【作者】 崔鑫；

【导师】 王江涛； 赵卫红；

【作者基本信息】 中国海洋大学 ， 海洋化学， 2005， 硕士

【摘要】 本文利用切向超滤技术分离海洋胶体,探讨了赤潮爆发海区海水中胶体物质对有害赤潮藻生长的影响;利用实验室模拟培养实验研究了微藻培养液中胶体物质的性质及微藻生长的相互影响:并通过两种微藻的培养,对海洋中荧光物质的来源及产生机理有了更深一步的了解。主要结果如下: 1.在胶州湾柔弱几内亚藻(Rhizosolenia delicatula)赤潮暴发海区采集表层海水,利用切向超滤技术分离海洋胶体,对赤潮异弯藻(Heterosigma akashiwo)和中肋骨条藻(Skeletonema costatum)进行室内培养。实验结果表明:柔弱几内亚藻赤潮爆发水体中的胶体物质对赤潮异弯藻的生长起促进作用,而对中肋骨条藻的生长起抑制作用,且随着胶体含量的增加作用均加强。应用非线性拟合技术研究表明,赤潮异弯藻和中肋骨条藻的生长曲线符合Logistic生长模型,由模型得到的两种微藻的最大生长速率和最大生物量进一步说明了柔弱几内亚藻大量增殖期间可能会产生他感物质,这种物质可以促进赤潮异弯藻的生长,但会抑制中肋骨条藻的生长。 2.通过赤潮异弯藻和中肋骨条藻的大体积培养,然后对其培养液进行胶体物质的分级,对不同粒级的胶体浓缩液和超滤液进行了荧光光谱分析,有机碳及碳水化合物的测定,然后在各粒级溶液中对对方藻进行实验室培养,研究微藻培养液中胶体物质的性质及微藻生长的相互影响。 (1)赤潮异弯藻和中肋骨条藻在生长过程中均产生了大量的胶体有机碳,赤潮异弯藻培养液中胶体有机碳占总溶解有机碳的19.5%;中肋骨条藻培养液中胶体有机碳占总溶解有机碳的12.64%。 (2)赤潮异弯藻和中肋骨条藻培养液的荧光光谱中均有类蛋白和类腐殖质荧光峰出现。通过超滤前后荧光光谱图的对比,赤潮异弯藻和中肋骨条藻培养液中类蛋白质荧光物质有一部分是以胶体形式存在,类腐殖荧光物质主要以<1kDa的小分子形式存在。 (3)赤潮异弯藻培养液中1kDa-0.7μm胶体态碳水化合物占到总溶解态碳水化合物的31.8%。中肋骨条藻培养液中1kDa-0.7μm胶体态碳水化合物占总溶解态碳水化合物的8.09%,其大部分是以分子量<1kDa的真溶解态形式存在。更多还原

【Abstract】 In this thesis, cross-flow ultrafiltration have been used to isolate marine colloids,We studied the effect of marine colloidal substance on the growth of micro-algalduring Rhizosolenia delicatula bloom in Jiaozhou Bay; simulated cultivationexperiments in the lab were conducted to evaluate the properties of colloidalsubstances in micro-algal culture medium and their effects on micro-algal growth;in addition, two algal were cultured to test weather phytoplankton are a directresource of dissolved organic matter fluorescence. The main results read as follows:1. Surface water samples were collected in the Jiaozhou Bay where The Rhizosolenia delicatulabloom was observed. The samples were separated into retentate and permeate usingcross-flow ultrafiltration (1kDa). The Heterosigma akashiwo and Skeletonema costatum werecultured in 0%, 50%, 100% proportion of retentate and permeate to study the effect ofcolloidal substance on Microalga growth during R. delicatula bloom in Jiaozhou Bay. Theresults suggested that: the colloidal substances in R. delicatula bloom water canenhanc the growth of H. akashiwo but suppress the growth of S. costatum. Thepromotion and suppression reinforced with the increase of colloid amount. TheLogistic growth model proved a clear and precise description of the cultivationperiod of H. akashiwo and S. costatum, the max growth rate and max cellcalculated by Logistic growth model suggested that R. delicatula can produce anallepothetic substance which promote H. akashiwo growth and suppress S.costatum growth.2. In the present study, colloid concentrates were obtained by using cross-flow filtration system to ultrafiltrate the culture medium of H. akashiwo and S.costatum (which were pre-filtrated by GF/F membrane) successively with three membranes. Fluorescence spectra, dissolved organic carbon(DOC) and total carbohydrate (TCHO) in the pre-filtrate and three retentions and permeates were examined. Then, another micro-algal were cultivated in the pre-filtrate, threeretentions(100kDa-0.7nm, 10-100kDa, 1-lOkDa) and the permeate (<lkDa). From the experiment, Chemical properties of colloids in the culture medium of H. akashiwo and S. costatum and the influence of colloids on the growth of microalga can be investigated.(1) //. akashiwo and S. costatum can secrete a great deal of dissolved organic carbon in their process of growth About 19.5 percent of DOC was COC (>lkDa) in the culture medium of// akashiwo. And 12.64 percent of DOC existed in the colloids in the culture medium of S. costatum.(2) Protein-like and humic-like fluorescence peaks were found in the fluorescence spectra of the filtrate of H. akashiwo and S. costatum. Through the comparison of fluorescence spectra between retentions and permeates, we found that a part of protein-like fluorescence substance exist in the colloidal concentrations, the humic-like fluorescence substance existed mainly in the permeate.(3) A great deal of carbohydrate existed in the culture medium of H. akashiwo, about 31.97 percent of TCHO was colloidal saccharides(CCHO)(>lkDa) . In the secretion of S. costatum, there was 8.09 percent of TCHO was colloidal saccharides(CCHO)(>lkDa).(4) H. akashiwo can secrete a kind of substance which can restrain the growth of S. costatum intensively, hi the colloidal retention of 10-100kDa and l-10kDa, S. costatum didn’t grow absolutely. The growth rate of S. costatum in the colloidal retention of 100kDa-0.7um was slower than the pre-filtrate and permeate.(5) Substance secreted by S. costatum also can restrain the growth of H. akashiwo intensively. In the pre-filtrate and colloidal retention of 100kDa-0.7 urn, H. akashiwo didn’t grow absolutely. The growth rate of//, akashiwo in the colloidal retention of 10-100kDa was slower than the colloidal retention of l-10kDa and the permeate.3. H. akashiwo and S. costatum were cultured to observe the change of fluorescenceduring the growth of the algal, the main results read as follows: (1) Protein-like and humic-like fluorescence increased with growth of//, akashiwo, there were a rapid increases of fluorescence substance in the stationary phase; inthe exponential phase of S. costatum, there were no significant increase of fluorescence, and Protein-like and humic-like fluorescence appeared until the cell number decreased.(2) Protein-like and humic-like fluorescence were significantly correlated with cell number of the exponential phase of H. akashiwo; there were positive correlation in the exponential phase and negative correlation in the contabescence phase between fluorescence and S. costatum cell number. This results suggested that some micro-algal can produce some fluorescence substance in their process of growth, and fluorescence also can be produced by bacteria using non-fluorescent organic matter derived from phytoplankton .更多还原