Matsuda Yusuke, Satoh Keiichi, Harada Hisashi, Satoh Dan, Hiraoka Yasutaka, Hara Takumi
Department of Bioscience, Kwansei-Gakuin University, 21 Gakuen, Sanda 6691337, Japan.Corresponding author; email:
Department of Bioscience, Kwansei-Gakuin University, 21 Gakuen, Sanda 6691337, Japan.
Funct Plant Biol. 2002 Apr;29(3):279-287. doi: 10.1071/PP01186.
The marine diatom, Phaeodactylum tricornutum Bohlin, is probably one of the most extensively studied marine alga with respect to carbon acquisition and assimilation mechanisms. However, quantitative analyses of HCO3utilization and the detailed process of acclimation of cells from high CO2 to limited CO2 are yet to be done extensively. Suitable molecular markers for this acclimation process are not established, either. Recently, it became clear that the rate of CO2 formation in artificial seawater is about eight times slower than that in freshwater, and thatP. tricornutum cells utilize HCO3 quite efficiently. Despite their great capacity to take up HCO3, the signal controlling photosynthetic affinity for dissolved inorganic carbon has been shown to be CO2 in the medium. Furthermore, light seems to be required for this process. Internal carbonic anhydrase (CA) activity has been shown to be crucial for high-affinity photosynthesis in a number of algae, including marine diatoms. Internal β-type CA, which has been isolated in one strain of P. tricornutum, was clearly shown to be a low-CO2 inducible enzyme. This review paper additionally includes data showing that this CA occurs generally in P. tricornutum species.
海洋硅藻三角褐指藻（Phaeodactylum tricornutum Bohlin）可能是在碳获取和同化机制方面研究最为广泛的海洋藻类之一。然而，关于HCO₃⁻利用的定量分析以及细胞从高CO₂环境适应到有限CO₂环境的详细过程尚未得到广泛研究。适用于此适应过程的分子标记也尚未确立。最近，有研究表明，人工海水中CO₂的形成速率比淡水中慢约八倍，并且三角褐指藻细胞能够非常有效地利用HCO₃⁻。尽管它们具有很强的吸收HCO₃⁻的能力，但控制光合作用对溶解无机碳亲和力的信号已被证明是培养基中的CO₂。此外，这个过程似乎需要光照。在包括海洋硅藻在内的许多藻类中，内部碳酸酐酶（CA）活性已被证明对高亲和力光合作用至关重要。在一株三角褐指藻中分离出的内部β型CA，已被明确证明是一种低CO₂诱导酶。这篇综述文章还包含数据表明这种CA普遍存在于三角褐指藻物种中。
