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Titolo:
Carotenoid composition of terrestrial Cyanobacteria: response to natural light conditions in open rock habitats in Venezuela
Autore:
Lakatos, M; Bilger, W; Budel, B;
Indirizzi:
Univ Kaiserslautern, Dept Bot, D-67653 Kaiserslautern, Germany Univ Kaiserslautern Kaiserslautern Germany D-67653 iserslautern, Germany Univ Kiel, Dept Bot, D-24098 Kiel, Germany Univ Kiel Kiel Germany D-24098 niv Kiel, Dept Bot, D-24098 Kiel, Germany
Titolo Testata:
EUROPEAN JOURNAL OF PHYCOLOGY
fascicolo: 4, volume: 36, anno: 2001,
pagine: 367 - 375
SICI:
0967-0262(200111)36:4<367:CCOTCR>2.0.ZU;2-E
Fonte:
ISI
Lingua:
ENG
Soggetto:
GREEN-ALGAL LICHENS; ZEAXANTHIN; PIGMENT; SCYTONEMIN; PHOTOPROTECTION; SYNECHOCOCCUS; OSCILLATORIA; APPARATUS; PCC-6803; FIELD;
Keywords:
beta-carotene; canthaxanthin; carotenoid; cyanobacteria; inselberg; light acclimation; myxoxanthophyll; table mountain; Venezuela;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
47
Recensione:
Indirizzi per estratti:
Indirizzo: Lakatos, M Univ Kaiserslautern, Dept Bot, POB 3049, D-67653 Kaiserslautern, Germany Univ Kaiserslautern POB 3049 Kaiserslautern Germany D-67653 ny
Citazione:
M. Lakatos et al., "Carotenoid composition of terrestrial Cyanobacteria: response to natural light conditions in open rock habitats in Venezuela", EUR J PHYC, 36(4), 2001, pp. 367-375

Abstract

Carotenoid contents of terrestrial cyanobacteria sampled from rock surfaces with different exposure to sunlight were studied in the Guyana-shield region of Venezuela. At the collecting locations of two table mountains Roraima-tepui (2700 m). Auyan-tepui (2000 m) and an inselberg near Puerto Ayacucho (80 m), the most frequent species were Stigonema ocellatum, Stigonema hormoides and Scytonema crassum, respectively. Usually, these species were associated with the unicellular cyanobacterium Gloeocapsa sanguinea. Their carotenoid and chlorophyll a contents were determined by high-performance liquid chromatography. In general, carotenoids consisted almost equally of myxolglycosides and of beta -carotene derivatives, such as beta -carotene, echinenone and canthaxanthin, On a chlorophyll a basis, myxolglycoside content increased in full exposure to solar irradiation. The relative proportions of the different beta -carotene derivatives appeared to be even more strongly influenced by irradiance, Whereas their total amount was increased at full exposure, the content of beta -carotene decreased and that of canthaxanthin increased. Maximal ratios of canthaxanthin/beta -carotene of around 5 were observed in the most sun-exposed samples. We conclude that acclimation of the carotenoid content to irradiance, especially the adjustment or the ratio canthaxanthin/beta -carotene, is a response found in many different terrestrial cyanobacterial species, However. when a natural population was artificially shaded for 6 days, short-term acclimation in pigment content was not detected, The results support a photoprotective function of canthaxanthin in terrestrial cyanobacteria under natural environmental conditions.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/12/20 alle ore 13:04:39