Ecophysiological strategies for growth under varying light and organic carbon supply in two species of green microalgae differing in their motility. (December 2017)

• Record Type: Journal Article
• Authors: Spijkerman, Elly; Lukas, Marcus; Wacker, Alexander
• Is Part Of: Phytochemistry. Volume 144(2017)
• Page Start: 43
• Page End: 51
• Publication Date: 2017-12
• Subjects: Chlamydomonas acidophila -- Chlorella vulgaris -- Chlorophyceae -- Ecophysiology on freshwater phytoplankton -- Glucose -- Mixotrophy -- Osmotrophy -- Heterotrophy -- Photosynthesis -- Fatty acids; Botanical chemistry -- Periodicals; Biochemistry -- Periodicals; Botany -- Periodicals; Chimie végétale -- Périodiques; 572.2
• DOI: 10.1016/j.phytochem.2017.08.018
• Languages: English
• ISSNs: 0031-9422

Abstract

Abstract: Mixing events in stratified lakes result in microalgae being exposed to varying conditions in light and organic carbon concentrations. Stratified lakes consist of an upper illuminated strata and a lower, darker strata where organic carbon accumulates. Therefore, in this contribution we explore the importance of dissolved organic carbon for growth under various light intensities by measuring some ecophysiological adaptations in two green microalgae. We compared the non-motile Chlorella vulgaris with the flagellated Chlamydomonas acidophila under auto-, mixo-, and heterotrophic growth conditions. In both algae the maximum photosynthetic and growth rates were highest under mixotrophy, and both algae appeared inhibited in their phosphorus acquisition under heterotrophy. Heterotrophic conditions provoked the largest differences as C. vulgaris produced chlorophyll a in darkness and grew as well as in autotrophic conditions, whereas Chl. acidophila bleached and could not grow heterotrophically. Although the fatty acid composition of both phytoplankton species differed, both species reacted in a similar way to changes in their growth conditions, mainly by a decrease of C18:3n-3 and an increase of C18:1n-9 from auto- to heterotrophic conditions. The two contrasting responses within the group of green microalgae suggest that dissolved organic carbon has a high deterministic potential to explain the survival and behaviour of green algae in the deeper strata of lakes. Graphical abstract: Highlights: Two green algae differ in their ecophysiological response to light and glucose. Algae show in-lake survival strategies to varying light and organic carbon supply. Chlorella and Chlamydomonas acclimation strategies are linked to their ecology. Response to heterotrophy was the main deviating characteristics.