Study on the Effects of N,P,Fe-EDTA and Mn on the Growth of a Red Tide Diatom Chaetoceros curvisetus

An orthogonal designing method was used to study the effects of N,P,Fe-EDTA and Mn on the growth of a ride diatom Chaetoceros curvisetus.The experiment consisted of sixteen groups,for which we selected four levels for N,P and Fe-EDTA and two levels for Mn respectively.We analysed the variance for cell density,growth rate and generation time.The result shows that P and Fe-EDTA remarkably enhance the maximum cell density and growth rate of C.curvisetus.N can also affect its growth but Mn has not apparently effect.It is concluded that P has the most remarkable enhancing effect on the growth of C.curvisetus.The effecting order is PO4-P Fe-EDTANO3-NMn.Meanwhile,we obtained the range of phosphorus concentration and chelate iron concentration for the growth of C.curvisetus are 1 mmol/L～2 mmol/L and 5 μmol/L～10 μmol/L respectively.The most optimal combination of culture solution for the growth of C.curvisetus is 1 mmol/L nitrogen concentration,2 mmol/L phosphorus concentration and 10 μmol/L chelate iron concentration.Comparing the result obtained in the present study with those from previous studies elsewhere,it appears that C.curvisetus has a large storage capacity for Manganese.