. 2005, 23(0512): 37-40.
The effects of three nitrogen sources such as ammonium chloride, urea and potassium nitrate, and two phytohormones such as indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA), on the growth and the content of lutein in Chlorella sp were investigated under light condition, respectively. The results showed that when glucose and potassium nitrate were used as the sole carbon and nitrogen sources, the rapid and continuous growth of Chlorella sp was achieved. If urea was used as the sole nitrogen source, the growth of Chlorella sp was distinctly slow. Using ammonium chloride as the sole nitrogen source, the growth of Chlorella sp could be apparently inhibited by the rapid decrease of pH of culture solution. Compared with urea and ammonium chloride, potassium nitrate was the best nitrogen source to promote biosynthesis of lutein by Chlorella sp, and the yield of lutein in dry algal cells could reach 0.85mg/g. In the presence of glucose and potassium nitrate, the growth of Chlorella sp could not be accelerated, on the contrary, the biosynthesis of lutein was inhibited by IAA or IBA, respectively.
