먹이 生物 Nitzschia closterium W. SMITH의 成長에 미치는 光의 影響

Effects of Light on the Growth of Food Organism, Nitzschia closterium W. SMITH

The draft culturing experiment was carried out in order to examine the effect of light on the growth of the the food organism, Nitzschia closterium, under the combination of three different illuminating time and light intensity. The temperature was kept at 18±2°C during the culturing, the cell number, cell turbidity, dry weight and chlorophyll a content were checked in every 1 to 3 days and expressed as the growth rate, and the metabolic rate was calculated by using the photosynthetic rate data measured at 11 days. The increasing tendency of the cell number and cell turbidity with the culturing period shows the maximum after the inoculation 5 days, and the declining trend after 11 days. The effect of light intensity shows the lowest in 1,000 lux condition and higher in 3,000 lux. The division rate of cell in a day is kept as high level until 5 days, and is markdly fast in case of the longer illuminating time. On the light intensity, the division rate of cell is the lowest in 1,000 lux and the highest in 6,000 lux. The dry weight of cell tends to increase for the whole culturing period regardless of the illuminating time and light intensity. The chlorophyll a content shows the rapid increase tendency in accordance with the light internsity is similar to that of the cell turbidity. Daily photosynthetic rate was showed higher assimilation rate with the longer illuminating time and the stronger light intensity.