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

潮间带具有多种功能，例如防洪、净化废物、为植物或浮游生物补充营养以及渔业生产。这些功能得到了潮间带沉积物中微生物的支持。胞外酶是由微生物分泌或通过细胞裂解释放出来的，它催化有机物质水解成元素营养物质。在以前的研究中，我们发现在沉积物中添加蛋白质显著提高了磷酸酶的活性。为了了解蛋白质负荷量与磷酸酶活性诱导之间的生物联系机制，有必要对潮间带沉积物中负荷量蛋白质的酶降解过程进行表征。为此，我们建立了一种利用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法(十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法)从潮间带沉积物中分离蛋白质片段的方法。用该方法研究了卡莫河土壤中蛋白质的水解酶活性和水解物。结果表明，中游和河口水域的土壤具有较高的蛋白酶活性。然而，沉积蛋白水解酶产生的多肽图谱不同，表明潮滩沉积物具有特定的水解酶。我们还报道了一种在Heussen和Dowdle报告的改进方法的基础上发现潮滩沉积物中涉及的蛋白酶的电泳法。利用该方法，我们明确了潮滩中存在的几种蛋白酶。此外，还发现，通过蛋白质负载表现出磷酸酶高诱导作用的区域，其沉积物中具有特征的蛋白酶。

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.