Influence of ammonium-N pulse concentrations and frequency, tank condition and nitrogen starvation on growth rate and biochemical composition ofGracilaria gracilis

Smit, Albertus J.; Robertson, B. L.; Preez, Derek R. du

doi:10.1007/bf02186325

Cited by 44 publications

(26 citation statements)

References 30 publications

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“…Field observations have demonstrated a higher C reserve in M. spicatum than in many submersed macrophytes, e.g., V. natans, C. demersum, Hydrylla verticilata, P. crisp and Vallisneria americana (Titus and Adams 1979;Cao et al, 2008). Interestingly, the contents of SC and starch were positively correlated with the contents of NH 4 N and FAA in M. spicatum, while negative relationships among these metabolites were observed in C. demersum in our study and reported for seagrass Gracilaria gracilis (Smit et al, 1996), indicating species-specific strategies in CN metabolism of the plants in response to external NH 4 + pulse. According to a trade-off of resource use, there are acquisitive and conservative strategies in plants; the former species are geared towards high resource acquisition rates and high growth rates, whereas, the latter species are geared towards high resource conservation, high stress tolerance, and high survival (Sterck et al, 2011).…”

Section: Discussionsupporting

confidence: 65%

“…In aquatic ecosystems, massive input of sewage and agricultural runoff following heavy rain (Junk et al, 1989;Nowlin et al, 2008) can lead to several-fold increases in nutrient concentrations (e.g., ammonium, nitrate, or phosphate) in the water column. Several studies have showed the importance of resource pulses in affecting interactions of macroalgae, epiphytes, and grazers (Worm and Sommer 2000), interaction of zooplankton and phytoplankton (Cottingham and Schindler 2000;Cottingham et al, 2004), and growth of seagrass (Smit et al, 1996;Brun et al, 2002), however, the effect of nutrient pulse on submersed freshwater macrophytes is unknown yet.…”

Section: Introductionmentioning

confidence: 99%

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Nitrogen/carbon metabolism in response to NH4+ pulse for two submersed macrophytes

Yuan

Zhong

et al. 2015

Aquatic Botany

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Section: Discussionsupporting

confidence: 65%

Section: Introductionmentioning

confidence: 99%

Nitrogen/carbon metabolism in response to NH4+ pulse for two submersed macrophytes

Yuan

Zhong

et al. 2015

Aquatic Botany

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“…Essa resposta pode ser explicada pelo estado nutricional das algas. As linhagens foram cultivadas por duas semanas em água do mar esterilizada sem adição de nutrientes, e durante esse período, as algas consumiram suas reservas, como proteínas e pigmentos, para sustentar a sobrevivência e o crescimento (Smit et al 1997 Ao comparar a atividade da NR apresentada pelas linhagens VC e MA de H. musciformis cultivadas em meio com apenas nitrato e com nitrato e fosfato (tabela 1), observou-se um aumento signifi cativo na atividade enzimática com a presença de fosfato no meio, principalmente para a linhagem VC. Tem sido considerado que o fosfato estimula a atividade da NR, embora uma parte do seu efeito indutor possa ser resultado de um incremento na força iônica, quando esse fator não é adequadamente controlado (Nicholas & Scawin 1956, Huber et al 1994.…”

Section: Discussionunclassified

Ensaio in vitro da enzima nitrato redutase e efeito da disponibilidade de nitrato e fosfato em variantes pigmentares de Hypnea musciformis (Wulfen) J. V. Lamour. (Gigartinales, Rhodophyta)

Martins¹,

Chow²,

Yokoya³

2009

Rev. bras. Bot.

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-(In vitro assay of nitrate reductase enzyme and effect of nitrate and phosphate availability in colour strains of Hypnea musciformis (Wulfen) J. V. Lamour. (Gigartinales, Rhodophyta)). The enzyme nitrate reductase (NR) catalyzes the reduction of nitrate to nitrite and controls the rate of nitrate assimilation. The in vitro assay of NR was optimized for the wild strain (brown, MA), and the phycoerythrin-defi cient strain (light-green, VC) of Hypnea musciformis. Both strains were cultured at temperature of 23 ± 2 °C, photoperiod of 14 h, irradiance of 60-90 μmol photons m -2 s -1 , with medium composed by sterilized seawater (salinity 30 psu) with 50% von Stosch's enrichment solution (VSES/2). The optimal conditions for in vitro assay of NR were: 40 μM of NADH; 10 min of incubation of crude extracts (EB), and 100 μL of EB to both strains. Optimal activity of NR occurred at 4 and 2 mM of nitrate to the VC and MA strains, respectively. The VC and MA strains showed, respectively, Michaelis-Menten constants (K M ) for NADH of 0.2068 and 0.0837 μM, and K M for nitrate of 0.0492 and 0.0294 mM. The results indicate that the NR of MA strain has higher affi nity by the substrate than the NR of VC strain of H. musciformis. Experiments on the effects of availabilities of nitrate (5 to 105 μM) and nitrate and phosphate (0.5 to 25.5 μM, with a N:P relation of 4:1) showed that NR activity of VC and MA strain did not increase with the addition of nitrate to the medium, what can be related with their nutritional state. The NR activity was higher in treatments with phosphate addition than those with only nitrate addition, indicating that this nutrient is important to metabolic processes related to the NR activity.Key words -colour strain, Hypnea, nitrate, nitrate reductase, phosphate RESUMO -(Ensaio in vitro da enzima nitrato redutase e efeito da disponibilidade de nitrato e fosfato em variantes pigmentares de Hypnea musciformis (Wulfen) J. V. Lamour. (Gigartinales, Rhodophyta)). A enzima nitrato redutase (NR) catalisa a redução do nitrato a nitrito e controla a taxa de assimilação do nitrato. O ensaio in vitro da nitrato redutase foi otimizado para a linhagem selvagem (marrom, MA) e para a linhagem defi ciente em fi coeritrina (verde-clara, VC) de Hypnea musciformis. As duas linhagens foram cultivadas em temperatura de 23 ± 2 °C, fotoperíodo de 14 horas, irradiância de 60-90 μmol fótons m -2 s -1 , e meio composto por água do mar esterilizada (30 ups) enriquecida com a solução de von Stosch na concentração de 50% (VSES/2). As condições ótimas de ensaio para ambas as linhagens foram: 40 μM de NADH; 10 min de incubação do extrato bruto (EB) e 100 μL de EB. A atividade ótima da NR ocorreu em 4 e 2 mM de nitrato para a linhagem VC e MA, respectivamente. As linhagens VC e MA apresentaram, respectivamente, constante aparente de Michaelis-Menten (K M ) para NADH de 0,2068 e 0,0837 μM, e K M para nitrato de 0,0492 e 0,0294 mM. Os resultados indicam que a NR da linhagem MA tem maior afi nidade pelo substrato do que a NR da linha...

