| 摘要: |
| 于1998年3月在青岛太平角采集条斑紫菜，在室内光照强度为120μE/(m2s)的培养架上培养，通过测定其光合作用引起密闭海水体系PH值及无机碳浓度的变化，借助于各种无机碳利用的抑制剂（Az,Van,DIDS,SITS）对其无机碳利用机制进行了研究。结果表明，(1)条斑紫菜可间接吸收HCO3-。胞外碳酸醉酶（CA）催化HCO3-水解成CO2扩散进入胞内是条斑紫菜无机碳利用的主要形式，占全部无机碳利用的73%以上。Az是胞外CA的抑制剂，可直接检测胞外CA的存在，它不能透过细胞膜。(2)条斑紫菜可依赖于细胞膜上ATP酶对HCO3-直接转运。但未发现带III蛋白（band 3 Protein）及 Na+/ HCO3-协同转运系统的参与。(3)条斑紫菜PH值补偿点为9.83，CO2补偿点为0.04μmol/L。 |
| 关键词: 条斑紫菜 无机碳 间接吸收 直接转运 碳酸酐酶 |
| DOI：10.11693/hyhz200003003003 |
| 分类号: |
| 基金项目:国家“九五”科技攻关项目，96－C01－05－01号 |
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| INORGANIC CARBON UTILIZATION BY PORPHYRA YEZOENSIS UEDA |
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YUE Guo-feng, ZHOU Bai-cheng
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Institute of Oceanology, The Chinese Academy of Sciences, Qingdao266071
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| Abstract: |
| The mechanisms of inorganic carbon utilization were studied on the red macroalga Porphyra yezoensis Ueda (collected in the Taiping Bay Qingdao in Mar. 1998) by pH drift technique in a closed system by means of various inhibitors: Acetazolamide (Az), Vanadate (Van), 4′,4′-diisothiocyanatosilbene-2.2-disulfonic acid (DIDS) and 4-acetamido-4′-isothiocyano-2,2′-stibene-disulfonate (SITS). The results indicate that: (1) Porphyra yezoensis can uptake HCO3- indirectly. Inorganic carbon utilization of Porphyra yezoensis can be strongly inhibited by 100μmol/L Az which inhibits external CA and regain its full photosynthetic capacity after rinsed three times. Dissolver inorganic carbon was reduced 0.41mmol/L in two hours due to photosynthesis and only 0.11mmol/L by addition of Az. Hence, external carbon anhydrase dehydrating HCO3- to CO2 is the main pathway of inorganic carbon utilization by Porphyra yezoensis, accounting for at least 73 percentage of total inorganic carbon acquisition. External CA can be detected simply by Az which cannot penetrate the plasma membrane. (2) Porphyra yezoensis can also transport HCO3- directly dependent-ATPase as viewed by Van and DIDS inhibition. Band three protein and Na+/ HCO3- transport system have not been found involving in the direct HCO3- transportation since SITS has no affection on carbon acquisition. (3) Porphyra yezoensis has a higher pH compensation point and a lower CO2 compensation point: 9.83 and 0.04μmol/L, respectively. |
| Key words: Porphyra yezoensis Ueda, Inorganic carbon, Indirect uptake, Direct transportation, Carbonic anhydrase |
