Population studies and carrageenan properties of Chondracanthus teedei var. lusitanicus (Gigartinaceae, Rhodophyta)

Abstract

Features of an intertidal population of Chondracanthus teedei var. lusitanicus, which occurs in sandy basins on rocky shores of part of the Portuguese coast (Buarcos, Figueira da Foz), were studied over one year. Biomass and plant size showed a small increase in early spring (April), a marked increase in early summer (June/July) and were at a minimum in late summer. There was generally more tetrasporophytes (4-32.5%) than female gametophytes (3-29%), which contrasts with other geographical regions where C. teedei populations have been studied, such as Brazil and France. However, non-fructified thalli predominated throughout the year. Phycocolloid extracts were compared for the various stages using spectroscopic methods (FTIR, FT-Raman, 1 Hand 13 C-NMR). These showed a hybrid carrageenan belonging to the lambda family in the tetrasporophyte and a hybrid kappa-iota-mu-nu carrageenan in the female gametophyte and non-fructified thalli. The average phycocolloid content was 34.9% dry weight, with a maximum of 43.6% in July. The combination of high available biomass and phycocolloid content makes this species a potentially important source of kappa/iota hybrid carrageenan in Portugal additional to the traditionally harvested carrageenophytes.

Portuguese carrageenophytes: Carrageenan composition and geographic distribution of eight species (Gigartinales, Rhodophyta)

“…teedei is an alga with isomorphic, tri-phasic life-cycle (Guiry, West, Kim & Masuda, 1984;Pereira and Mesquita, 2004). Its tetrasporic thalli were present in all of the sites sampled (see Fig.…”

“…In the laboratory, carrageenophytes were sorted into their different life-cycle phases, using a stereomicroscope, and then rinsed in distilled water to eliminate debris and salt. The plants were dried, in a ventilated oven, to constant weight at 60 • C, according to the process described by Pereira, Sousa, Coelho, Amado, and Ribeiro-Claro (2003) and Pereira and Mesquita (2004). The results were presented as average ± standard error (with n = number of samples used in study).…”

“…The carrageenan was precipitated by adding the warm solution to twice its volume of 96% ethanol. Coagula were dried for 48 h at 60 • C, and then weighed to determine the carrageenan content (% of dry weight) (Pereira & Mesquita, 2004). Each sample was extracted in quadruplicate for carrageenan yield determinations.…”

“…The process of moderate alkaline extraction is used, at the industrial level, when cold soluble carrageenans and/or with the ability to increase the viscosity are required (Falshaw et al, 2003). The method of alkaline extraction used in this study Pereira & Mesquita, 2004) allowed for extraction of carrageenan types with a low degree of degradation (Ciancia, Noseda, Matulewicz & Cerezo, 1993) and thus with higher molecular weights. It has been confirmed that the carrageenan extraction of kappa family carrageenans, even under "soft" (low pressures and temperatures), promotes the cyclization of carrageenan precursors.…”

Alterations in architecture and metabolism induced by ultraviolet radiation-B in the carragenophyte Chondracanthus teedei (Rhodophyta, Gigartinales)

“…As a source of kappa carrageenan extraction throughout the world, it has achieved significant economic importance. These sulphated polysaccharides present in the cell walls of members of the Gigartinales have been used extensively as gels and thickeners in food and industrial preparations (Pereira and Mesquita 2004).…”