季节性缺氧环境底栖动物对微藻脂类化合物降解影响模拟研究
发布时间：2019-03-12 16:37
【摘要】：本研究以中国近海典型赤潮藻中肋骨条藻(Skeletonema costatum)为研究对象，考察季节性缺氧环境下底栖动物对脂类标志物在沉积物中降解的影响。通过对比不同氧饱和度模拟培养体系中中肋骨条藻在有/无刀额新对虾(Metapenaeusensis)幼体活动背景下的降解过程，追踪中肋骨条藻中主要脂肪酸和中性脂在100%、50%、25%和0%的氧饱和度体系中的降解行为。研究结果表明： (1)底栖动物的扰动作用能够转移表层沉积物中的藻源脂类化合物至次表层沉积物和悬浮颗粒中，改变其在沉积物中的分布。随含氧量的降低，底栖动物扰动作用减弱，对藻源脂类化合物的转移作用减弱。具体而言，100%氧饱和度体系，脂肪酸和中性脂在实验组表层沉积物中的含量迅速减少，被大量转移到次表层沉积物和悬浮颗粒中；50%氧饱和度体系中，底栖动物的扰动作用转移脂类化合物的量明显减少，悬浮颗粒物只在实验初期产生并在其中检测到脂类化合物。虽然50%样饱和度体系中底栖动物向次表层转移微藻较少，但其中的藻源脂类化合物含量与100%氧饱和度体系相差不大，主要是由于50%氧饱和度体系次表层沉积物中的藻源脂类化合物降解缓慢造成的。25%和0%氧饱和度体系中没有悬浮颗粒物产生，在次表层沉积物也没有检测到藻源脂类化合物。 (2)100%氧饱和度体系中底栖动物的活动能够明显加快脂类化合物在沉积物中的降解。实验组藻源脂肪酸降解速率常数kav约为对照组的1.2-1.7倍。底栖动物对饱和脂肪酸14:0和16:0降解的促进作用更为明显。实验组中性脂kav为对照组的2.2-2.8倍。在50%氧饱和度体系的中度缺氧体系中，刀额新对虾幼体活力逐渐减弱，最终死亡，死亡之前的扰动增加了有机物在次表层沉积物中的埋藏并降低了脂类化合物的降解速率，，因而实验组脂肪酸和中性脂的降解速率常数kav小于或接近对照组。25%和0%氧饱和度体系中，实验组和对照组脂类化合物降解速率常数kav相近，在这种严重缺氧和无氧环境中，底栖动物迅速死亡，对脂肪酸和中性脂降解的影响可以忽略，脂肪酸和中性脂的降解主要受微生物影响。 (3)除了底栖动物的扰动，氧化还原环境和化合物自身结构也是影响脂类化合物降解速率的重要因素。不同环境中，氧饱和度降低时中性脂和脂肪酸降解速率常数kav均减小，但中性脂减小幅度更大。同一体系中结构不同的脂肪酸降解速率常数kav差别明显，不饱和脂肪酸20:5和16:1(7)的kav值大于饱和脂肪酸，20:5含有的双键较多，其kav值也较大，底栖动物的存在没有改变这一规律。多不饱和脂肪酸降解速率常数在四种体系中总的变化范围0.25~0.52d-1，饱和脂肪酸降解速率常数范变化围为0.11~0.34d-1，表明不饱和双键对脂肪酸自身降解影响显著。氧饱和度相同的对照组或实验组培养体系中，分子结构不同的中性脂化合物降解速率常数相差不大，表明底栖动物的存在减弱了中性脂化合物分子结构对其自身降解的影响。
[Abstract]:In this study, the effects of benthic animals on the degradation of lipid markers in the sediment were investigated by using the Skeelleonema costatum as the research object in the typical red tide algae in China. The degradation of the main fatty acid and the neutral lipid in the system of the oxygen saturation of 100%,50%,25% and 0% of the main fatty acids and the neutral lipids in the rib-strip algae was tracked by comparing the degradation process of the middle rib and the neutral fat in the culture system of the different oxygen saturation simulation culture system under the background of the activity of the new penaeus vannamei (Metapenaea). The results show that: (1) The disturbance of benthic animals can transfer the algal source lipid compounds in the surface sediments to the subsurface sediments and suspended particles to change their distribution in the sediment B. With the decrease of the oxygen content, the disturbance of the benthic animal is weakened, and the transfer function of the algae-derived lipid compound is reduced. Weak. In particular, the content of the 100% oxygen saturation system, the fatty acid and the neutral fat in the surface sediments of the experimental group is rapidly reduced, and is transferred to the secondary surface sediment and the suspended particles in a large amount; in the 50% oxygen saturation system, the disturbance of the benthic animals is obviously reduced by the disturbance of the benthic animals. Less, suspended particulate matter was generated only at the beginning of the experiment and a lipid combination was detected in that 50% sample saturation system, the content of the algal source lipid compound and the 100% oxygen saturation system do not differ from that of the 100% oxygen saturation system, The large, mainly due to the slow degradation of the algal source lipid compounds in the 50% oxygen saturation system subsurface sediments. There was no suspended particulate matter in the 25% and 0% oxygen saturation system, and the algae source lipid combination was not detected in the subsurface sediment (2) The activity of the benthic animal in the 100% oxygen saturation system can significantly increase the lipid compound in the sediment The degradation rate of the fatty acid in the experimental group was about 1.2-1 in the control group. .7-fold. The effect of benthic animals on the degradation of saturated fatty acids 14:0 and 16:0 In the experimental group, the neutral lipid, kav, was 2.2-2 in the control group. In the medium-anoxic system of 50% oxygen saturation system, the activity of the penaeus vannamei is gradually reduced, the final death and the disturbance before the death increase the burial of the organic matter in the secondary surface sediment and reduce the drop of the lipid compound. The rate of degradation of fatty acid and neutral fat in the experimental group was less than or close to that of the control group. In the 25% and 0% oxygen saturation system, the degradation rate constant of the lipid compounds in the experimental group and the control group was similar to that of the control group. In this severe hypoxia and oxygen-free environment, the benthic animal was not The effect of rapid death on the degradation of fatty acid and neutral fat can be neglected, and the degradation of fatty acid and neutral fat is mainly affected by microgeneration. (3) In addition to the disturbance of benthic animals, the oxidation and reduction environment and the structure of the compounds are also the effects of the degradation rate of lipid compounds. In different environments, both the neutral fat and the fatty acid degradation rate constant, kav, decreased when the oxygen saturation was reduced, but the neutral lipid decreased. In the same system, the different fatty acid degradation rate constants kav are different, the kav value of unsaturated fatty acid 20:5 and 16:1 (7) is higher than that of saturated fatty acid,20:5 contains more double bonds, the kav value is larger, and the existence of benthic animals is not changed. The change of the rate constant of the polyunsaturated fatty acid in the four systems is from 0.25 to 0.52 d-1, and the change of the rate constant of the saturated fatty acid is in the range of 0.11-0.34 d-1, indicating that the unsaturated double bond can reduce the fatty acid itself. In the control group of the same oxygen saturation or the culture system of the experimental group, the degradation rate constant of the neutral lipid compound with different molecular structure was not small, indicating that the existence of the benthic animal weakened the molecular structure of the neutral lipid compound to its own.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：X55;Q958.8
