Minerals and trace elements content and concentration in marine algae vary depending on species morphology and physiology;as well as growing environmental conditions. Despite this variability, accumulation of magnesiu...Minerals and trace elements content and concentration in marine algae vary depending on species morphology and physiology;as well as growing environmental conditions. Despite this variability, accumulation of magnesium, and especially iron, seems to be common in Chlorophyta;while Rhodophyta and Heterokontophyta show higher affinity to manganese. The red agarophyte Alsidium triquetrum was used to analyze the relationship between metal concentration, environmental conditions and growth rate. Specimens grown in situ showed a large variability of Fe, Mn, Mg, and Al, in thallus tissue concentrations. Further, a compelling relationship between the growth rate and the thallus concentration of Mg and Mn, Zn, and Al was detecte. Manganese, unlike the other trace elements analyzed showed a positive linear relationship between growth rate and tissue content during the period of greatest vegetative growth.展开更多
Herbivores can drastically alter the morphology of macroalgae by directly consuming tissue and by inflicting structural wounds. Macroalgae host abundant and diverse epibiont communities, the dynamics of which tend to ...Herbivores can drastically alter the morphology of macroalgae by directly consuming tissue and by inflicting structural wounds. Macroalgae host abundant and diverse epibiont communities, the dynamics of which tend to be mostly unknown in space and time. As the cultivation of macroalgae gains momentum worldwide, it is key to measure how epibionts could affect algal performance. We examined the epibiont community associated with farmed Alsidium triquetrum, a red macroalga with growing pharmacological interest. Measurements were conducted over two independent 60-day periods, one in summer and one in winter. Epibionts showed different patterns of succession in both seasons. Crustaceans, mainly amphipods, showed the highest overall density, with deleterious effects on daily growth rates of A. triquetrum in winter. Adverse effects as a function of epibionts were not detected in summer. A. triquetrum is a perennial alga. However, its performance as a crop in the nearshore can be significantly affected by the epibiont community structure that persists in winter. Amphipods and ascoglossan molluscs were risk factors in the mariculture of this agarophyte. In winter, they can destroy plants when they reach more than five individuals per gram of fresh biomass. Results highlight that commercial farming of A. triquetrum would be successful if grown throughout the summer.展开更多
Recent advances in molecular biology make it possible to sequence not only genes or genomes,but also to understand codon dynamics.For the organelle genes of these organisms,a small set of preferred codons are used for...Recent advances in molecular biology make it possible to sequence not only genes or genomes,but also to understand codon dynamics.For the organelle genes of these organisms,a small set of preferred codons are used for encoding proteins.For the first time,this paper treats the divergence of synonymous codon usage and its bias in the rbcL gene within the Laurencia complex of red algae.We observed that the synonymous codon preference biases in rbcL are large and differ among species.A clear distinction in codon usage between genera is evident:the genera Dasya and Delesseria use a set that fluctuated between 53 and 58 codons.Whereas,in the genera Ceramium,Chondrophycus,Chlamydomonas,Chlorella,Laurencia s.s,Osmundea,and Palisada codon usage indicates a higher restriction fluctuating between 40 to 51 codons.Laurencia complex genera and other representative algae showed a defined composition pattern,with lower percentage values of NNC/G(7-24.9%).Dasya and Delesseria showed a selective pattern tendency because of high percentage values of NNC/G(54-55%).The estimated codon bias parameters were tested to infer systematic relationships and match suitable codons with the NNC/G codon percentages.Cluster analysis based on Codon Usage supports phylogenetic relationships between Chondrophycus,Palisada,Laurencia,Osmundea,and Yuzurua species.展开更多
文摘Minerals and trace elements content and concentration in marine algae vary depending on species morphology and physiology;as well as growing environmental conditions. Despite this variability, accumulation of magnesium, and especially iron, seems to be common in Chlorophyta;while Rhodophyta and Heterokontophyta show higher affinity to manganese. The red agarophyte Alsidium triquetrum was used to analyze the relationship between metal concentration, environmental conditions and growth rate. Specimens grown in situ showed a large variability of Fe, Mn, Mg, and Al, in thallus tissue concentrations. Further, a compelling relationship between the growth rate and the thallus concentration of Mg and Mn, Zn, and Al was detecte. Manganese, unlike the other trace elements analyzed showed a positive linear relationship between growth rate and tissue content during the period of greatest vegetative growth.
文摘Herbivores can drastically alter the morphology of macroalgae by directly consuming tissue and by inflicting structural wounds. Macroalgae host abundant and diverse epibiont communities, the dynamics of which tend to be mostly unknown in space and time. As the cultivation of macroalgae gains momentum worldwide, it is key to measure how epibionts could affect algal performance. We examined the epibiont community associated with farmed Alsidium triquetrum, a red macroalga with growing pharmacological interest. Measurements were conducted over two independent 60-day periods, one in summer and one in winter. Epibionts showed different patterns of succession in both seasons. Crustaceans, mainly amphipods, showed the highest overall density, with deleterious effects on daily growth rates of A. triquetrum in winter. Adverse effects as a function of epibionts were not detected in summer. A. triquetrum is a perennial alga. However, its performance as a crop in the nearshore can be significantly affected by the epibiont community structure that persists in winter. Amphipods and ascoglossan molluscs were risk factors in the mariculture of this agarophyte. In winter, they can destroy plants when they reach more than five individuals per gram of fresh biomass. Results highlight that commercial farming of A. triquetrum would be successful if grown throughout the summer.
基金UAM-I-117“Macroalgas Marinas y Salobres”of the CBS-UAMI Division,and the Ministry of Science and Innovation of the Spanish Government(CGL2010-14881).
文摘Recent advances in molecular biology make it possible to sequence not only genes or genomes,but also to understand codon dynamics.For the organelle genes of these organisms,a small set of preferred codons are used for encoding proteins.For the first time,this paper treats the divergence of synonymous codon usage and its bias in the rbcL gene within the Laurencia complex of red algae.We observed that the synonymous codon preference biases in rbcL are large and differ among species.A clear distinction in codon usage between genera is evident:the genera Dasya and Delesseria use a set that fluctuated between 53 and 58 codons.Whereas,in the genera Ceramium,Chondrophycus,Chlamydomonas,Chlorella,Laurencia s.s,Osmundea,and Palisada codon usage indicates a higher restriction fluctuating between 40 to 51 codons.Laurencia complex genera and other representative algae showed a defined composition pattern,with lower percentage values of NNC/G(7-24.9%).Dasya and Delesseria showed a selective pattern tendency because of high percentage values of NNC/G(54-55%).The estimated codon bias parameters were tested to infer systematic relationships and match suitable codons with the NNC/G codon percentages.Cluster analysis based on Codon Usage supports phylogenetic relationships between Chondrophycus,Palisada,Laurencia,Osmundea,and Yuzurua species.
