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In vivo estimation of pigment composition and optical absorption cross-section by spectroradiometry in four aquatic photosynthetic micro-organisms

Paper ID Volume ID Publish Year Pages File Format Full-Text
30191 44463 2013 10 PDF Available
Title
In vivo estimation of pigment composition and optical absorption cross-section by spectroradiometry in four aquatic photosynthetic micro-organisms
Abstract

•In vivo estimation of the pigment absorption bands and the optical absorption cross-section, a∗.•Four photosynthetic micro-organisms cultivated at two PAR levels were analyzed.•A new methodology was proposed: spectroradiometry measuring reflectances.•Some absorption bands were ubiquous, others were taxonomically specific and/or photo-physiological dependent.•A double peak feature at 671 and 683 nm, supposed to be caused by PSII and PSI, was detected.

The objective of the present study was to estimate in vivo pigment composition and to retrieve absorption cross-section values, a∗, of photosynthetic micro-organisms using a non-invasive technique of reflectance spectrometry. To test the methodology, organisms from different taxonomical groups and different pigment composition were used (Spirulina platensis a Cyanophyta, Porphyridium cruentum a Rhodophyta, Dunaliella tertiolecta a Chlorophyta and Entomoneis paludosa a Bacillariophyta) and photoacclimated to two different irradiance levels: 25 μmol photon m−2 s−1 (Low Light, LL) and 500 μmol photon m−2 s−1 (High Light, HL). Second derivative spectra from reflectance were used to identify pigment in vivo absorption bands that were linked to specific pigments detected by high performance liquid chromatography. Whereas some absorption bands such as those induced by Chlorophyll (Chl) a (416, 440, 625 and around 675 nm) were ubiquous, others were taxonomically specific (e.g. 636 nm for Chl c in E. paludosa) and/or photo-physiological dependent (e.g. 489 nm for zeaxanthin in the HL-acclimated S. platensis). The optical absorption cross-section, a∗, was retrieved from reflectance data using a radiative transfer model previously developed for microphytobenthos. Despite the cellular Chl a decrease observed from LL to HL (up to 88% for S. platensis), the a∗ increased, except for P. cruentum. This was attributed to a ‘package effect’ and to a greater absorption by photoprotective carotenoids that did not contribute to the energy transfer to the core Chl a.

Keywords
Microalgae; Cyanobacteria; In vivo absorption bands; Reflectance; Pigments; Absorption cross-section
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In vivo estimation of pigment composition and optical absorption cross-section by spectroradiometry in four aquatic photosynthetic micro-organisms
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Photochemistry and Photobiology B: Biology - Volume 129, 5 December 2013, Pages 115–124
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us