赤潮過鞭毛藻Ｐｒｏｒｏｃｅｎｔｒｕｍ ｔｒｉｅｓｔｉｎｕｍの増殖生理

Abstract

Physiological growth characteristics of Prorocentrum triestinum SCHILLER (Dinophyceae), a red tide phytoplankton, were examined in axenic clonal cultures.P. triestinum incubated in ASP12 NTA was found to multiply during the early light period under a light-dark cycle and to require light intensity higher than 6, 000lx for normal growth. The organism preferred high temperature and salinity, and resisted a wide range of pH. Optimal temperature, salinity, and pH value for growth were 20-30°C, 31.5-35.0‰, and 6.5-8.5, respectively. The level of nitrate to maximize the final cell density was about 1.0mg at/l, but the growth rate saturated at a lower level of 0.01mg at/l. The organism utilized glycerophosphate as well as inorganic phosphate as phosphorus sources. The optimal PO4-P concentration maximizing its cell yield was 0.1mg at/l, and the growth rate saturated at 0.005mg at/l PO4-P. The organism required vitamin B12 essentially for growth; its half-saturation constant was 0.36ng/l. The vitamin B12 level to maximize both growth rate and cell yield was about 4ng/l. The maximum specific growth rates under the above optimal growth conditions were 0.63-0.95 d-1.