AUTHOR=Qiao Yaqin , Rong Junfeng , Chen Hui , He Chenliu , Wang Qiang 

TITLE=Non-Invasive Rapid Harvest Time Determination of Oil-Producing Microalgae Cultivations for Biodiesel Production by Using Chlorophyll Fluorescence

JOURNAL=Frontiers in Energy Research

VOLUME=3

YEAR=2015

URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2015.00044

DOI=10.3389/fenrg.2015.00044

ISSN=2296-598X

ABSTRACT=<p>For the large-scale cultivation of microalgae for biodiesel production, one of the key problems is the determination of the optimum time for algal harvest when algae cells are saturated with neutral lipids. In this study, a method to determine the optimum harvest time in oil-producing microalgal cultivations by measuring the maximum photochemical efficiency of photosystem II, also called Fv/Fm, was established. When oil-producing <italic>Chlorella</italic> strains were cultivated and then treated with nitrogen starvation, it not only stimulated neutral lipid accumulation, but also affected the photosynthesis system, with the neutral lipid contents in all four algae strains – <italic>Chlorella sorokiniana</italic> C1, <italic>Chlorella</italic> sp. C2, <italic>C. sorokiniana</italic> C3, and <italic>C. sorokiniana</italic> C7 – correlating negatively with the Fv/Fm values. Thus, for the given oil-producing algae, in which a significant relationship between the neutral lipid content and Fv/Fm value under nutrient stress can be established, the optimum harvest time can be determined by measuring the value of Fv/Fm. It is hoped that this method can provide an efficient way to determine the harvest time rapidly and expediently in large-scale oil-producing microalgae cultivations for biodiesel production.</p>