精养池塘水中胞外酶动态特征及与环境因子的相关性

采用荧光模拟底物法监测了精养池塘水中碱性磷酸酶(AP)、β-葡萄糖苷酶(BG)、亮氨酸氨肽酶(LAP)以及脂肪酶(LIP)活性动态变化特征,分析了胞外酶活性在不同粒径生物上的分布,并探讨了池塘水中酶活性与水质理化因子之间的相关性。结果显示:养殖周期内,草鱼池塘水中β-葡萄糖苷酶活性为0.18~1.63μmol/(L·h),亮氨酸氨肽酶活性范围为0.28~1.66μmol/(L·h),碱性磷酸酶活性为0.96~3.49μmol/(L·h),脂肪酶活性范围为1.48~2.68μmol/(L·h)。主成分分析结果表明,池塘水中胞外酶活性呈现明显的月份动态变化。4种典型胞外酶在池塘水中不同粒径生物上的酶活性分布不同。β-葡萄糖苷酶和亮氨酸氨肽酶活性的主要来源是3μm粒径的浮游生物,碱性磷酸酶活性主要来源为0.22μm粒径的游离态,脂肪酶活性主要来源于0.22μm的游离态和3μm粒径浮游生物。养殖池塘水中β-葡萄糖酶活性与NH_4~+-N、TN、TP、IP、COD_(mn)、Chl.a呈极显著正相关,与DO呈极显著负相关;脂肪酶活性与DO呈极显著正相关,与pH呈极显著负相关;亮氨酸氨基肽酶活性与NH_4~+-N、NO-2-N、TN、TP、IP、COD_(mn)、Chl.a呈显著正相关,与T和pH呈显著正相关,与DO呈显著负相关。

Study on dynamic characteristics of extracellular enzyme activity and its correlations with water environmental factors in intensive fishpond

Dynamic change characteristics analysis of alkaline phosphatase ( AP), β - glucosidase ( BG), leucine? aminopeptidase? (LAP) and lipase (LIP) activity were measured by fluorometry simulation of substrate in intensive fish-pond.The distribution in plankton from different size fraction for 4 typical extracellular enzyme were analyzed and the rela-tionships between the activities of extracellular enzyme and environmental factors were discussed.The results showed that the activities of glucosidase in the pond water were 0.18-1.63 μmol/(L·h).The activity ranges of leucine aminopeptid-ase were 0.28-1.66 μmol/(L·h), the activity ranges of alkaline phosphatase were 0.96-3.49 μmol/(L·h) and the activity ranges of lipase were 1.48-2.68 μmol/(L·h).The results of principal component analysis indicated that the ac-tivity of extracellular enzymes in pond water showed significant changes in different months.The distributions of enzyme ac-tivities for 4 typical extracellular enzymes in different grain diameter organisms were different.The main sources of glucosi-dase and leucine aminopeptidase activity were from grain diameter >3 μm size fraction of plankton.The main activities of alkaline phosphatase activities were from grain diameter <0.22 μm detached organisms, and the lipase activities were mainly from grain diameter <0.22 μm and >3 μm size fraction of plankton.There was a significant positive correlations between β-glucosidase activity and NH4+-N, TN, TP, IP, CODmnand Chl.a in cultured pond and negatively correla-ted with DO.The activity of leucine aminopeptidase was significantly correlated with NH4+-N, NO2--N, TN, TP, IP, COD and Chl.a and there was a significant positive correlation with temperafure and pH, and negatively correlated with DO.