Haematococcus pluvialis is one type of freshwater unicellular microalgae, belonging to the Chlorophyta, Haematococcus. H. pluvialis has high economic value due to its wide variety of nutritional components, including astaxanthin, vitamins, algal polysaccharides, proteins, etc. Current microalgae detection methods are deficient in monitoring the life cycle of H. pluvialis. In this study, we applied the confocal fluorescence microscopy and the fluorescence lifetime imaging microscopy (FLIM) system to observe the different stages of the microalgal cells. The cell morphology and the fluorescence lifetime distributions were obtained for further analysis. The results showed that H. pluvialis had a diameter of about 25μm in the state of flagellated macrozooids (zoospore). When the nutrients in the medium were continuously consumed, the individual cells of H. pluvialis became larger and entered the microzooid stage, whose diameters were around 35μm. The fluorescence lifetime values of H. pluvialis in the macrozooid (zoospore) stage and the microzooid stage were around 700 to 800ps and 1000ps, respectively. The next stage was the palmella stage, in which the diameter of H. pluvialis increased to the range of 40 to 52μm. During this stage, the larger algae began to accumulate red pigment in the center of the cell. Meanwhile, the fluorescence lifetime values near the center of the algal cell increased to around 1300ps, approximately 200ps higher than the values in the periphery of the cells, showing layered properties of H. pluvialis in the palmella stage. In summary, FLIM can provide a real-time quantitative method for monitoring different life stages and cell morphologies of H. pluvialis during its life cycle in a non-destructive way.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.