THE RELATIONSHIP OF LIPIDS WITH LIGHT AND CHLOROPHYLL MEASUREMENTS IN FRESHWATER ALGAE AND PERIPHYTON1
| العنوان: | THE RELATIONSHIP OF LIPIDS WITH LIGHT AND CHLOROPHYLL MEASUREMENTS IN FRESHWATER ALGAE AND PERIPHYTON1 |
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| المؤلفون: | Guillermo E. Napolitano |
| المصدر: | Journal of Phycology. 30:943-950 |
| بيانات النشر: | Wiley, 1994. |
| سنة النشر: | 1994 |
| مصطلحات موضوعية: | Chlorophyll a, Spirogyra, biology, macromolecular substances, Plant Science, Chlorophyta, Aquatic Science, biology.organism_classification, chemistry.chemical_compound, chemistry, Algae, Chlorophyll, Botany, polycyclic compounds, lipids (amino acids, peptides, and proteins), Cladophora, Green algae, Food science, Periphyton |
| الوصف: | Lipid content and lipid class composition were determined in stream periphyton and the filamentous green algae Cladophora sp. and Spirogyra sp, Sterols and phospholipids were compared to chlorophyll a (chl a) as predictors of biomass for stream periphyton and algae. Chlorophyll a, phospholipids, and sterols were each highly correlated with ash-free dry mass (AFDM) (r2 > 0.98). Stream periphyton exposed naturally to high light (HL) and low light (LL) had chl a concentrations (μg chl a-mg−1AFDM) of 7.9± 0.7 and 12.4 ± 2.9, respectively, while the sterol concentrations of these HL and LL stream periphyton (1.6 ± 0.4) were not significantly different (P > 0.05). Periphyton exposed to an irradiance of 300 μmol photons·m−2s−1 in the laboratory for 60 h had 5.6 ± 0.55 μg chl a·mg−1 AFDM, but the same periphyton exposed to 2% incident light for the same amount of time had 11.0 ± 0.56 μg chl a·mg−1 AFDM. Sterol concentrations in these periphyton communities remained unchanged (1.5 ± 0.3 μg·mg−1AFDM), Similar results (i.e. changes in chl a but stability of sterol concentrations in response to irradiance changes) were also found for Cladophora and Spirogyra in laboratory experiments. Sterols can be quantified rapidly from a few milligrams of algae and appear to be a useful predictor of eukaryote biomass, whereas cellular levels of chl a vary substantially with light conditions. Phospholipids (or phospholipid fatty acids) are considered to be a reliable measure of viable microbial biomass. Nevertheless, phospholipid content varied substantially and unpredictably among algae and periphyton under different light regimes. Irradiance also had a significant effect on storage lipids: HL Cladophora and HL periphyton had 2 × and 5 × greater concentrations of triacylglycerols, respectively, compared to their LL forms. HL and LL algae also differed in the concentration of several major fatty acids. These light-induced changes in algal lipids and fatty acids have important implications for grazers. |
| تدمد: | 1529-8817 0022-3646 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::054d72c35b0a115d0949c529f431eceb https://doi.org/10.1111/j.0022-3646.1994.00943.x |
| حقوق: | CLOSED |
| رقم الأكسشن: | edsair.doi...........054d72c35b0a115d0949c529f431eceb |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15298817 00223646 |
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