稀土元素La和Ce对小球藻生长的影响

Effect of Lanthanum and Cerium on Growth and Physiological Properties of Chlorella vulgaris

摘要:

本文以普通小球藻(Chlorella vulgaris)作为受试藻种，研究了硝酸镧和硝酸铈对其生长的影响，旨在探讨稀土化合物用于小球藻培养的方法和效果。具体实验包括：在藻类培养基中添加不同浓度的稀土硝酸盐，定时取样测定培养物光密度，绘制生长曲线并计算比生长速率(μ)，测定细胞密度最大时的干物质含量、叶绿素含量、类胡萝卜素含量以及可溶性糖含量。通过实验得出：10-3~10-6 mM的稀土元素在培养早期能够促进小球藻的细胞增殖，但随着培养时间延长促进作用减弱，比生长速率与对照组的差异逐渐缩小；10-3 mM La可将叶绿素a和b的含量分别提高24.46%和28.51%，10-4mM的Ce可将其分别提高50.76%和38.92%；此外，10-3mM La或Ce可分别将胞内可溶性糖含量提高13.83%和34.88%。上述研究表明：在藻类培养基中添加一定浓度的La或Ce，可以加快小球藻细 胞的早期增殖速度，缩短获得最大生物量的培养时间，同时还可提高叶绿素、类胡萝卜素以及可溶性糖的含量，但是两种稀土元素的效应浓度范围略有差异。

Abstract:

In order to study the biological effects of La and Ce on Chlorella vulgaris, growth curve was plotted, and the biomass, contents of chlorophyll a and b, carotenoid and soluble sugar were tested. The results showed that La and Ce at 10-3~10-6 mM stimulated algae cell proliferation at early stage, and their growth promoting effect weakened as time was increased. Compared with blank control, the contents of chlorophyll a and b increased by 24.46% and 28.51%, respectively, when cultured with La at 10-3 mM while they were raised by 50.76% and 38.92%, respectively, with Ce at 10-4 mM. In addition, 10-3 mM La and Ce could increase the soluble sugar content by 13.38% or 34.88%, respectively.. In conclusion, certain amounts of La or Ce could efficiently promote the algae cell growth at early stage, shorten the lag stage, and increase the contents of chlorophyll and soluble sugar.