Photosynthetic efficiency and carbon partitioning in nitrogen-starved Scenedesmus obliquus

This research focuses on the potential use of Canna hybrida `King Humbert' for removing simazine from contaminated water generated at golf courses and ornamental nurseries. Because of simazine's herbicidal activity, it is important for levels in solution not to exceed plant tolerance levels. Tolerance levels for C. hybrida were determined by dosing plants for 7 d with 0, 0.01, 0.03, 0.1, 0.3, 1.0, or 3.0 mg simazine/L nutrient media. Measurements of 7-d fresh mass production and photosynthetic efficiency (Fv/Fm) were taken. Simazine uptake and distribution within the plant was determined by dosing plants with 2.03 mCi 14C-simazine (0.243 mg/L) for 1, 3, 5, or 7 d. Plant tissues were analyzed by combustion and liquid scintillation counting. Fresh mass production was reduced 66% and 78% for plants exposed to 1.0 and 3.0 mg/L, respectively. Likewise, photosynthetic efficiency was reduced to 66% and 40% of the controls at the same respective concentrations. Plant uptake of simazine accounted for 13%, 34%, 48%, and 65% of the original simazine in the dosing solution after 1-, 3-, 5-, and 7-d exposure, respectively. This simazine was distributed primarily between roots and leaves.

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Studies of the Physiological Basis for Yields Differences. III. Genetic Variation in Photosynthetic Efficiency of Phaseolus vulgaris L. 1

Crop Science ◽

10.2135/cropsci1967.0011183x000700050015x ◽

1967 ◽

Vol 7 (5) ◽

pp. 457-460 ◽

Cited By ~ 36

Author(s):

S. Izhar ◽

D. H. Wallace

Keyword(s):

Genetic Variation ◽

Phaseolus Vulgaris ◽

Photosynthetic Efficiency ◽

Phaseolus Vulgaris L ◽

Physiological Basis

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UV ability to inactivate microorganisms combined with factors affecting radiation

Water Science & Technology ◽

10.2166/wst.1997.0718 ◽

1997 ◽

Vol 35 (11-12) ◽

pp. 107-112 ◽

Cited By ~ 7

Author(s):

A. M. Shaban ◽

G. E. El-Taweel ◽

G. H. Ali

Keyword(s):

Microbial Communities ◽

Uv Radiation ◽

Contact Time ◽

Tap Water ◽

Scenedesmus Obliquus ◽

Morphological Characters ◽

The Other ◽

Bacterial Cells ◽

Dark Repair ◽

Nile Water

In the present study, the effect of UV radiation on the inactivation of a range of microorganisms was studied. Each organism was seeded into sterile tap water and exposed to UV in batch experiments with changing turbidities. In addition, the effect of UV on microbial communities in river Nile water was examined. It was found that 1min contact time (0.5L/min flow rate) was effective against vegetative cells levels almost reaching zero (except with Staphylococcus aureus). On the other hand, spore-forming bacteria, Candida albicans and coliphage were more resistant to UV. This contact time caused coenobia cells in single form with Scenedesmus obliquus while for Microcystis aeruginosa colonies broke into smaller groups. Exposure of Nile water microbial communities to UV showed that yeasts and Aeromonas survived better than the other organisms while in the phytoplankton partial fragmentation occurred in some algal groups. The protective effect of turbidity differed between organisms, with increased contact time under conditions of stable turbidity having no effect on the organisms. At 20 NTU the UV radiation had no effect on the morphological characters of algal cells. In reactivation experiments, it is clear that photoreactivation, and not dark repair, takes place with bacterial cells. Only coliphage had no photoreactivation and dark repair responses although with coliphage and host, both reactivation processes worked well. Moreover, the irradiated algae regained their normal shape after 3 days in suitable media and enough light.

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Primitive techno-economic study of bio-diesel and bio-active compound production from microalgae

Bulletin of the National Research Centre ◽

10.1186/s42269-020-00383-z ◽

2020 ◽

Vol 44 (1) ◽

Author(s):

Sayeda M. Abdo ◽

Guzine I. El Diwani ◽

Kamel M. El-Khatib ◽

Sanaa A. Abo El-Enin ◽

Mohammed I. El-Galad ◽

...

Keyword(s):

Active Compound ◽

Municipal Wastewater ◽

Scenedesmus Obliquus ◽

Cetane Number ◽

Treatment Plant ◽

Acid Methyl Ester ◽

Biodiesel Production ◽

High Rate ◽

Total Phenolic ◽

Microscopical Examination

Abstract Background Microalgae cells can be identified as a potential source for new and renewable energy. The economic investigation for biodiesel and bio-active compound production from the microalgae community (Bloom), which are collected from the high rate algal pond (HRAP) constructed to treat municipal wastewater at Zenin wastewater treatment plant, Giza, was the main target of study. Results The microscopical examination showed that Scenedesmus obliquus is the dominant species. The total carotenoids were extracted using jojoba oil and determined by high-performance liquid chromatography (HPLC) to reach 81.44 μg/g. The biodiesel production through acid transesterification reaction recorded 70.6% of fatty acid methyl ester content with high cetane number (44) and low acid value. Such results prove that the obtained biodiesel has better ignition quality. The total phenolic and flavonoid compounds have been derived from the remaining biomass to give 5.36 ± 0.03 and 1.50 ± 0.19 mg/g respectively. Finally, total proteins and carbohydrates content in algal cells were recorded 54.3 and 1.5 mg/g successively Conclusion The preliminary economic evaluation showed that the production of biodiesel and carotenoids from the microalgae growing in municipal wastewater can be considered, as a techno-economic feasible process.

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