Strain Selection in Gracilaria spp. I. Growth, Pigment, and Carbohydrates Characterization of Strains of G. conferta and G. verrucosa (Rhodophyta, Gigartinales)

Levy, Israel; Friedländer, Michael

doi:10.1515/botm.1990.33.4.339

Cited by 32 publications

(15 citation statements)

References 14 publications

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“…All experiments were carried out with strain SGSC-6 (Levy & Fnedlander 1990) of Gracilaria conferta. The algae were precultured in the laboratory at room temperature, artificial light ('cool white', 14 h light: l 0 h dark, 52 pE S-' m-2) and strong aeration.…”

Section: Methodsmentioning

confidence: 99%

A bacterial facultative parasite of Gracilaria conferta

Weinberger¹,

Friedländer²,

Gunkel³

1994

Dis. Aquat. Org.

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Bacterial epiphytes of Gracilaria conferta were quantified. Saprophytic bacteria reached 350 times and agar degraders 25000 times higher numbers g-' algal wet wt on tissues infected with the 'white tips disease', as compared to healthy tissues. A bactenal inducing agent of the 'white tips disease' was detected. Addition of 102 to 103 cells of this isolate rnl-I medium led to increased rates of infection. This effect did not occur if the isolate was autoclaved before addition. The virulent bacteria could always be isolated from infected tissues. It frequently, but not always, infected G. conferta and should be regarded as a facultative parasite. Several factors influenced the disease development. Temperatures above 20°C, in combination with photon flux densities of more than 200 pE m-2 S-', increased the rate of infection. Relatively low amounts (more than 25 pg ml-') of certain organic nutrients (peptone and yeast extract) led to strong manifestations of the disease. Addition of agar did not cause any symptoms, while 5 mg I-' of the antibiotic rifampicin prevented the alga from being infected.

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Section: Methodsmentioning

confidence: 99%

A bacterial facultative parasite of Gracilaria conferta

Weinberger¹,

Friedländer²,

Gunkel³

1994

Dis. Aquat. Org.

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“…Although there are many studies concerning the physiology of the genus, few of them focus on colour strains. Colour mutants have been observed in many species of Gracilaria (Zhang & van der Meer 1988, Levy & Friedlander 1990, van der Meer 1990, most of them are green (van der Meer 1990). Some colour strains occur spontaneously (van der Meer 1990, Costa & Plastino 2001, while others are artificially produced in laboratory (van der Meer 1990 (van der Meer 1981(van der Meer , 1986.…”

Section: Introductionmentioning

confidence: 99%

Growth of red and green strains of the tropical agarophyte Gracilaria cornea J. Agardh (Gracilariales, Rhodophyta) in laboratory

