원문정보
초록
영어
Microalgae are known to exhibit circadian rhythms. The daily light/dark cycle is of major environmental factor to photosynthetic microorganism. Microalgae deposit energy in form of starch and lipid by utilization of the inexhaustible energy resources from sun light and water with low energy requirement during light phase. At night, in contrast, they utilize their transformed chemical energy for growth and cell division. The objective of this study is to figure out the effect of circadian cycle on growth, nutrient utilization, photosynthesis and lipid accumulation in microalgae Chlamydomonas reinhardtii.2L flat-panel type photobioreactor with front and back windows providing a light-path of 30 mm was established for cultivation. One white LED panel – on back window – provided Illumination. A user-programmed control system was introduced to operate batch and continuous cultivation system as well as L/D cycle. For the preliminary investigation, microalgal culture were exposed to light/dark fluctuations, i.e. 24:0, 16:8, 12:12, 8:16 and 0:24 (hours of day:night), in flask scale.The result demonstrated that growth and lipid content were enhanced at prolonged exposure time of light phase.