Environmental and Biochemical Studies on Changes of Phosphatase Activity of Microorganisms in Tideland Sediments.

滩涂具有多种功能，例如，防洪、废物净化、植物或浮游生物的营养补充以及渔业生产。这些功能是由潮滩沉积物中的微生物支持的。胞外酶是由微生物分泌或通过细胞裂解释放的，催化有机物质水解为元素营养素。在以前的研究中，我们发现向沉积物中添加蛋白质显著增强磷酸酶活性。为了获得有关蛋白质负载和磷酸酶活性诱导之间的生物学联系机制的信息，有必要表征潮滩沉积物中负载蛋白的酶降解过程。为此，我们建立了一种利用SDS-聚丙烯酰胺凝胶电泳（SDS-PAGE）分离潮滩沉积物中蛋白酶消化后的蛋白质片段的生化方法。利用该方法研究了卡莫河流域土壤中蛋白质的酶活性及其水解产物。结果表明，长江中游和河口水域的土壤具有较高的蛋白酶活性。但沉积物蛋白酶产生的多肽谱型不同，表明潮滩沉积物具有特异性蛋白酶。我们还报道了一种电泳方法，以揭示蛋白酶参与潮滩沉积物的基础上，由Heussen和Dowdle报道的改进方法。使用该方法，我们澄清了几种蛋白酶在滩涂的存在。此外，据透露，该地区的磷酸酶的高诱导作用的蛋白质负载，有特征蛋白酶在其沉积物。

Tidelands have multiple functions, e.g., flood control, waste purification, nutrient supplementation to plants or plankton and fishery production. These functions are supported by the microorganisms in tideland sediments. Extracellular enzymes, which are secreted by microorganisms or liberated through cell lysis, catalyze hydrolysis of organic materials to elemental nutrients.In previous studies, we showed that the addition of proteins to the sediments significantly enhances phosphatase activity. To obtain information on the mechanism of the biological link between the protein loading and the induction of phosphatase activity, it is essential to characterize the enzymatic degradation process of load protein in the tideland sediments. For this purpose, we developed a biochemical method with SDS-polyacrylamide gel electrophoresis (SDS-PAGE), which could separate protein fragments digested by proteases in the tideland sediments on a polyacrylamide gel. The protease activities and the hydrolytic products of the protein loaded to soils from the Kamo River were studied using the method. The results indicate that the soils from the middle reach and the estuarine water regions have high protease activities. However, the polypeptide patterns produced by sedimental proteases were different, suggesting that tideland sediments have specific proteases. We also reported an electrophoretic method to reveal proteases involved in tideland sediments based on a modified method reported by Heussen and Dowdle. Using the method, we clarified the presence of several proteases in tidelands. Moreover, it was revealed that the regions which show the high induction effect of phosphatase by protein loading, have characteristic proteases in their sediments.