Potassium chloride and rare earth elements improve plant growth and increase the frequency of the Agrobacterium tumefaciens-mediated plant transformation

Plant transformation efficiency depends on the ability of the transgene to successfully interact with plant host factors. Our previous work and the work of others showed that manipulation of the activity of host factors allows for increased frequency of transformation. Recently we reported that exposure of tobacco plants to increased concentrations of ammonium nitrate increases the frequency of both homologous recombination and plant transgenesis. Here we tested the influence of KCl and salts of rare earth elements, Ce and La on the efficiency of Agrobacterium-mediated plant transformation. We found that exposure to KCl, CeCl₃ and LaCl₃ leads to an increase in recombination frequency in Arabidopsis and tobacco. Plants grown in the presence of CeCl₃ and LaCl₃ had higher biomass, longer roots and greater root number. Analysis of transformation efficiency showed that exposure of tobacco plants to 50 mM KCl resulted in ~6.0-fold increase in the number of regenerated calli and transgenic plants as compared to control plants. Exposure to various concentrations of CeCl₃ showed a maximum increase of ~3.0-fold in both the number of calli and transgenic plants. Segregation analysis showed that exposure to KCl and cerium (III) chloride leads to more frequent integrations of the transgene at a single locus. Analysis of transgene intactness showed better preservation of right T-DNA border during transgene integration. Our data suggest that KCl and CeCl₃ can be effectively used to improve quantity and quality of transgene integrations.     

Culture medium optimization for camptothecin production in cell suspension cultures of Nothapodytes nimmoniana (J. Grah.) Mabberley

The effect of culture medium nutrients on growth and alkaloid production by plant cell cultures of Nothapodytes nimmoniana (J. Grah.) Mabberley (Icacinaceae) was studied with a view to increasing the production of the alkaloid camptothecin, a key therapeutic drug used for its anticancer properties. Amongst the various sugars tested with Murashige and Skoog (MS) medium, such as glucose, fructose, maltose, and sucrose, maximum accumulation of camptothecin was observed with sucrose. High nitrate in the media supports the biomass, while high ammonium enhances the camptothecin content. Selective feeding of 60 mM total nitrogen with a NH₄ ⁺/NO₃ ^? balance of 5/1 on day 15 of the culture cycle results in a 2.4-fold enhancement in the camptothecin content over the control culture (28.5 μg/g DW). Furthermore, the sucrose feeding strategy greatly stimulated cell biomass and camptothecin production. A modified MS medium was developed in the present study, which contained 0.5 mM phosphate, a nitrogen source feeding ratio of 50/10 mM NH₄ ⁺/NO₃ ^? and 3 % sucrose with additional 2 % sucrose feeding (added on day 12 of the cell culture cycle) with 10.74 μM naphthaleneacetic acid and 0.93 μM kinetin. Finally, the selective medium has 1.7- and 2.3-fold higher intracellular and extracellular camptothecin content over the control culture (29.2 and 8.2 μg/g DW), respectively.     

Dose-Dependent Differential Effects of In Vivo Exposure of Cadmium on Myometrial Activity in Rats: Involvement of VDCC and Ca<Superscript>2+</Superscript>-Mimicking Pathways

Present study was undertaken to study the effect of 28-days exposure of female adult rats to cadmium (Cd) in drinking water @ 3, 10 and 30 parts per million (ppm) on myometrial responsiveness to different spasmogens and unravel the possible mechanism of alterations in myometrial activity. Cadmium and Ca²⁺ levels in blood and uterus were measured by atomic absorption spectroscopy while isometric tension in myometrial strips was measured using data acquisition system-based physiograph. Dose-dependent increase in levels of cadmium was observed in both blood and uterus while calcium was increased only in the uterus as compared to those in control. Significant increase in absolute tension and mean integral tension along with non-significant increase in frequency of myometrial contraction was observed in rats of Cd-treated groups. As compared to the control, cadmium decreased and increased the effects of calcium chloride, 80 mM KCl, histamine (0.1 μM) and oxytocin (10^?2 IU/ml) in lower-dose (3 ppm) and higher-dose groups (10 and 30 ppm), respectively. Cadmium potentiated and inhibited the relaxant response to phenylephrine in myometrium of rats at lower-dose (3 ppm) and highest-dose (30 ppm) Cd-treated groups, respectively. Results of our study revealed that Cd accumulates in the myometrium of rats and alters its responsiveness to oxytocin, histamine, 80 mM KCl, calcium chloride and phenylephrine, and these effects are differentially mediated depending on levels of exposure possibly through voltage-dependent calcium channel (VDCC) and Ca²⁺-mimicking pathways.     

