Poster Presentation 2-39

Usability of Added Sugars by Endogenous Starch-Fermenting Marine Microalga, Chlamydomonas perigranulata

Koyu Hon-Nami*

Energy and Environment R&D Center

Tokyo Electric Power Company

4-1 Egasaki-cho, Tsurumi-ku

Yokohama 230-8510, Japan

Mitsubishi Kagaku Institute of Life Sciences

11 Minamiooya, Machida

Tokyo 194-8511, Japan

Phone: +81-42-724-6265

Fax: +81-42-724-6316

E-mail: khonnami@libra.ls.m-kagaku.co.jp

Global warming is a worldwide concern. One of its causes is recognized to be anthropogenic increases in atmospheric level of greenhouse gases, including carbon dioxide (CO₂) derived from fossil fuels through combustion. Expansion of CO₂ sink and the reduction of such fuel combustion are essential for principal countermeasures in addition to a direct separation at exhaust sites and following sequestration. Microalgae technology is considered an option for CO₂ abatement with effective CO₂ fixation by photosynthesis. Some microalgae could convert fixation products to valuable substances including fuels and chemicals such as ethanol. The effectiveness of their application depends exclusively upon their abilities to replace modern fuels and/or chemicals widely used at present. A marine microalga, Chlamydomonas perigranulata, was demonstrated to progress fermentation using starch stored in cells through photosynthesis under anaerobic and dark conditions. Fermentation products are ethanol, 2,3-butanediol and CO₂ as well as acetic acid and lactic acid. Recently, usability of added glucose was demonstrated by using ¹³C-enriched glucose and NMR spectroscopy. This paper presents preliminary results of usability of added mono-sugars including D-xylose by C. perigranulata. The resultant possible application of this strain as one a biological CO₂ converter to alternative fuels and chemicals for CO₂ abatement will be discussed.