In‐situ monitoring of chlorophyll a fluorescence in Nannochloropsis oceanica cultures to assess photochemical changes and the onset of lipid accumulation during nitrogen deprivation

2021 ◽  
Author(s):  
Mariana Carneiro ◽  
Graziella Chini Zittelli ◽  
Bernardo Cicchi ◽  
Elefterios Touloupakis ◽  
Cecilia Faraloni ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Lipid Accumulation ◽  
In Situ Monitoring ◽  
Nitrogen Deprivation ◽  
Nannochloropsis Oceanica

scholarly journals Online monitoring of chlorophyll a fluorescence in Nannochloropsis oceanica to assess photochemical changes and the onset of lipid accumulation during nitrogen deprivation

2021 ◽  
Author(s):  
Mariana Carneiro ◽  
Graziella Chini Zittelli ◽  
Bernardo Cicchi ◽  
Elefterios Touloupakis ◽  
Cecilia Faraloni ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Chlorophyll A ◽  
Lipid Content ◽  
Chlorophyll A Fluorescence ◽  
Biochemical Parameters ◽  
Total Lipid Content ◽  
Effective Quantum Yield ◽  
Nitrogen Deprivation ◽  
Nannochloropsis Oceanica ◽  
Fluorescence Measurements

In this work, we applied online chlorophyll a fluorescence measurements to monitor the changes in the photochemical parameters both in nitrate-deplete and nitrate-replete cultures of Nannochloropsis oceanica, in addition to biochemical parameters such as growth, lipid, fatty acid, and pigment contents. Under nitrate-replete conditions, growth was promoted along with pigment content, while total lipid content and fatty acid saturation level diminished. Under nitrate-deplete conditions, cultures showed an increased de-epoxidation state of the xanthophyll cycle pigments. Fast transients revealed a poor processing efficiency for electron transfer beyond QA, which was in line with the low electron transport rate due to nitrate depletion. Lipid content and the de-epoxidation state were the first biochemical parameters triggered by the change in nutrient status, which coincided with a 20% drop in the online effective quantum yield of PSII (ΔF/Fm’), and a raise in the Vj measurements. A good correlation was found between the changes in ΔF/Fm’ and lipid content (r=-0.96, p<0.01). The results confirm the reliability and applicability of online fluorescence measurements to monitor lipid induction in N. oceanica.

In situ determination of sun‐induced chlorophyll a fluorescence quantum yield in the North China Sea

2007 ◽  
Vol 29 (3) ◽  
pp. 851-865 ◽  
Author(s):  
X. Xing ◽  
D. Zhao ◽  
Y. Liu ◽  
J. Yang ◽  
L. Wang
Keyword(s):  
Quantum Yield ◽  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Fluorescence Quantum Yield ◽  
North China ◽  
China Sea ◽  
The North

Modified in situ antimicrobial susceptibility testing method based on cyanobacteria chlorophyll a fluorescence

2016 ◽  
Vol 121 ◽  
pp. 1-4 ◽  
Author(s):  
Nikolaos S. Heliopoulos ◽  
Angeliki Galeou ◽  
Sergios K. Papageorgiou ◽  
Evangelos P. Favvas ◽  
Fotios K. Katsaros ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Antimicrobial Susceptibility ◽  
Chlorophyll A Fluorescence ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Testing Method

scholarly journals Reliability of estimating chlorophyll a concentrations in Antarctic waters by measurement of in situ chlorophyll a fluorescence

2000 ◽  
Vol 196 ◽  
pp. 103-110 ◽  
Author(s):  
O Holm-Hansen ◽  
AF Amos ◽  
CD Hewes
Keyword(s):  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Antarctic Waters

A new method for the accurate in situ monitoring of chlorophyll a fluorescence in lichens and bryophytes

2001 ◽  
Vol 33 (5) ◽  
pp. 443-452 ◽  
Author(s):  
Mark Schlensog ◽  
Burkhard Schroeter
Keyword(s):  
Chlorophyll A ◽  
Carbon Balance ◽  
Fluorescence Probe ◽  
Pulse Amplitude ◽  
In Situ Monitoring ◽  
New Method ◽  
Fixed Position ◽  
Poikilohydric Organisms ◽  
Thallus Surface

AbstractA new method has been developed to measure chlorophyll a fluorescence of bryophytes and lichens in situ in the field. Specially designed aluminium stands fixed to rocks or other suitable substrata allow several cryptogam thalli to be measured sequentially with only one pulse amplitude modulated (PAM) chlorophyll a fluorescence analyser. The stands guarantee a fixed position for the fluorescence probe in relation to the thallus surface and also provide the possibility to darken the thalli so that both the apparent and the potential quantumefficiency of PSII (▵F/Fm′ and Fv/Fm) can be measured. A detailed analysis of chlorophyll a quenching parameters (qP, qN, NPQ) can also be performed with only minimal changes in the environmental conditions. The method allows easy detection of periods of metabolic activity and inactivity of the poikilohydric organisms. In combination with gas–exchange and microclimatic measurements the carbon balance also can be calculated. The method is described in detail and examples of its application in the field are presented

The piezoelectric implant: its applications to the in situ monitoring of materials

2001 ◽  
Vol 89 ◽  
pp. 24-26
Author(s):  
Y. Jayet ◽  
J.-C. Baboux
Keyword(s):  
In Situ Monitoring

Fetal pulse oximeter for in situ monitoring during labour and birth

2008 ◽  
Vol 52 (1-2) ◽  
pp. 85
Author(s):  
Ákos Becker ◽  
Gábor Harsányi
Keyword(s):  
Pulse Oximeter ◽  
In Situ Monitoring
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