氮源对小球藻光合作用和色素积累的影响

本文研究了自养培养条件下尿素、NH4NO3、(NH4)2SO4和NaNO3四种氮源对小球藻(Chlorella sp.TCCC45058)生长、光合作用以及叶绿素a产率的影响。实验结果显示,NaNO3是Chlorella sp.TCCC45058生长的最佳氮源,以NaNO3为氮源时得到最高细胞密度4.1×107个/mL;而尿素对藻细胞色素积累最有利,最高叶绿素a产率达到21 mg/g。培养过程中,不同氮源会对培养液pH造成不同影响,以NaNO3为氮源时,随着NO3-的消耗培养液pH会出现显著的上升;以(NH4)2SO4为氮源时pH呈下降趋势;而尿素和NH4NO3则不会对其产生明显影响。将pH维持在中性不会对各组氮源培养效果产生显著影响,因此实际生产中无需对培养基pH做全程控制。

Effects of Nitrogen Source on Photosynthesis and Pigment Accumulation of Chlorella sp. TCCC45058

In the study,effects of four kinds of nitrogen source(carbamide,NH4NO3,(NH4)2SO4 and NaNO3) on biomass,photosynthesis and Chlorophyll A productivity of Chlorella sp.TCCC45058 under autotrophy condition was investigated.The highest cell density(4.1×107/mL) of Chlorella sp.TCCC45058 was acquired when NaNO3 was used as nitrogen source.The optimal nitrogen source for pigment accumulation of Chlorella sp.TCCC45058 was carbamide,with which the highest Chlorophyll A productivity of cell was found as 21 mg/g.Different nitrogen source showed varied influences on medium pH.When NaNO3 was used as nitrogen source,medium pH rose significantly with consuming of NO3-.Use of(NH4)2SO4 as nitrogen source resulted in reduced medium pH.Carbamide and NH4NO3 had little effect on it.When medium pH was controlled at neutral,the result of culture has not improved.Therefore,it was unnecessary to adjust medium pH throughout the cultivation.