AUTHOR=Pasqualetti Cesar B. , Carvalho Maria Angela M. , Mansilla Andres , Avila Marcela , Colepicolo Pio , Yokoya Nair S. 

TITLE=Variations on primary metabolites of the carrageenan-producing red algae Sarcopeltis skottsbergii from Chile and Sarcopeltis antarctica from Antarctic Peninsula

JOURNAL=Frontiers in Marine Science

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2023.1151332

DOI=10.3389/fmars.2023.1151332

ISSN=2296-7745

ABSTRACT=<p>Several studies reported that gametophytes and tetrasporophytes of Gigartinaceae produce different carrageenan types, as observed in <italic>Sarcopeltis</italic> species although they have isomorphic haploid and diploid phases. Cystocarpic and non-fertile plants of <italic>Sarcopeltis</italic> (ex <italic>Gigartina</italic>) <italic>skottsbergii</italic> produced kappa-carrageenans, while tetrasporophytes produced lambda-carrageenans, and yields were higher in cystocarpic and sterile specimens than in tetrasporophytes. However, comparison on the other primary metabolites among different life history phases still needed to be investigated. Then, we tested the hypothesis if the variation on primary metabolites (pigments, proteins and carbohydrates) are related to the life history phases of <italic>Sarcopeltis antarctica</italic> and <italic>Sarcopeltis skottsbergii</italic>, and/or are influenced by abiotic factors. Primary metabolites of <italic>S. antarctica</italic> varied according to the life-history phases: non-fertile specimens presented higher phycobiliprotein concentrations, tetrasporophytes presented higher chlorophyll <italic>a</italic> concentrations, and cystocarpic specimens presented higher concentrations of proteins, polysaccharides and floridean starch. However, primary metabolites of <italic>S. skottsbergii</italic> varied in response to some abiotic factors (nutrients, temperature and salinity), since principal component analysis evidenced two groups; one was related by the higher nitrate and phosphate concentrations, and the other was related to the higher temperatures and lower salinities. Concentrations of floridean starch, low molecular weight carbohydrates, and polysaccharides are higher in <italic>S. antarctica</italic> than in <italic>S. skottsbergii</italic>, which could be related to the protective role of these compounds against salinity variation and low temperatures faced in the Antarctic extreme environments.</p>