Manipulation of culture strategies to enhance capsaicin biosynthesis in suspension and immobilized cell cultures of Capsicum chinense Jacq. cv. Naga King Chili

Manipulation of culture strategies was adopted to study the influence of nutrient stress, pH stress and precursor feeding on the biosynthesis of capsaicin in suspension and immobilized cell cultures of C. chinense. Cells cultured in the absence of one of the four nutrients (ammonium and potassium nitrate for nitrate and potassium stress, potassium dihydrogen orthophosphate for phosphorus stress, and sucrose for sugar stress) influenced the accumulation of capsaicin. Among the stress factors studied, nitrate stress showed maximal capsaicin production on day 20 (505.9 ± 2.8 μg g^?1 f.wt) in immobilized cell, whereas in suspension cultures the maximum accumulation (345.5 ± 2.9 μg g^?1 f.wt) was obtained on day 10. Different pH affected capsaicin accumulation; enhanced accumulation of capsaicin (261.6 ± 3.4 μg g^?1 f.wt) was observed in suspension cultures at pH 6 on day 15, whereas in case of immobilized cultures the highest capsaicin content (433.3 ± 3.3 μg g^?1 f.wt) was obtained at pH 5 on day 10. Addition of capsaicin precursors and intermediates significantly enhanced the biosynthesis of capsaicin, incorporation of vanillin at 100 μM in both suspension and immobilized cell cultures resulted in maximum capsaicin content with 499.1 ± 5.5 μg g^?1 f.wt on day 20 and 1,315.3 ± 10 μg g^?1 f.wt on day 10, respectively. Among the different culture strategies adopted to enhance capsaicin biosynthesis in cell cultures of C. chinense, cells fed with vanillin resulted in the maximum capsaicin accumulation. The rate of capsaicin production was significantly higher in immobilized cells as compared to freely suspended cells.     

High frequency <Emphasis Type="Italic">Agrobacterium tumefaciens</Emphasis>-mediated plant transformation induced by ammonium nitrate

Success in plant genetic transformation depends on the efficiency of explant regeneration and transgene integration. Whereas the former one depends on explant totipotency, the latter depends on the activity of host DNA repair and chromatin organisation factors. We analyzed whether factors that result in an increase in recombination frequency can also increase transformation efficiency. Here, we report that a threefold increase in the concentration of NH₄NO₃ in the growth medium results in more than a threefold increase in the Agrobacterium tumefaciens-mediated transformation frequency of Nicotiana tabacum plants. Regeneration of calli without selection showed that the increase in transformation frequency was primarily due to the increase in transgene integration efficiency rather than in tissue regeneration efficiency. PCR analysis of insertion sites showed a decrease in the frequency of truncations of the T-DNA right border and an increase on the left border. We hypothesize that exposure to ammonium nitrate modifies the activity of host factors leading to higher frequency of transgene integrations and possibly to the shift in the mechanism of transgene integrations. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Nitrogen-stimulated potassium influx into maize roots: differential response of components resistant and sensitive to ambient ammonium1

Abstract Potassium (⁸⁶Rb) influx from 200 mmol m ^?3 KCl into dark grown, decapitated maize seedlings 6 d old) was stimulated by nitrate pretreatment. The stimulus was clearly evident by 6h exposure to nitrate and required 12–24 h for maximal expression. Decay of the nitrate-stimulated potassium influx was more than 50% complete within 3 h after transfer to nitrogen-free solutions. The stimulation of potassium influx was entirely accounted for by an increase in the influx component that was resistant to inhibition by presence of 200 mmol m^?3 ambient ammonium. In contrast, the component of potassium influx that was sensitive to inhibition by ambient ammonium was unaffected by nitrate pretreatment. Exposure to the glutamine synthetase inhibitor L-methionine-dl-sulphoximine (MSX) during nitrate pretreatment stimulated the resistant component but the sensitive component was nearly eliminated. Pretreatment with ammonium increased the resistant component of potassium influx within 3 h, i.e. before it was increased by nitrate pretreatment, but the sensitive component was concomitantly restricted. The latter recovered partially during extended pretreatment with ammonium. The data indicate that the resistant component responded positively to increases in tissue ammonium concentrations whereas the sensitive component was unaffected by tissue ammonium except at concentrations in excess of 10μmol g^?1. Ammonium influx was also stimulated by nitrate pretreatment and to a greater extent than potassium influx. Presence of MSX with nitrate during pretreatment resulted in a further stimulation in ammonium influx. The parallel increases in root ammonium concentrations with the two pretreatments imply that part of the increase in ammonium influx was a consequnce of increased counter-transport with endogenous ammonium.     

