在钝顶螺旋藻的CFTRI培养液中,氮源用硝酸钠(商品纯级化学品),价格较为昂贵,而作为肥料的硝酸钠我省又长期缺货。为此,自1984年起,我们用硝酸铵、碳酸氢铵、硫酸铵、硝酸钾及尿素等肥料来代替硝酸钠进行试验,结果以尿素的效果最佳。但以尿素为氮源,在深层的培养中由于氨挥发慢,会造成培养液中铵离子浓度过高而发生氨中毒现象。为探 In Spirulina platensis CFTRI broth, the nitrogen source is sodium nitrate (commercial pure grade chemicals), the price is more expensive, and the sodium nitrate as fertilizer has long been out of stock in our province. To this end, since 1984, we use ammonium nitrate, ammonium bicarbonate, ammonium sulfate, potassium nitrate and urea and other fertilizers to replace sodium nitrate test, the results of urea to the best effect. However, urea as a nitrogen source in the deep culture due to ammonia volatilization slow, will result in culture medium ammonium ion concentration is too high and ammonia poisoning. For exploration