Authors: Stefan Sebök Werner B Herppich Dieter Hanelt
Publish Date: 2016/09/02
Volume: 29, Issue: 1, Pages: 381-393
Abstract
Marine macroalgae offer a feasible solution for reducing CO2 emissions by fixing CO2 as algal biomass and thus providing a source of renewable energy The perennial red alga Palmaria palmata was cultivated and supplied with increased CO2 concentrations starting with 22 μmol kg−1 pH 853 to 9770 μmol kg−1 pH 604 Experiments covered test periods of 28 days 7 days and 2 h to examine the possible influence of different treatment durations Biomass productivity over 28 days showed an increased production rate which continuously declined with increasing CO2 concentration After 7 days the productivity was below the controls suggesting a lag phase or necessary adaptation period to elevated CO2 concentrations of more than 7 days Concerning the effects on maximum electron transport rate ETRmax lightharvesting efficiency alpha and light saturation of the photosynthetic electron transport E k a stimulating influence was identified with the effect becoming more significant the shorter the test period was The treatment with elevated CO2 concentrations for 28 days led to a decrease in photochemical efficiency YII and regulated nonphotochemical energy dissipation YNPQ In contrast the treatment duration of 7 days predominantly increased photochemical quenching whereas the 2h treatment resulted in a significant increase in photochemical quenching and in a significant decrease in nonregulated nonphotochemical energy dissipation Hence elevated CO2 concentrations over a prolonged time period interfered more distinctively with the fluorescence quenching ability of P palmata
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