本文编号：2438965
[Abstract]:In this study, the effects of benthic animals on the degradation of lipid markers in the sediment were investigated by using the Skeelleonema costatum as the research object in the typical red tide algae in China. The degradation of the main fatty acid and the neutral lipid in the system of the oxygen saturation of 100%,50%,25% and 0% of the main fatty acids and the neutral lipids in the rib-strip algae was tracked by comparing the degradation process of the middle rib and the neutral fat in the culture system of the different oxygen saturation simulation culture system under the background of the activity of the new penaeus vannamei (Metapenaea). The results show that: (1) The disturbance of benthic animals can transfer the algal source lipid compounds in the surface sediments to the subsurface sediments and suspended particles to change their distribution in the sediment B. With the decrease of the oxygen content, the disturbance of the benthic animal is weakened, and the transfer function of the algae-derived lipid compound is reduced. Weak. In particular, the content of the 100% oxygen saturation system, the fatty acid and the neutral fat in the surface sediments of the experimental group is rapidly reduced, and is transferred to the secondary surface sediment and the suspended particles in a large amount; in the 50% oxygen saturation system, the disturbance of the benthic animals is obviously reduced by the disturbance of the benthic animals. Less, suspended particulate matter was generated only at the beginning of the experiment and a lipid combination was detected in that 50% sample saturation system, the content of the algal source lipid compound and the 100% oxygen saturation system do not differ from that of the 100% oxygen saturation system, The large, mainly due to the slow degradation of the algal source lipid compounds in the 50% oxygen saturation system subsurface sediments. There was no suspended particulate matter in the 25% and 0% oxygen saturation system, and the algae source lipid combination was not detected in the subsurface sediment (2) The activity of the benthic animal in the 100% oxygen saturation system can significantly increase the lipid compound in the sediment The degradation rate of the fatty acid in the experimental group was about 1.2-1 in the control group. .7-fold. The effect of benthic animals on the degradation of saturated fatty acids 14:0 and 16:0 In the experimental group, the neutral lipid, kav, was 2.2-2 in the control group. In the medium-anoxic system of 50% oxygen saturation system, the activity of the penaeus vannamei is gradually reduced, the final death and the disturbance before the death increase the burial of the organic matter in the secondary surface sediment and reduce the drop of the lipid compound. The rate of degradation of fatty acid and neutral fat in the experimental group was less than or close to that of the control group. In the 25% and 0% oxygen saturation system, the degradation rate constant of the lipid compounds in the experimental group and the control group was similar to that of the control group. In this severe hypoxia and oxygen-free environment, the benthic animal was not The effect of rapid death on the degradation of fatty acid and neutral fat can be neglected, and the degradation of fatty acid and neutral fat is mainly affected by microgeneration. (3) In addition to the disturbance of benthic animals, the oxidation and reduction environment and the structure of the compounds are also the effects of the degradation rate of lipid compounds. In different environments, both the neutral fat and the fatty acid degradation rate constant, kav, decreased when the oxygen saturation was reduced, but the neutral lipid decreased. In the same system, the different fatty acid degradation rate constants kav are different, the kav value of unsaturated fatty acid 20:5 and 16:1 (7) is higher than that of saturated fatty acid,20:5 contains more double bonds, the kav value is larger, and the existence of benthic animals is not changed. The change of the rate constant of the polyunsaturated fatty acid in the four systems is from 0.25 to 0.52 d-1, and the change of the rate constant of the saturated fatty acid is in the range of 0.11-0.34 d-1, indicating that the unsaturated double bond can reduce the fatty acid itself. In the control group of the same oxygen saturation or the culture system of the experimental group, the degradation rate constant of the neutral lipid compound with different molecular structure was not small, indicating that the existence of the benthic animal weakened the molecular structure of the neutral lipid compound to its own.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：X55;Q958.8
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本文编号：2438965
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