| 摘要: |
| 利用错流超滤技术提取天然胶体，研究了胶体的有机碳浓度、粒径和来源对海水小球藻(Chlorella spp.)、亚心形扁藻(Platymonas subcordiformis)和球等鞭金藻(Isochrysis galbana)生长的影响。结果表明，当粒径为10kDa—0.2μm、胶体有机碳浓度为4.8—238.4μmol/L时，胶体使小球藻、扁藻和金藻的生长率分别提高了4.0%—7.0%、19.1%—28.9%和2.9%—8.7%。海水小球藻生长率的相对增长百分数(Y)值与胶体有机碳浓度(CCOC)呈线性正相关；亚心形扁藻和球等鞭金藻的Y与CCOC呈多项式相关；胶体对扁藻生长的刺激作用大于球等鞭金藻和海水小球藻。粒径为10kDa—0.2μm的胶体对3种藻的促进作用大于1—10kDa的胶体。河口、河流和生源胶体使小球藻的生长率提高1.5%—14.1%，不同来源的3种胶体对海水小球藻的促进作用依序是河流胶体>生源胶体>河口胶体。以上结果表明，天然胶体含有微藻生长所必需的营养元素，对微藻的生长有显著的刺激作用。 |
| 关键词: 天然胶体 微藻 生长 效应 |
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| 基金项目:国家教育部高等学校骨干教师计划基金资助项目,2005;国家自然科学基金重大研究计划重点项目,90411016号 |
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| THE EFFECT OF NATURAL COLLOIDS ON THE GROWTH OF ALGAE |
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ZHENG Ai-Rong, CHEN Min, Lü’E, YANG Jun-Hong, CHENG Yuan-Yue
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Depart.of Oceanography and Institute of Subtropical Oceanography, Xiamen University, 361005
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| Abstract: |
| Natural colloids are originated from multiple sources from river runoffs, sediment re-suspension, and marine biological processes. Colloids are contained in organic matters in different sizes and concentrations, which would impact phytoplankton growth in different manners. To study the mechanism that would help mariculture and marine pharmaceutical application, we conducted this research on the effect in terms of colloidal organic carbon (COC) concentration on the phytoplankton growth. Water samples were collected from waters near Xiamen (Amoy) of Fujian representing natural river, estuary, and sea water masses, from which natural colloids were abstracted with cross-flow ultrafiltration technique. Phytoplankton samples were algae including Chlorella spp., Platymonas subcordiform is and Isochrysis galbana. Biogenic colloid was isolated from the cultured solution of Chlorella spp.
With the cross-flow ultra filtration technique, the water samples were passed through a 0.2μm pore-size cartridge filter to remove suspended particulate matter, and then ultrafiltrate using a cross-flow ultrafiltration cartridge with a 10kDa or 1kDa hollow-fibermembrane. At the end of ultrafiltration, the colloids in retentate were in sizes of 10 kDa–0.2 μm or 1–10 kDa.
The results showed that the growth rates (k) of three algae increased respectively 4.0%–7.0%, 19.1%–28.9% and 2.9%–8.7% at COC concentrations o f 4.8–238.4 μmol/L and colloidal sizes in 10 kDa–0.2 μm. The percentage of relative increase of growth rate (Y) for Chlorella spp. was directly related to COC concentration, and the relations between Y and COC concentration for P. subcordiformis and I. galbana were polynomial. The stimulation of marine colloids on P. subcordiformis is greater than I. galbana and the Chlorella spp. Results also showed that the growth rates(k) of three algae in the colloids in sizes of 1–10kDa increased respectively by 11.6% , 25.4% and 3.2% , and in the colloids sized in 10 kDa–0.2 μm, by 22.5%, 29.5% and 4.5%. The values of k for the three algae in the presence of colloids in sizes of 10 kDa–0.2 μm were 1.9, 1.2 and 1.4 times greater than that in sizes of 1–10 kDa. This means that bioactivity of high molecular weight marine colloids are higher than those in low molecular weight. The adding of estuarine, riverine and biogenic colloids caused 1.5%, 14.1% and 9.7% enhancement in growth rate of Chlorella spp. respectively. The maximum growth stimulations of Chlorella spp. by the three colloids was riverine colloids, biogenic colloids and estuarine colloids in descending order. It is clear that natural colloids contain nutrients required in growth of phytoplankton, and they can markedly boost the algae growth and be uptaken by algae. |
| Key words: Natural colloids, Algae, growth, Effect |
