CARRAGEENANS BIOSYNTHESIZED BY CARPOSPOROPHYTES OF RED SEAWEEDS GIGARTINA SKOTTSBERGII (GIGARTINACEAE) AND GYMNOGONGRUS TORULOSUS (PHYLLOPHORACEAE)¹

Abstract

Carrageenans biosynthesized by gametophytic and tetrasporic plants of seaweeds belonging to the Gigartinaceae and Phyllophoraceae are different: gametophytes produce carrageenans of the kappa family, whereas lambda‐carrageenans are extracted from tetrasporophytes. For Gigartina skottsbergii Setchell and Gardner and Gymnogongrus torulosus Hooker et Harvey, mature cystocarps were isolated and carrageenans were extracted. Structural determination by methylation analysis, Fourier transform infrared spectroscopy, and 13C‐NMR spectroscopy showed that they were kappa/iota‐carrageenans. For the extract obtained from cystocarps of Gigartina skottsbergii with water at room temperature, the ratio kappa:iota was 1:0.30 and at 90° C was 1:0.43; significant amounts of precursors were also present. The extract obtained from cystocarps of Gymnogongrus torulosus at 90° C showed prevalence of iota‐carrageenans (ratio kappa:iota 1:1.21). These extracts are similar to the polysaccharides produced by gametophytes of these seaweeds. For Gigartina skottsbergii, it was possible to separate the pericarpic tissue from the carposporophyte. Thus, they were extracted separately, and the carrageenans isolated were studied as described before, obtaining similar conclusions. These results clearly show that whereas the carposporophytes are located inside the cystocarp, they produce carrageenans of the kappa family despite of being diploid cells.

FOURIER TRANSFORM INFRARED MICROSPECTROSCOPY AS A TOOL TO IDENTIFY MACROALGAL PROPAGULES1

“…Specifically, the aims of this study were, using FT‐IR microspectroscopy, to (1) corroborate evidence from previous studies (McCandless et al. 1983, Estevez et al. 2002) of the presence of κ‐carrageenan in gametophytes and carposporophytes, and λ‐carrageenan in tetrasporophytes of C. verrucosus ; (2) assess whether individual carpospores and tetraspores of C. verrucosus could be reliably discriminated based on FT‐IR microspectroscopy; and (3) assess the effect of different types of data pretreatment on the accuracy of classification of spore types (Heraud et al.…”

“…They also implied that this relationship should hold for diploid carpospores and haploid tetraspores (Gordon‐Mills and McCandless 1975). However, Estevez et al. (2002), using FT‐IR spectroscopy and 13 C‐nuclear magnetic resonance ( 13 C‐NMR) spectroscopy on carposporophytes of Gigartina skottsbergii (Gigartinaceae) separated from the gametophytic pericarp tissue, clearly demonstrated that the diploid carposporophytes contained κ‐ and ι‐carrageenans like the haploid gametophytes.…”

“…We can find no reports of studies that have assessed the carrageenan content of spores for species within the Gigartinaceae or Phyllophoraceae, but based on evidence of cell‐wall formation during coalescence (Santelices et al. 1999), Estevez et al. (2002) suggested that carpospores should contain κ‐ and ι‐carrageenans and produce λ‐carrageenan after settlement during outer cell‐wall formation.…”

Metais Pesados em Macroalgas Marinhas na Costa Norte do Estado do Rio de Janeiro, Brasil.

“…As concentrações de Cr (3,0µg.g -1 ), Cu (4,1µg.g -1 ), Fe (1087µg.g -1 ), Mn (243,5µg.g -1 ) e Zn (32µg.g -1 ) em Gymnogongrus sp foram em média, maiores que em Ulva fasciata (0,9µg.g -1 ; 2,9µg.g -1 ; 394µg.g -1 ; 9,9µg.g -1 ; 6,4µg.g -1 respectivamente para Cr, Cu, Fe, Mn e Zn). Segundo Estevez et al (2002) algas vermelhas, como as do gênero Gymnogongrus, possuem grupos polissacarídicos, como as carragenanas, ligados à parede celular do vegetal. Wahbeh (1985) cita que estes compostos possuem elevada afinidade por elementos metálicos em função de suas cargas e pela estabilidade de suas ligações com metais pesados.…”

The structure of κ/ι-hybrid carrageenans II. Coil–helix transition as a function of chain composition

“…The list of studied species includes C. crispus, Gigartina alveata, G. clavifera, G. decipiens, G. pistillata, G. skottsbergii, Gymnogongrus torulosus, S. crispata, S. atropurpurea and several commercial and underutilised species collected from the occidental Portuguese coast. 8,[10][11][12][16][17][18][19][20][21][22][23][24] Although the functional properties in dairy applications have been studied for j/i-hybrids extracted from specific species, no systematic analysis of the j/i-hybrids has been reported. Most of the studies mentioned above started from a certain seaweed species and studied the functional properties of the carrageenans extracted.…”