海洋纤毛虫摄食微型藻类过程中磷的动力学研究

发布时间：2018-02-04 04:57

本文关键词： 纤毛虫微藻 ~(33)P 动力学参数　出处：《厦门大学》2014年硕士论文　论文类型：学位论文

【摘要】：纤毛虫作为微食物环中一个重要的组成部分,是连接微食物环和经典食物链的过渡环节,在海洋微食物网的能量流动、营养元素循环中扮演重要角色。海洋纤毛虫可通过摄食浮游植物同化营养元素磷,纤毛虫排出的磷又可被浮游植物吸收利用,这是海洋中磷再生的一条重要途径,对微食物环甚至整个生态系统中磷元素的循环流动起着重要的作用。然而目前关于纤毛虫吸收、再生磷元素的研究甚少,相关过程的动力学数据亦十分缺乏。本研究选择香港近岸海域一种常见的纤毛虫一游仆虫(Euplotes sp.)为研究对象,用经过放射性同位素33P标记的三种代表性微型藻类,即等鞭金藻(Isochrysis sp.)、自养型小球藻(Chlorella autotrophica)和假微型海链藻(Thalassiosira pseudonana),喂食纤毛虫。研究了不同食物种类、食物浓度条件下磷的动力学过程。获得研究结果如下：1.游仆虫摄食等鞭金藻、自养型小球藻和假微型海链藻时,对磷的同化率分别为14-46%、12-37%和20-41%。各组摄食实验均在四个食物浓度下进行,即0.04、0.16、0.80和4.00 mg C.L-1。在食物充足时,纤毛虫对三种藻类中磷的同化率较低；而当食物相对匮乏时,同化率显著增高。结果表明,所摄食藻的种类对纤毛虫的磷同化率有一定影响,而食物浓度的影响更大。2.游仆虫体内的磷可分为功能型、结构型两类,在磷的排出过程中对应快速排出、慢速排出两个过程,可分别用排出速率常数ke1和ke2描述。摄食不同藻类时,游仆虫对磷的排出速率不同。游仆虫摄食等鞭金藻、自养型小球藻、假微型海链藻后排出磷的ke1和ke2分别为0.87-1.86d-1和0.09-0.38d-1、0.54-2.29 d-1和0.09-0.15 d-1与1.65-1.89 d-1和0.23-0.60 d-1。结果表明,磷在纤毛虫体内的周转速率较高。3.等鞭金藻、自养型小球藻和假微型海链藻对水体中溶解态无机磷(dissolved inorganic phosphorus,DIP)的吸收速率常数为51.71 L.g-1·h-1,23.17 L·g-1·h-1,12.97 L·g-1·h-1；而对游仆虫排出的再生磷(Recycled Phosphorus,RP)的吸收速率常数分别为：16.10 L·g-1·h-1,19.15 L·g-1·h-1,12.98 L·g-1·h-1。RP是由DIP和溶解态有机磷(dissolved organic phosphorus, DOP)共同组成。三种微型藻类对溶解态磷的吸收利用率都很高,而且吸收DIP的效率高于吸收DOP。与之相比,游仆虫吸收DIP的效率较低,实验中游仆虫在6 h内仅能吸收利用水体中1.6%的DIP,吸收速率常数ku1仅为0.38 L·g-1·h-1。而在纤毛虫对再生磷的重新利用的实验中,6 h内纤毛虫对溶解态磷的利用率3.7%,对应的吸收速率常数ku2为0.58L.g-1.h-1。与之相比,纤毛虫对其食物相颗粒态磷(Particle Phosphorus,PP)的利用率为10-34%,远高于其对溶解态磷的吸收。其可能原因是纤毛虫的细胞膜缺乏运输磷的载体,难以从水相直接吸收磷元素。游仆虫是滤食者,其食性使得适当粒径的食物易于被其捕获并摄入体内,磷元素随之被消化吸收。由此可见,海洋纤毛虫释放在水相中的溶解性磷主要被藻类迅速吸收,而后纤毛虫通过摄食藻类来完成对再生磷的重新吸收利用。4.综合所测各项动力学参数,建立了量化纤毛虫摄食三种微型藻类过程中磷元素流动、循环的动力学的模型。模型结果显示,海洋纤毛虫从食物颗粒中同化磷的效率远高于其从水相吸收溶解态磷的效率,食物颗粒态磷是纤毛虫获取生长代谢所需磷的主要来源。当食物匮乏时,纤毛虫可以进行自身调节提高对食物中磷的同化率,从而更好地适应环境。纤毛虫对磷的快速再生作用促进了磷在微食物网中,以致在整个海洋生态系统中的循环,具有重要的生态学意义。
[Abstract]:The microloop ciliates as an important part of transitional link microloop and classical food chain, energy flow in marine microbial food web, plays an important role in nutrient cycling in marine ciliates. By feeding phytoplankton assimilation nutrition element phosphorus, phosphorus and ciliates discharge can be absorbed by the phytoplankton, which is an important way to ocean phosphorus regeneration, circulation of the microloop even the whole ecosystem phosphorus plays an important role. However, on ciliates absorption, regeneration of phosphorus is very little, the kinetic data of related processes is also very lacking. In this study, a selection of Hongkong coastal waters a common ciliate Euplotes (Euplotes sp.) as the research object, by using the three kinds of representative micro algae radioisotope labeled 33P, namely i.galbana (Isochrysis sp .), autotrophic Chlorella (Chlorella autotrophica) and t. pseudonana (Thalassiosira pseudonana), feeding on different types of food. Ciliates, kinetics of food concentration under the conditions of phosphorus. The results obtained are as follows: 1. Euplotes feeding i.galbana, autotrophic Chlorella and t. pseudonana when the rate of phosphorus assimilation, respectively 14-46%, 12-37% and 20-41%. were feeding experiments were conducted in four food concentration, 0.04,0.16,0.80 and Mg C.L-1. in 4 when food is plentiful, ciliate assimilation of three species of algae in the rate of phosphorus is low; and when the food is relatively scarce, assimilation rate increased significantly. The results showed that what kind of food algae phosphorus