Japan-based global automotive supplier DENSO Corporation will build a large 20,000 square meter test facility for the culture of Pseudochoricystis ellipsoidea, an oil-producing microalga patented by DENSO. The new facility located in Amakusa, Kumamoto, Japan will be used to perform verification tests needed to establish large-scale microalga cultivation technologies required to improve biofuel production efficiency. The facility will start operations in April, 2016.
DENSO has been working in collaboration with Keio University’s Institute for Advanced Biosciences since April 2008 to produce biofuel extracted from P. ellipsoidea—a fast-growing, vigorous, and easy-to-cultivate microalga, on which DENSO holds patents. Hydrocarbons and triglycerides can be produced photoautotrophically to up to 30% of the dried biomass (Satoh et al.). The hydrocarbon fraction is more than 10 times higher in nitrogen depleted cells.
Satoh et al. also observed fatty acid composition changes and an increase in triglycerides to 82% of total lipid with nitrogen starvation.
In addition, the algae grow rapidly under acidic conditions below pH 3.5—which most protozoan grazers of microalgae may not tolerate—without losing lipid productivity. This suggests that P. ellipsoidea might be suitable for large-scale cultivation in outdoor open ponds for biofuel production.
In a 2015 paper (Kasai et al.), researchers noted that the lipid productivity of P. ellipsoidea could be improved using genetic engineering techniques; however, genetically modified organisms are the subject of regulation. That research team is working to develop a self-cloning-based positive selection system for the breeding of higher lipid yielding P. ellipsoidea.
In June 2010, DENSO completed the facilities at its Zenmyo Plant (Nishio, Aichi Prefecture) for the purpose of extracting and mass producing bio-fuel from P.ellipsoidea, which produces oil similar to light oil inside its cells, and started verification tests.
CO2 and wastewater emitted from the factory was used to cultivate algae in a pool measuring 33,000 liters. This enabled production of 320 liters of light oil per year as well as research into mass-production technology to reduce costs.
|Rendering of the new facility. Click to enlarge.|
DENSO’s new facility will be one of the largest sites in Japan used for this kind of study. DENSO aims to have established large-scale microalga cultivation technologies in the 2018 timeframe.
Yuki Kasai, Kohei Oshima, Fukiko Ikeda, Jun Abe, Yuya Yoshimitsu and Shigeaki Harayama (2015) “Construction of a self-cloning system in the unicellular green alga Pseudochoricystis ellipsoidea” Biotechnology for Biofuels 8:94 doi: 10.1186/s13068-015-0277-0
Akira Satoh, Misako Kato, Katsuyuki Yamato, Mizuki Ishibashi, Hiroshi Sekiguchi, Norihide Kurano, Shigetoh Miyachi (2010) “Characterization of the Lipid Accumulation in a New Microalgal Species, Pseudochoricystis ellipsoidea (Trebouxiophyceae)” Journal of the Japan Institute of Energy Vol. 89 No. 9 pp 909-913 doi: 10.3775/jie.89.909