多变鱼腥藻在不同氮源培养条件下光能转换效率的研究

依公式PE=KY，其中K等于生物量的热值(每克干重千卡)，Y等于产率即每吸收千卡光能所产生的生物量的干重，测试了在无氮和有结合氮培养下的多变鱼腥藻(Anabaena variabilis)的光能转化效率。结果指出在无氮培养下的最高PEN2为8．1％，在结合氮(NH4Cl)培养下PENH =4+为5.8％。对这种差异性作了简要讨论。

Assessment of Light Energy Conversion Efficiency of An Algal Culture, Anabaena variabilis, in Different Nitrogen Source

Light energy conversion efficiency of an algal culture was determined according to the equotion of PE=KY, in which K=the calorific value of the biomass (Kcal per g dry weight), and Y=the growth yield, i.e. the amount of dry cells biomasss produced per Kcal light energy absorbed. The culture was performed in a 10 liters glass fermentor with continuous illumination, equiped with a sensor tube for measuring cell concentration in the medium. Kettering radiometer was used for light energy measurement. When cells were grown in the absence of combined nitrogen, the growth yield YN2=0.013, based on 6.44 for the calculated calorific value of the biomass, thence the maximum PEN2 was 8.1%; while the cells were grown on combined nitrogen (NH4CI) medium, the growth yield YNH4, calorific value of the biomass KNH+4 and the maximum PENH+ were 0.008, 6.74 and 5.8% respectively.