湖心叶绿素a浓度具有显著差异.贡湖湾叶绿素a浓度与细胞裂解速率之间具有显著的反比例关系,说明细胞裂解速率也是影响太湖藻类生物量的重要因素.

Pbytoplankton lysis rate in three different eutrophic regions of Lake Taihu was measured by the activities of particle and dissolved esterase, as well as the decay rate of the latter, from August 2009 to October 2010. The present results showed that the particulate, dissolved esterase activity, half life time of dissolved esterase, and cell lysis rates ranged from 0.58 - 35.15 nmol FDA/（ L . h） , 0.55 - 7.59 nmol FDA/（ L . h） , 7 - 75 h, and 0.02 - 0.77 d -1 , respectively. No significant differences were found in the cell lysis rates among the three sampling sites. The significant linear relationship between Chl.a concentration and particulate esterase activities suggests that it is feasible to assess phytoplankton cell lysis rate in Lake Taihu by the esterase assay. Furthermore, Chl.a concentration showed the same pattern with water temperature, a significant difference was observed in Chl.a concentration between Meiliang Bay and lake centre. The strong, negative correlation between Chl.a concentration and lysis rate in Gonghu Bay suggests that phytoplankton biomass was affected by the lysis rate in Lake Taihu.