三角褐指藻光合与生长参数测量方法的研究

A Study on Measurement Methods of Photosynthesis and Growth Parameters of Phaeodactylum tricornutum

三角褐指藻是生产生物柴油的优势藻种,监测其光合和生长参数是利用它们生产生物柴油的关键环节。本研究通过细胞计数对细胞生长量进行监测,利用多激发波长调制叶绿素荧光仪(Multicolor PAM)、NanoDrop紫外分光光度计与荧光分光光度计分别检测叶绿素荧光参数、培养基中硝酸盐含量、细胞叶绿素荧光强度与中性脂相对含量。结果显示细胞密度与叶绿素荧光强度只有在生长期才具有线性关系,达到稳定期后,叶绿素荧光强度显著性下降,此时与细胞密度不成比例;PSII最大光化学量子效率F_v/F_m与叶绿素荧光值比生长速率呈正相关,在整个培养阶段F_v/F_m的变化趋势呈现两次上升与下降的过程;光化学淬灭系数qL在培养过程中呈上升趋势,而相对电子传递速率rETR与实际光合效率Y(II)均呈现先升后降的趋势;培养基中硝酸盐含量消耗到一定程度后保持恒定,不再降低;细胞中性脂相对含量在藻细胞接种1天后稍下降,随后持续上升,并在培养基硝酸盐含量不再下降后继续增加。本研究中光合与生长参数测量得到的相关数据,以及培养基硝酸盐含量和细胞中性脂相对含量测量方法的建立,可以为三角褐指藻实验室培养及其代谢产物积累的研究提供必要的研究基础与检测手段。

Phaeodactylum tricornutum is an excellent microalgae of the biodiesel production,it is obviously necessary to monitor the photosynthesis and growth parameters of microalgae through the culture process. In this study,the cell density was monitored by cell count,and chlorophyll fluorescence parametes,nitrate content in the culture medium,cell chlorophyll fluorescence intensity and neutral fat relative content were detected by using the Multi Color PAM,Nano Drop UV spectrophotometer and fluorescence spectrophotometer,respectively. The results showed that the number of cells and chlorophyll fluorescence intensity had a linear relationship only at the growth phase,after reaching the stationary phase,the chlorophyll content significantly decreased,when chlorophyll fluorescence intensity was not proportional to cell density. The maximum photochemical quantum efficiency Fv/Fm of PSII which showed two ascending and descending processes in the culture stage was positively correlated with the specific growth rate of chlorophyll fluorescence intensity. The photochemical quenching coefficient q L increased in the culture process,while the relative electron transport rate rETR and the actual photosynthetic efficiency Y（II） both showed the trend of rising first and then down. The content of nitrate in the culture medium decreased to a certain extent,and then no longer reduced. The cell neutral fat relative content decreased after 1 day of cell inoculation and then continued to increase after the nitrate content did not decrease any more.In this study,the correlation data of photosynthesis and growth parameters,and the establishment of the method for measuring nitrate content in the culture medium and cell neutral fat relative content,can provide the necessary detection methods and research foundation for the laboratory culture and metabolite accumulation of P. tricornutum.