MURASE Haruhiko Osaka Prefecture University, Graduate School of Life and Environmental Science, Professor, 生命環境科学研究科, 教授 (20137243)
NAKANO Yoshihisa Osaka Prefecture University, Graduate School of Life and Environmental Science, Professor, 生命環境科学研究科, 教授 (20081581)
MORIO Yoshinari Mie University, Graduate School of Bioresources, Associate Professor, 大学院生物資源学研究科, 助教授 (90273490)
洞口 公俊 ヤンマー株式会社, 顧問研究員
|Budget Amount *help
¥12,300,000 (Direct Cost : ¥12,300,000)
Fiscal Year 2005 : ¥2,800,000 (Direct Cost : ¥2,800,000)
Fiscal Year 2004 : ¥2,800,000 (Direct Cost : ¥2,800,000)
Fiscal Year 2003 : ¥6,700,000 (Direct Cost : ¥6,700,000)
1.Culture of Microalgae for Food
Annual production by coastal fisheries reduced by about half during the seven years from the year 1989. Therefore resource management of coastal fisheries, which require the sustainable reproduction of marine animals, is desired, and a high efficiency technology has to be developed for the production of microalgae as food for the seedlings of marine animals.
The mass production of micro algae as food is greatly dominated by the photosynthetic activity of algae and the lighting conditions, within culture solution used. Hence a mass production system of microalgae using artificial lighting was developed. To save electrical consumption by lamps, the photosynthetic photon flux density(PPFD) within the culture solution was increased by increasing the cell concentration of the solution. For the cultivation of oyster seedlings, we designed the Akkeshi-Cho Oyster Seedlings Research Center. In the Research Center,12 million oyster seedlings per year were able to b
e cultivated by means of a mass production system which produced micro algae of 4 t solution(8.6×106 cells ml-1) per day, in 32 culture-solution tanks(one tank volume:500 1) each.
2.Culture of Euglena
We are planning to develop a new food production system using Euglena, a photosynthetic microalgae, replacing higher plants to feed the rapidly increasing global population. In this study, we evaluated the quantum yield of Euglena and proved that Euglena is a more effective food source than higher plants. As a result, we found that the optimal light conditions of the white fluorescent lamp for the quantum yield of C0_2 fixation was 30 μmol m^<-2> s^<-1>, aerated with the addition of 10% C0_2. We found that the optimal light conditions of LEDs were 30 μmol m^<-2> s^<-1>, aerated with the addition of 10% C0_2, as well as a red : blue photon ratio of 9 : 1. The QY of Euglena under LED light conditions reached 14%, higher than that of higher plants(under 11%, theoretically). We concluded that the quantum yield of Euglena was greater than that of higher plants.
We will further investigate other basic data of Euglena as a food production system. Under the C0_2 concentration of 0.04 %, vitamin contents in Euglena cultured in blue light were higher than those in other LED light conditions. Whereas under the C0_2 concentration of 10 %, vitamin contents in Euglena cultured in blue light were AsA 231 μg 10^9 cells-1,α-toc 221 μg 10^9 cells-1,β-car 208 μg 10^9 cells-1,respectivery, lower than those in ordinary air conditions(with 0.04 % C0_2). In addition, vitamin contents in Euglena cultured in blue light under the CO_2 concentration of 0.04 % were also compared with those in other foods that are more popularly used as vitamin sources. It was concluded that Euglena would be good vitamin source when they are cultured in blue light under the ordinary air condition(with CO_2 concentration of 0.04 %) Less