2006

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-(Growth of red and green strains of the tropical agarophyte Gracilaria cornea J. Agardh (Gracilariales, Rhodophyta) in laboratory). Gracilaria cornea J. Agardh is an important agarophyte occurring in the western Atlantic Ocean. Green colour individuals of G. cornea were found in a natural population, growing next to red individuals, which were more common. Due to the importance of colour strains in genetic and intraspecific variability studies, this work aimed to characterize the red and green strains evaluating different nutritional and light conditions. Red and green gametophytes were cultivated at 14:10 light: dark cycle, with alternating aeration periods of 30 min. Two different enriched solutions were tested: von Stosch (VSS) at concentrations reduced to 12.5% and 25%; and Provasoli (PES) at concentrations reduced to 25% and 50%, and 100%. Red and green gametophytes were cultivated at the irradiance of 45 µmol photons m -2 s -1 . In another experiment utilizing PES 100%, two sources of light (Osram 40 W daylight fluorescent tubes and Sylvania Designer 3,500 tubes) were tested at irradiances of 90 and 180 µmol photons m -2 s -1. Growth rates (GR) were evaluated for five weeks. Gametophytes developed few branches and reproductive structures were not induced. Differences were not observed between GR of red and green strains in the conditions tested. GR were higher in VSS 12.5% (8.4% day -1 ) than in 25% (7.1% day -1 ), suggesting an adaptation of the species to low nutrient concentrations. GR were higher at 180 (9.0% day -1 ) than at 90 µmol photons m -2 s -1 (6.3% day -1 ). These results suggest that G. cornea should be cultivated in laboratory at high irradiances and low nutrient concentrations. These data will be useful in future genetic and physiological studies of the species.Key words -agarophyte, colour strain, Gracilaria cornea, growth, light RESUMO -(Crescimento de linhagens de coloração verde e vermelha da agarófita tropical Gracilaria cornea J. Agardh (Gracilariales, Rhodophyta) em laboratório). Gracilaria cornea J. Agardh é uma importante agarófita que ocorre no Oeste do Oceano Atlântico. Indivíduos de coloração verde de G. cornea foram encontrados em uma população natural, próximos a indivíduos de coloração vermelha, mais comuns. Devido à importância de linhagens cromáticas em estudos de genética e variabilidade intraespecífica, o objetivo deste trabalho foi caracterizar as linhagens verde e vermelha avaliando diferentes condições de nutrintes e luz. Gametófitos verdes e vermelhos foram cultivados em fotoperíodo de 14 horas (14L:10E), com períodos alternados de aeração de 30 minutos. Duas soluções de água do mar enriquecida foram testadas: von Stosch (VSS) nas concentrações reduzidas a 12,5% e 25%; e Provasoli (PES) nas concentrações reduzidas de 25% e 50%, e 100%. A irradiância foi de 45 µmol fótons m -2 s -1 . Num outro experimento, utilizando-se PES 100%, dois tipos de fontes luminosas (lâmpadas fluorescentes Osram 40 W luz do dia e Sylvania Designer 3.500) foram testadas em duas irra...

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“…Given the importance of the agarophyte seaweeds, the changes in biochemical constituents following N addition have been extensively investigated in Gracilaria species in outdoor culture systems on a long-term basis (Bird et al 1981, 1982, Lapointe 1981, Lapointe & Duke 1984, Levy & Friedlander 1990, Fnedlander et al 1991, Haglund & Pedersen 1993. However, little information exists regarding the biochemical processes that govern responses to NH,+ pulses on a short-term basis (hours) in red algae.…”

Section: Introductionmentioning

confidence: 99%

Nitrogen assimilation following NH4+ pulses in the red alga Gracilariopsis lemaneiformis:effect on C metabolism

Jj¹,

Kt²,

Fx³

1995

Mar. Ecol. Prog. Ser.

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Nitrogen assimilation following NH4+ pulses in the red alga Gracilariopsis lemaneiformis: effect on C metabolism Juan J. V e r g a r a l , Kimon T. ~i r d~, F. X. ~i e l l~ ABSTRACT: The short-term effect of external NH,' availability on N assimilation, as well as on C metabolism, has been studied in the red alga Gracilariopsis lemaneiformis. This agarophyte seaweed showed a high capacity to take up external NH,' and to channel it toward proteins. As in a previous study in Corallina elongata, it appears that N limitation redirected the flow of internal N toward nonpigmented proteins, whereas phycobiliprotein synthesis was preferentially stimulated with respect to other proteins in response to external NH,+ pulses. A possible mechanism by which chloroplastic protein synthesis is limited by external N availability more than cytosolic proteins could be involved. In relation to C metabolism, insoluble and soluble carbohydrates were mobilized in response to NH,+ assimilation at a non-saturating irradiance for photosynthesls of 80 pm01 m-2 S-'. The main change in C metabolism was not seen for total C. The principal effect was the flow of C among different compounds, from carbohydrates to organic N compounds (amino acids and prote~ns) during transient NH, + assimilation.

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Strain Selection in Gracilaria spp. I. Growth, Pigment, and Carbohydrates Characterization of Strains of G. conferta and G. verrucosa (Rhodophyta, Gigartinales)

Cited by 32 publications

References 14 publications

A bacterial facultative parasite of Gracilaria conferta

A bacterial facultative parasite of Gracilaria conferta

Growth of red and green strains of the tropical agarophyte Gracilaria cornea J. Agardh (Gracilariales, Rhodophyta) in laboratory

Nitrogen assimilation following NH4+ pulses in the red alga Gracilariopsis lemaneiformis:effect on C metabolism

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