Faculty Opinions recommendation of Interactions between nitrogen form, loading rate, and light intensity on Microcystis and Planktothrix growth and microcystin production.

2018 ◽  
Author(s):  
Hans Paerl
Keyword(s):  
Light Intensity ◽  
Loading Rate ◽  
Nitrogen Form ◽  
Microcystin Production

Interactions between nitrogen form, loading rate, and light intensity on Microcystis and Planktothrix growth and microcystin production

Harmful Algae ◽  
2018 ◽  
Vol 73 ◽  
pp. 84-97 ◽  
Author(s):  
Justin D. Chaffin ◽  
Timothy W. Davis ◽  
Derek J. Smith ◽  
Mikayla M. Baer ◽  
Gregory J. Dick
Keyword(s):  
Light Intensity ◽  
Loading Rate ◽  
Nitrogen Form ◽  
Microcystin Production

scholarly journals Nitrogen form, concentration, and micronutrient availability affect microcystin production in cyanobacterial blooms

Harmful Algae ◽  
2021 ◽  
Vol 103 ◽  
pp. 102002
Author(s):  
Nicole D. Wagner ◽  
Emily Quach ◽  
Seth Buscho ◽  
Ashely Ricciardelli ◽  
Anupama Kannan ◽  
...  
Keyword(s):  
Cyanobacterial Blooms ◽  
Nitrogen Form ◽  
Microcystin Production ◽  
Micronutrient Availability

scholarly journals The Microcystin Composition of the Cyanobacterium Planktothrix agardhii Changes toward a More Toxic Variant with Increasing Light Intensity

2005 ◽  
Vol 71 (9) ◽  
pp. 5177-5181 ◽  
Author(s):  
Linda Tonk ◽  
Petra M. Visser ◽  
Guntram Christiansen ◽  
Elke Dittmann ◽  
Eveline O. F. M. Snelder ◽  
...  
Keyword(s):  
Light Intensity ◽  
Production Rate ◽  
High Light ◽  
Constant Independent ◽  
Mrna Transcript ◽  
Eutrophic Lakes ◽  
Planktothrix Agardhii ◽  
Cellular Content ◽  
Light Intensities ◽  
Microcystin Production

ABSTRACT The cyanobacterium Planktothrix agardhii, which is dominant in many shallow eutrophic lakes, can produce hepatotoxic microcystins. Currently, more than 70 different microcystin variants have been described, which differ in toxicity. In this study, the effect of photon irradiance on the production of different microcystin variants by P. agardhii was investigated using light-limited turbidostats. Both the amount of the mRNA transcript of the mcyA gene and the total microcystin production rate increased with photon irradiance up to 60 μmol m−2 s−1, but they started to decrease with irradiance greater than 100 μmol m−2 s−1. The cellular content of total microcystin remained constant, independent of the irradiance. However, of the two main microcystin variants detected in P. agardhii, the microcystin-DeRR content decreased twofold with increased photon irradiance, whereas the microcystin-DeLR content increased threefold. Since microcystin-DeLR is considerably more toxic than microcystin-DeRR, this implies that P. agardhii becomes more toxic at high light intensities.

Fine structure of the retina of the giant scallop, Placopecten magellanicus

1984 ◽  
Vol 42 ◽  
pp. 312-313
Author(s):  
C.V.L. Powell
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Light Intensity ◽  
Scanning Electron Microscope ◽  
Eye Development ◽  
Preliminary Observation ◽  
Columnar Epithelium ◽  
Placopecten Magellanicus ◽  
Environmental Light ◽  
Scanning Electron

The overall fine structure of the eye in Placopecten is similar to that of other scallops. The optic tentacle consists of an outer columnar epithelium which is modified into a pigmented iris and a cornea (Fig. 1). This capsule encloses the cellular lens, retina, reflecting argentea and the pigmented tapetum. The retina is divided into two parts (Fig. 2). The distal retina functions in the detection of movement and the proximal retina monitors environmental light intensity. The purpose of the present study is to describe the ultrastructure of the retina as a preliminary observation on eye development. This is also the first known presentation of scanning electron microscope studies of the eye of the scallop.

Effect of light intensity on the ultrastructure of the filamentous cyanobacterium, Anabaena variabilis

1988 ◽  
Vol 46 ◽  
pp. 300-301
Author(s):  
C. S. Bricker ◽  
S. R. Barnum ◽  
B. Huang ◽  
J. G. Jaworskl
Keyword(s):  
Fatty Acid ◽  
Light Intensity ◽  
Acid Content ◽  
Fatty Acid Content ◽  
Anabaena Variabilis ◽  
Chloroplast Envelope ◽  
Major Constituent ◽  
Filamentous Cyanobacterium ◽  
Photosynthetic Membrane ◽  
Effect Of Light

Cyanobacteria are Gram negative prokaryotes that are capable of oxygenic photosynthesis. Although there are many similarities between eukaryotes and cyanobacteria in electron transfer and phosphorylation during photosynthesis, there are two features of the photosynthetic apparatus in cyanobacteria which distinguishes them from plants. Cyanobacteria contain phycobiliproteins organized in phycobilisomes on the surface of photosynthetic membrane. Another difference is in the organization of the photosynthetic membranes. Instead of stacked thylakolds within a chloroplast envelope membrane, as seen In eukaryotes, IntracytopIasmlc membranes generally are arranged in three to six concentric layers. Environmental factors such as temperature, nutrition and light fluency can significantly affect the physiology and morphology of cells. The effect of light Intensity shifts on the ultrastructure of Internal membrane in Anabaena variabilis grown under controlled environmental conditions was examined. Since a major constituent of cyanobacterial thylakolds are lipids, the fatty acid content also was measured and correlated with uItrastructural changes. The regulation of fatty acid synthesis in cyanobacteria ultimately can be studied if the fatty acid content can be manipulated.

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