Physiological responses and biofilter potential of <Emphasis Type="Italic">Hypnea aspera</Emphasis> (Rhodophyta,Gigartinales) cultivated in different availabilities of nitrate,ammonium, and phosphate

Along with the search for new species of seaweeds with biofilter capacity, it is also necessary to understand the physiological and biochemical responses of these seaweeds cultivated in different availabilities of nitrate, ammonium, and phosphate. To accomplish this, a laboratory study was performed to evaluate the ability of Hypnea aspera Kützing (Gigartinales, Rhodophyta), to growth under different nitrate, ammonium, and phosphate availabilities and to uptake, assimilate, and remove these nutrients from seawater. Treatments were composed of sterilized seawater enriched with quarter-strength von Stosch’s nutrient solution modified (without any nitrogen and phosphorus compounds). Nitrate or ammonium, together with phosphate, was added in combined N/P ratios of 100:1 and 10:1. Nitrate concentrations varied from 0 to 150 μM, and ammonium concentrations varied from 0 to 70 μM. Growth rates of H. aspera increased with nitrate addition, and the highest value was 4.68 ± 0.76 % day^?1 in 150 μM, but the addition of high ammonium concentration (70 μM) in N/P ratio of 10:1 inhibited the growth rates (?3.89 ± 1.03 % day^?1). Nitrogen was accumulated as proteins and phycobiliproteins, mainly phycoerythrin, at higher phosphate availability (N/P ratio of 10:1) for nitrate addition (150 μM for proteins and 50, 100, and 150 μM for phycoerythrin), and lower phosphate availability (N/P ratio of 100:1) for ammonium addition (50 and 70 μM for proteins and 50 μM for phycoerythrin). Nitrogen and phosphate were assimilated into thallus in all treatments with nutrient addition. Hypnea aspera showed high removal efficiency (higher than 90 %) of nitrate, nitrite, ammonium, and phosphate present in the seawater. These results suggest that H. aspera could be cultivated in integrated multitrophic aquaculture systems to reduce nutrient loading in eutrophic seawater.     

Advantages of rubidium chloride gradients for isopycnic centrifugation of enzymes

The isopycnic centrifugation of beta-amylase and the marker enzyme beta-galactosidase was carried out using four salts viz. rubidium chloride, potassium bromide, potassium acetate and lithium bromide. Lithium bromide inactivated both beta-galactosidase and beta-amylase. The high viscosity of potassium acetate gradients necessitated an extremely long centrifugation time. The density profiles obtained with rubidium chloride gradients were sharper and permitted better resolution than potassium bromide gradients. Both enzymes were stable in rubidium chloride gradients, while potassium bromide inactivated beta-galactosidase, even in the presence of 10 mM 2-mercaptoethanol.     

Freezing of isolated thylakoid membranes in complex media: I. The effect of potassium and sodium chloride,nitrate, and sulfate

Thylakoid membranes isolated from spinach leaves (Spinacia oleracea L. cv. Monatol) were subjected to a freeze-thaw cycle in the presence of a buffered medium containing sorbitol as a cryoprotectant and various combinations of potassium and sodium chloride, nitrate, and sulfate. Above a certain total salt concentration, an increase in the concentration of a single electrolyte, or of potassium plus sodium salts with identical anions, always led to a decrease in photophosphorylation activity. A similar effect was obtained with combinations of nitrate plus chloride with identical cations and of KNO₃ plus NaCl. By contrast, in the presence of suitable combinations of NaNO₃ plus KCl, NaNO₃ plus sulfates, and chlorides plus sulfates, inactivation of photophosphorylation was diminished, sometimes dramatically, at initial molarities of nitrate or chloride which alone caused partial or complete membrane damage. When NaNO₃, KCl, and potassium or sodium sulfate were simultaneously present during freezing, thylakoids were affected very little over a wide range of concentration. Diminution or prevention of inactivation of photophosphorylation by suitable combinations of two or more cryotoxic inorganic salts can be explained by postulating that the different solutes act on different sites and that each reduces the concentration of the others by colligative action, together with specific effects of the various electrolytes on individual membrane sites.     

