1.

Sekundar-Carotinoide (SC) sind Carotinoide, die in Organismen oder in ihren Organen meist gegen Ende ihrer Entwicklungsperioden an Stelle oder in Erganzung der primaren, normalerweise vorhandenen Carotinoide synthetisiert werden.




2.

Bei den SC handelt es sich bevorzugt um Oxoderivate des β-Carotins: 3,3′-Dioxi-4,4′-dioxo-β-carotin (Astaxanthin); 3-Oxi-4,4′-dioxo-β-carotin; 4,4′-Dioxo-β-carotin (Canthaxanthin); 3-Oxi-4-oxo-β-carotin; 4-Oxo-β-carotin (Echinenon). Die Oxi-Polyene sind im nativen Zustand verestert.




3.

164 Stamme aus der Klasse derChlorophyta (148 Chlorococcale, 15 Volvocale, 1 Siphonale) wurden auf ihre Fahigkeit untersucht, SC zu bilden (vgl. Tab. 1)




4.

Die SC werden vermutlich innerhalb der Chloroplasten synthetisiert. Synchron dazu verlauft die Bildung fetter Ole. Die SC difundieren in die Fettvacuolen und werden verestert.




5.

Die Algen haufen SC bei vermindertem Stoffwechsel, insbesondere bei N-Mangel an. Diese Fahigkeit ist artspezifisch und unabhangig von den Kulturbedingungen (z.B. von der N-Quelle). N-Mangelalgen bauen bei Zusatz von N die SC wieder ab und die primaren Pigmente erneut auf.




6.

Licht beeinflust die Biogenese der SC nur indirekt uber die Steigerung des Stoffwechsels.




7.

Zusatze von Kohlenhydraten, Acetat, Pyruvat und Succinat erhohen die Konzentration an SC nicht. Der Einflus dieser Substanzen auf die SC-Bildung ist indirekt. Sie steigern das Wachstum, so das die N-Quelle schneller verbraucht wird. Infolgedessen setzt die Synthese der SC fruher als in Normalkulturen ein.

Sekundär-Carotinoide in Grünalgen

Sekundr-Carotinoide in Grnalgen: I. Chemie, Vorkommen und Faktoren, welche die Bildung dieser Polyene beeinflussen

The endosymbiotic origin of plastids was a launching point for eukaryotic evolution. The autotrophic abilities bestowed by plastids are responsible for much of the eukaryotic diversity we observe today. But despite its many advantages, photosynthesis has been lost numerous times and in disparate lineages throughout eukaryote evolution. For example, among green algae, several groups have lost photosynthesis independently and in response to different selective pressures; these include the parasitic/pathogenic trebouxiophyte genera Helicosporidium and Prototheca, and the free-living chlamydomonadalean genera Polytomella and Polytoma. Here, we examine the published data on colorless green algae and argue that investigations into the different evolutionary routes leading to their current nonphotosynthetic lifestyles provide exceptional opportunities to understand the ecological and genomic factors involved in the loss of photosynthesis.

https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/nph.13279

When the lights go out: the evolutionary fate of free‐living colorless green algae

Pigmentation and carotenoid metabolism of the marine isopod Idotea metallica

Each carotenoid is designated by a prefix number in bold type, which is used for reference throughout this book. Above the structural formula, the commonly used trivial name and additional designations are given, with obsolete or erroneous names in double quotation marks. Shown last is the semi-systematic name (cf. nomenclature rules in the Appendix of this monograph). Uncertainty in a structural formula is indicated by a question mark and uncertain natural occurrence by the term ‘natural?’. A query after a trivial name leaves open the question whether the structural formula shown is correct for the pigment concerned.

Lists of Natural Carotenoids

The he te ro t roph ie phytof lage l la te Polytoma uvella is considered a descenden~ of t he chlorophyl lous pho tosyn the t i c Chlamydomonas of the class Chlorophyceae (FlZlTSCI~ 1948). I t s mo*ile s tage has a yel low-orange colour, while i ts res t ing s tage is charac te r ized b y the p roduc t ion of cysts t h a t are da rke r r ed (PI~I~GSI~EIH 1926; STlZ]~HLOW 1929). A s t u d y of the carotenoids and o ther l ipids of P. uvella was deemed in te res t ing because the carotenoids of the f lagellates have scarcely been inves t iga t ed (Goo~)wI~ 1952). The compara t i ve b iochemis t ry of t he caro tenoids of the phy~oflagellates m a y con t r ibu te to establistf ing phylogenet ic re la t ionships (GooI)wlN 1952; LwoFF 1951; HUTXEI~ and PRo. VASOLI 1951; ST~AI~ 1944).

The carotenoids of Polytoma uvella.

1)

Polytoma uvella (strain 1) grows excellently on the following basic medium: sodium acetate, 0.2%; asparagine, 0.2%; K2HPO4, 0.02%; MgSO4.7H2O, 0.01%; Na2CO3, 0.02%; pH=7.5 (in distilled water). Caramel, CaCl2, FeCl3 or other additional trace metals are not required.




2)

Replacement of asparagine by glycine resulted in very poor growth. Addition of thiamin, vitamin B12 or trace elements did not improve the glycine medium. It is suggested thatPolytoma uvella needs small amounts of a Krebs cycle intermediate for good growth.

Some growth experiments withPolytoma uvella on synthetic media

1)

The steroid mixture fromPolytoma uvella, precipitated with digitonine, was investigated spectrophotometrically (ultraviolet and infrared) and by means of paper chromatography at different temperatures.




2)

A provitamin-D-like substance, similar but not identical with ergosterol and probably also not identical with 7-dehydrocholesterol was present in a varying percentage (15–55%) of the total steroids.




3)

The total fatty acids amounted to 11% of the dry weight. Saturated acids amounted to 23–33%, monoenoic acid to about 30%, dianoic acid to 22–25%, trienoic acid to 10–12% and tetraenoic acid to 11–14% of the fatty acid mixture.

J. Links

Papers

The carotenoids of Polytoma uvella.

Some growth experiments withPolytoma uvella on synthetic media

The steroids and higher fatty acids of the phytoflagellatePolytoma uvella