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通过一系列培养实验,模拟了有机物在中国近海季节性缺氧环境沉积物-海水界面的降解过程.以中国近海典型的赤潮藻中肋骨条藻(Skeletonema costatum)为研究对象,对中肋骨条藻中的几种典型脂类生物标志物在不同程度缺氧海水-沉积物界面中的降解行为进行追踪.通过分析测定不同培养时间获取的不同含氧体系(氧饱和度100%、50%,25%和0%)中中肋骨条藻4种主要脂肪酸[14:0、16:0、16:1(7)、20:5]的含量,结果表明,在前2~3周4种脂肪酸迅速减少,之后则变化很慢甚至几乎不变.在不同含氧体系中4种脂肪酸的降解存在很大差异,14:0、16:1(7)、20:5经过两个月的培养,在4种不同含氧体系中几乎降解完全,而16:0在4种体系中剩余25%~35%.根据multi-G模型对4种脂肪酸降解进行定量描述,结果表明,每种化合物可以分为降解较快和较慢的部分,各化合物的平均降解速率常数k av范围在0.079~0.84 d-1,14:0与16:1(7)的降解在25%含氧体系中最快,在降解最快的体系中,14:0的k av是最慢体系(含氧50%)的2.3倍,16:1(7)的k av是最慢体系(含氧100%)的1.7倍;16:0的最快降解速率出现在无氧体系中(0.17 d-1),是最慢体系[50%含氧体系(0.079 d-1)]的2.1倍;20:5的降解速率常数则与含氧量呈正相关.结果表明,影响中国近海缺氧海区沉积物-海水界面中中肋骨条藻中脂肪酸降解的因素除了含氧量之外,有机化合物本身的结构和性质以及环境中微生物作用等对其降解也存在着很大影响.
A series of experiments were conducted to simulate the degradation process of organic matter in the sediment-seawater interface of the seasonal anoxic environment in coastal areas of China.With Skeletonema costatum, a typical red tide algae in the coastal area of China, as the research object, The degradation of several typical lipid biomarkers in different oxygen-deficient seawater-sediment interface was followed by analyzing the different oxygen-containing systems (oxygen saturation of 100%, 50%, 25 The results showed that the contents of four major fatty acids [14: 0,16: 0,16: 1 (7), 20: 5] in Skeletonema costatum were significantly higher than those in the first two to three weeks Decreased, and then changed very slowly or almost unchanged in the different oxygen-containing system degradation of four kinds of fatty acids there is a big difference, 14: 0,16: 1 (7), 20: 5 after two months of culture, 4 kinds of oxygen-containing system almost completely degraded, while 16: 0 in the four systems remaining 25% to 35%. According to the multi-G model of four fatty acid degradation quantitative description, the results show that each compound can be divided into Degradation of faster and slower part of the average degradation rate of each compound k av in the range of 0.079 ~ 0.84 d-1, 14: 0 The degradation of 16: 1 (7) was the fastest in the 25% oxygenated system, with the 14: 0 k av being 2.3 times the slowest system (50% oxygenated), the 16: 1 7) has a k av of 1.7 times the slowest system (100% oxygen); the fastest 16: 0 degradation rate is found in anaerobic systems (0.17 d-1) and is the slowest system [50% oxygenated (0.079 d-1)]. The degradation rate constant of 20: 5 was positively correlated with the oxygen content.The results showed that the factors affecting the degradation of fatty acids in Skewtonia ribofacj in sediment-seawater interface in the anoxic sea of China In addition to the oxygen content, the structure and properties of organic compounds themselves and the role of microorganisms in the environment have a great impact on their degradation.