Factors affecting genetic transformation and shoot organogenesis of Bacopa monnieri (L.) Wettst

Efficient Agrobacterium tumefaciens mediated T-DNA delivery and subsequent shoot organogenesis has been achieved from Bacopa monnieri. Various factors influenced T-DNA delivery as evident from transient GUS assay. The transient GUS expression was significantly higher (97.7 %) in explants that were pre-cultured before bacterial infection on medium supplemented with 100 μM acetosyringone. Incorporation of acetosyringone into the co-cultivation medium also enhanced transient GUS activity. Explant injury with carborundum paper, co-cultivation period of 2 days and a bacterial density of 0.4 OD₆₀₀ showed higher transient GUS expression. Following co-cultivation, shoot organogenesis was achieved from leaf segments on basal Murashige and Skoog medium containing 58 mM sucrose. Supplementation of antibiotics (cefotaxime or carbenicillin) at > 250 μg/ml into the medium significantly promoted shoot organogenesis from leaf explants (71.5 % in control and > 83.0 % on medium containing 500 μg/ml of carbenicillin or cefotaxime). Stable transformation of regenerated shoots was confirmed on the basis of GUS activity and PCR amplification of DNA fragments specific to reporter gene (uidA) and selection marker gene (nptII). The expression level of nptII gene in independent transgenic lines was studied using quantitative real time-PCR. Stable transformed shoots after rooting were successfully established in the pots.     

Efficiency of different Agrobacterium rhizogenes strains on hairy roots induction in Solanum mammosum

This article presents the abilities and efficiencies of five different strains of Agrobacterium rhizogenes (strain ATCC 31798, ATCC 43057, AR12, A4 and A13) to induce hairy roots on Solanum mammosum through genetic transformation. There is significant difference in the transformation efficiency (average number of days of hairy root induction) and transformation frequency for all strains of A. rhizogenes (P < 0.05). Both A. rhizogenes strain AR12 and A13 were able to induce hairy root at 6 days of co-cultivation, which were the fastest among those tested. However, the transformation frequencies of all five strains were below 30 %, with A. rhizogenes strain A4 and A13 showing the highest, which were 21.41 ± 10.60 % and 21.43 ± 8.13 % respectively. Subsequently, the cultures for five different hairy root lines generated by five different strains of bacteria were established. However, different hairy root lines showed different growth index under the same culture condition, with the hairy root lines induced by A. rhizogenes strain ATCC 31798 exhibited largest increase in fresh biomass at 45 days of culture under 16 h light/8 h dark photoperiod in half-strength MS medium. The slowest growing hairy root line, which was previously induced by A. rhizogenes strain A13, when cultured in optimized half-strength MS medium containing 1.5 times the standard amount of ammonium nitrate and potassium nitrate and 5 % (w/v) sucrose, had exhibited improvement in growth index, that is, the fresh biomass was almost double as compared to its initial growth in unmodified half-strength MS medium.     

Bioremediation potential of Palmaria palmata and Chondrus crispus (Basin Head): effect of nitrate and ammonium ratio as nitrogen source on nutrient removal

Palmaria palmata and Chondrus crispus were grown for 4 weeks in 1-L flasks at 10 °C to evaluate nutrient uptake and their potential application as nutrient biofilters in effluent from finfish culture. For greatest bioremediation benefit within an integrated system, we conclude that a seaweed biofilter using these species should be placed prior to bacterial biofiltration for exposure to greater proportions of ammonium than nitrate, though it is apparent that the productivity of both species is not influenced by the nitrogen source. Five combinations of ammonium– and nitrate–nitrogen were compared, each with a total N concentration of 300 μM (300:0, 270:30, 150:150, 30:270, 0:300). Molar nitrogen/phosphorus ratio was 10:1. The maximum growth rates were 8.9 and 6.0 % per day for P. palmata and C. crispus, respectively. For both species, the total nitrogen uptake was highest at 300 μM ammonium, 4.46 mgN gDW^?1 day^?1 for P. palmata and 3.40 mg?N? g?DW^?1?day^?1 for C. crispus. Over a 24-h period, 23–37 % of the available nitrate and 91–100 % of the available ammonium were taken up by P. palmata. In the same period, C. crispus took up 55–87 % of available nitrate and 89–100 % of ammonium. Tissue N in P. palmata was highest (4.1 %) at 270 and 300 μM ammonium, while the nitrogen source did not have a significant effect on the tissue N of C. crispus (mean of 4.6 %).     

