Development of a Portable Incubation Chamber for Microalgae using Light Emitting Diodes

建立世界各地的海洋微藻克隆培养体系是研究全球性有害海洋微藻生物学、生理生态学和生化特性的基础。但由于受有害微藻影响的地区往往是沿海欠发达地区，远离配备有培养设施的先进实验室，因此培养设施的建立有时很困难。发光二极管（Light Emitting Diode，LED）作为照明光源，具有体积小、安全、耗电少等优点。在LED发出的红光、绿色和蓝光下，各种甲藻和硅藻显示出与自然光相当的平稳生长。红壳异囊藻（Heterocapsa coculum quama）在红光下生长较好，而亚历山大藻（Alexandrum spp）在蓝光下生长较好。不同的物种在最佳生长条件（强度和颜色）上表现出较小的差异，这可能来自物种对LED光的适应性差异。应该找到在光合色素吸收区域中的最佳光谱输出以使用LED的非常窄的光谱输出。虽然可以使用具有热控制器的Peltiert模块将温度调节在10摄氏度和30摄氏度之间的期望温度，但是所需的电功率很高，并且连续使用调节器可能导致腔室的容量和电池的维护成本的问题。根据这些结果，成功地制造了腔室（30 × 20 × 20 cm），并用于将微藻从菲律宾和泰国转移到日本，结果良好。这种便携式培养箱能够在处理和现场工作期间维持活细胞，以便可以从更广泛的位置建立更多的有害微藻培养物。

It is fundamental to establish clonal cultures from various part of world for study on biological, ecophysiological and biochemical features of harmful marine microalgae which are thought to have spread globally. But the culture establishment is sometimes difficult, because areas affected by the harmful microalgae are often under-developed coastal area and far from sophisticated laboratories equipped with culturing facilities.This study aimed to develop a Portable incubation chamber furnishing temperature and light control devices. The light resource is obtained by Light Emitting Diodes (LEDs) and it poses many advantages on its smaller size, safety and low electric consumption. Various dinoflagellates and diatoms shows smooth growth comparable to natural light under red, green and blue lights from the LEDs. A dmoflagellate Heterocapsa cocularisquama grows well under red light, and Alexandrium spp under blue light. Different species shows small variation on optimum light condition (strength and color) for the highest growth rate, and it may come from difference of adaptability of species to lights from LEDs. Optimal spectra output in the region of photosynthetic pigment absorption should be found to use the very narrow spectrum output of LEDs. While the temperature could be regulated at a desired temperature between 10 and 30 degree in Celsius using a Peltiert module with a thermo controller, necessary electrical power is high and continuous use of the regulator may cause problem on the capacity of the chamber and maintenance cost of a battery. From these result a chamber (30x20x20 cm) was successfully made and used with good results for transfer of microalgae from the Philippines and Thailand to Japan. This portable incubation chamber enables the maintenance of living cells during handling and field work so that more cultures of harmful microalgae can be established from much wider location.