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“…Dortch et al (1984) also observed that the proteins associated with the chlorophyll-protein complex decreased in nitrogen starved cultures. Smit et al (1997) reported a positive relationship between protein and chlorophyll a. Chlorophyll a is one of the most important nitrogen pool in algae: the pigment may reduce nitrogen limitation. In some groups, as in cyanobacteria, where proteins are also associated with the biliproteins (Stanier 1977), these pigments may account for 40% to 50% of the total cell protein.…”

Section: Discussionmentioning

confidence: 99%

Effect of nitrate and ammonium on the growth and protein concentration of Microcystis viridis Lemmermann (Cyanobacteria)

Rückert¹,

Giani²

2004

Rev. bras. Bot.

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-(Effect of nitrate and ammonium on the growth and protein concentration of Microcystis viridis Lemmermann (Cyanobacteria)). Cyanobacteria are a very important group in aquatic systems, particularly in eutrophic waters. Therefore studies about their success in the environment are essential. Many hypotheses have tried to explain the dominance of Cyanobacteria, and several emphasized the importance of various nitrogen sources for the success of the group. In this study, we measured the effect of ammonium and nitrate on the growth and protein concentration of Microcystis viridis (Cyanobacteria). This species is well-known because bloom formation in eutrophic waters. The study was carried out, in experimental batch cultures, using the WC medium with different nitrogen sources: ammonium, nitrate, ammonium + nitrate (50% ammonium + 50% nitrate) and ammonium at different concentrations (to test for possible NH 4 + toxicity). Protein, ammonium and nitrate concentrations were measured at end of each experiment, whereas samples for cell counts were taken daily. Results showed that Microcystis viridis grew faster with ammonium (µ = 0.393 day ) and ammonium + nitrate (µ = 0.325 day -1 ). This pattern is explained by the metabolism of ammonium that presents higher uptake and assimilation rates than nitrate. Maximum cell concentration, however, was higher in the ammonium + nitrate treatment, followed by nitrate treatment. Higher protein concentration were observed in the treatment with nitrate. In the ammonium toxicity test, no difference between the control and NH 4 + at 50% was found. Thus, the ammonium concentrations used in these experiments were not toxic. Our results suggest that Cyanobacteria is able to grow on both nitrogen sources even if ammonium may allow faster growth and bloom development.Key words -ammonium, Cyanobacteria, eutrophication, growth, nitrate, protein concentration RESUMO -(Efeito do nitrato e amônio sobre o crescimento e a concentração de proteínas de Microcystis viridis Lemmermann (Cyanobacteria)). As cianobactérias são um grupo muito importante em sistemas aquáticos, particularmente nos sistemas eutrofizados. Por isso, estudos sobre o sucesso desse grupo são essenciais. Muitas hipóteses têm tentado explicar a dominância de Cyanobacteria e várias enfatizam a importância de fontes nitrogenadas para o sucesso delas. Neste estudo, foi avaliado o efeito dos íons amônio e nitrato sobre o crescimento e a concentração protéica de Microcystis viridis (Cyanobacteria). Esta espécie é bem conhecida por apresentar florações em águas eutróficas. O estudo foi conduzido em culturas do tipo "batch", usando o meio WC com diferentes fontes nitrogenadas: amônio, nitrato, amônio + nitrato (50% amônio + 50% nitrato), e amônio em diferentes concentrações (para testar o possível efeito tóxico de NH 4 + ). Amostras para contagem celular foram retiradas diariamente. As concentrações de proteína, amônio e nitrato foram medidas ao final dos experimentos. Os resultados mostraram que Microcystis viridis cresceu mais r...

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Influence of ammonium-N pulse concentrations and frequency, tank condition and nitrogen starvation on growth rate and biochemical composition ofGracilaria gracilis

Cited by 44 publications

References 30 publications

Nitrogen/carbon metabolism in response to NH4+ pulse for two submersed macrophytes

Nitrogen/carbon metabolism in response to NH4+ pulse for two submersed macrophytes

Ensaio in vitro da enzima nitrato redutase e efeito da disponibilidade de nitrato e fosfato em variantes pigmentares de Hypnea musciformis (Wulfen) J. V. Lamour. (Gigartinales, Rhodophyta)

Effect of nitrate and ammonium on the growth and protein concentration of Microcystis viridis Lemmermann (Cyanobacteria)

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