scholarly journals CONTINUOUS CULTURE OF MARINE DIATOMS UNDER SILICATE LIMITATION. II. EFFECT OF LIGHT INTENSITY ON GROWTH AND NUTRIENT UPTAKE OF SKELETONEMA COSTATUM 1 ,2

1976 ◽  
Vol 12 (3) ◽  
pp. 291-300 ◽  
Author(s):  
Curtiss O. Davis
1984 ◽  
Vol 41 (3) ◽  
pp. 540-544 ◽  
Author(s):  
J. S. Parslow ◽  
P. J. Harrison ◽  
P. A. Thompson

Our new technique allows the decline in ambient ammonium concentration to be followed continuously during phytoplankton uptake experiments. A self-cleaning, in-line filter permits the continuous separation of cells from the medium for nutrient determination by an autoanalyzer. The technique works well with laboratory cultures of the marine diatoms Thalassiosira pseudonana and Skeletonema costatum. Changes in uptake rate on time scales of 1 min or longer can be resolved, the resolution being limited by the response characteristics of the autoanalyzer.


1963 ◽  
Vol 14 (2) ◽  
pp. 148 ◽  
Author(s):  
GF Humphrey

Gymnodinium, Nitzschia closterium, and Skeletonema costatum were grown in the presence of bacteria, and N. closterium in the absence of bacteria, for 7 weeks. Each week samples were analysed by the Richards-Thompson method for chlorophyll a and c. Maximum cell numbers were reached in 1-3 weeks. Gymnodinium grew better at 680 f.c. than at 420 f.c. but the reverse was true of Nitzschia and Skeletonema. The chlorophyll content of the Gymnodinium cultures was similar at each light intensity but Nitzschia gave more chlorophyll at 420 f.c. With Skeletonema there was no consistent effect of light. During the initial growth phase, Gymnodinium contained 0.33-0.87 �g chlorophyll a and 0.56-1.88 pg chlorophyll c per million cells. The corresponding figures for Skeletonema were 0.03-0.06 and 0.03-0.08, and for Nitzschia 0.13-1.08 and 0.11-0.87. The ratio of c to a varied from 1.30 to 1.84 for Gymnodinium, 0.69 to 1 .61 for Skeletonema, and 0.44 to 2.21 for Nitzschia. These ratios are all less than the maximum (3.3) found for natural populations of phytoplankton from the Coral and Tasman Seas. There was no evidence in the culture experiments that chlorophyll c breaks down more slowly than a and thus accumulates in old populations.


Author(s):  
D. Setyaningrum ◽  
M.T.S Budiastuti ◽  
B. Pujiasmanto ◽  
D. Purnomo ◽  
Supriyono Supriyono

This research investigated the effect of light intensity and biofertilizer on the yield, which includes the production of indigo compounds and plant nutrient uptake. The study used a randomized complete block design with a split plot design with 4 levels of light intensity as the main plots and 4 levels of biofertilizer as a sub plots with 3 replications. The combination of light intensity and biofertilizer affects fresh weight, biomass and tissue nitrogen. The highest fresh weight and biomass was found at 100% light intensity with double inoculation of mycorrhizae and rhizobium. Whereas the highest tissue nitrogen was at 10% light intensity with double inoculation of mycorrhizae and rhizobium. The production of indigo affected by light intensity, ie at 10% light intensity indicates the highest indigo. Mycorrhizae and rhizobium have a synergistic relationship as biofertilizer in increasing plant yields and nutrient uptakes in 100% light intensity.


Author(s):  
C. S. Bricker ◽  
S. R. Barnum ◽  
B. Huang ◽  
J. G. Jaworskl

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.


2019 ◽  
Vol 64 (11) ◽  
pp. 1007-1014
Author(s):  
Tong XU ◽  
◽  
Jia-Hui ZHANG ◽  
Zhao-Ying LIU ◽  
Xuan LI ◽  
...  

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