assimilation rate of ciliates have a certain influence, but phosphorus greater.2. Euplotes in vivo effects of food concentration can be divided into functional structure, type two, in the discharge process of phosphorus in the corresponding rapid discharge, slow Fast discharge two processes, respectively with discharge rate constants of Ke1 and Ke2. Describe the ingestion of different algae, removal rate of phosphorus in Euplotes. Euplotes feeding i.galbana, autotrophic Chlorella, t. pseudonana phosphorus discharged after Ke1 and Ke2 were 0.87-1.86d-1 and 0.09-0.38d-1,0.54-2.29 and D-1 0.09-0.15 D-1 and 1.65-1.89 D-1 and 0.23-0.60 d-1. results showed that the phosphorus in the high turnover rate of.3. in ciliates Isochrysis, autotrophic Chlorella and t. pseudonana of dissolved inorganic phosphorus (dissolved inorganic, phosphorus, DIP) the absorption rate constant was 51.71 L.g-1 - h-1,23.17 L - g-1 - L - h-1,12.97 g-1 H-1; and on the regeneration of phosphorus in Euplotes discharge (Recycled Phosphorus, RP) the absorption rate constants were 16.10 L - g-1 - h-1,19.15 - g-1 - L h-1,12.98 L - g-1 - h-1.RP is composed of DIP and dissolved organic phosphorus (di Ssolved organic phosphorus, DOP) composed of three kinds of micro algae. The dissolved phosphorus absorption rate is very high, and the absorption of DIP DOP. absorption efficiency is higher than the contrast, Euplotes DIP absorption efficiency is low, the middle reaches of Euplotes can only absorb water in 1.6% DIP within 6 h the absorption rate constant, Ku1 is only 0.38 L - g-1 - h-1. in ciliates to use phosphorus regeneration experiments, 6 h ciliates use of dissolved phosphorus was 3.7%, corresponding to the absorption rate constant ku2 was 0.58L.g-1.h-1. compared with that of ciliates on its food phase particles (Particle Phosphorus, P PP) the utilization rate of 10-34%, much higher than the absorption of dissolved phosphorus. The possible reason is the carrier of the cell membrane of ciliates lack of transport of phosphorus, phosphorus absorption to directly from water. Euplotes are filter feeders, feeding the appropriate size of food is easy to make Is the capture and ingestion of phosphorus, followed by digestion and absorption. Therefore, marine ciliates release of dissolved phosphorus in water is rapidly absorbed by algae, and algae to complete the re feeding of ciliates on the regeneration of phosphorus absorption measured by the comprehensive dynamic parameters by using.4., established the three kinds of micro algae feeding ciliates in the process of phosphorus flow circulation dynamics model. Model results show that the efficiency of marine ciliates from food particles in the assimilation of phosphorus absorption efficiency is much higher than that of the dissolved phosphorus from water, food particulate phosphorus is the main source of growth and metabolism of ciliates to obtain required phosphorus. When food is scarce, ciliates can regulate itself to improve assimilation rate of phosphorus in food, in order to better adapt to the environment. The rapid regeneration of ciliates on phosphorus promoted the phosphorus in the microbial food web, so that in the whole The cycle in the marine ecosystem has important ecological significance.

【学位授予单位】：厦门大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：Q178.53

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