Nitrogen and sulphur requirements of Colletotrichum inamdarii Lal

Summary Nitrogen and sulphur requirements ofColletotrichum inamdarii Lal isolated from the leaves ofCarissa carandas L. have been studied. DL-serine, L-asparagine and L-phenylalanine have been found to be of good nitrogen source followed by potassium nitrate, calcium nitrate, magnesium nitrate, DL-alanine, ammonium nitrate, glutamic acid, ammonium sulphate, DL-valine, aspartic acid, ammonium chloride, ammonium hydrogencarbonate, L-histidine and potassium nitrite. There was no growth in the absence of nitrogen.Sporulation was excellent on calcium nitrate and sodium nitrate, Very good on DL-serine, potassium nitrate, and magnesium nitrate. Good on L-asparagine, L-phenylalanine and ammonium oxalate. Fair on DL-alanine, DL-leucine, ammonium sulphate, DL-valine, ammonium chloride and L-histidine whereas poor on glutamic acid, aspartic acid, ammonium tartarate and ammonium nitrate. Few spores were observed on ammonium hydrogencarbonate but potassium nitrite did not show any sporulation.Amongst the sulphur compounds sodium bisulphate gave the best growth and good sporulation, followed by sodium thiosulphate, magnesium sulphate, ammonium sulphate and potassium sulphate. Thiourea gave negligible growth whereas it failed to grow on zinc sulphate and potassium persulphate.     

The inhibitory effect of Ca2+ on the flavonoid production of Tetrastigma hemsleyanum suspension cells induced by metal elicitors

Tetrastigma hemsleyanum suspension cells were treated with four metal salts to screen suitable elicitors for the promotion of plant cell biomass and flavonoid production. The effects of calcium ions (Ca²⁺) on induction were also studied. It was found that the most effective elicitors were 50 μM of the heavy metal ion copper (Cu²⁺) and 100 μM of the rare earth element cerium (Ce³⁺). The maximal biomass levels under respective treatments over a 16-d culture period increased by 1.3- and 1.6-fold, and the total flavonoid content was 1.8- and 1.6-fold greater than the control, respectively. Reducing the exogenous Ca²⁺ concentration or adding Ca²⁺ antagonists (1 mM ethylene glycol-bis(2-aminoethylether)-N,N,N′,N-tetraacetc acid (EGTA) or 1 mM verapamil) strengthened inductive effects of metal elicitors and enhanced flavonoid production. However, 0.5 μM of the calcium ionophore A23187 showed contrary results. The increase in exogenous Ca²⁺ concentration in the presence of A23187 suppressed H₂O₂ bursts and peroxidase activity caused by metal elicitors. The results suggest that Ca²⁺ plays an inhibitory role in the plant cell response to metal elicitors. This suppression could have been caused by Ca²⁺ preventing the cells from absorbing metal ions and then easing the induction, or because the decrease of Ca²⁺ concentration worked as an induction signal. Therefore, reducing the Ca²⁺ concentration in culture medium, or adding Ca²⁺ antagonists could be used to improve flavonoid production and cell growth in combination with induction by metal elicitors during in vitro culture of T. hemsleyanum suspension cells.     

The effect of chloride on nitrate reductase level,on anaerobic nitrite production,and on nitrate content in excisedPisum sativum L. roots

The effect was studied of chloride ions, added in the form of different salts, on nitrate reductase (NR) level in excised pea roots, on anaerobic nitrite production in an assay medium lacking both nitrate and n-propanol, on nitrate content in the roots, and on in vivo NR activity determined in an assay medium containing 5% n-propanol. The presence of Cl in nitrate containing nutrient solutions resulted in lower NR levels, however counterions supplied together with Cl tended to modify slightly this general trend. The negative effect of Cl ions was also apparent, when Cl ions were applied before nitrate ions. Anaerobic nitrite production in the medium lacking both nitrate and n-propanol was not influenced by chloride ions. Nitrate content in the roots was reduced in the presence of chloride both at 3 mM and 15 mM NO₃ in nutrient solutions; however, at 16 mM NO₃, nitrate content in the roots exoeeded even in the presence of 15 mM Cl nitrate content in those root segments which were cultivated in a nutrient solution with 6 mM nitrate, which is the concentration at which NR reaches the level of saturation in excised pea roots. The results obtained suggest that a special induction nitrate pool exists in plant cells besides the storage and metabolic nitrate pools.     

High nitrogen supply affects the metabolism of Matricaria chamomilla leaves

N-status of the two Matricaria chamomilla cultivars grown in the presence of high potassium nitrate concentration was evaluated and compared with ammonium nitrate supply. After 5 days of potassium nitrate treatment the visible increase of dry mass together with total chlorophyll accumulation were observed. In both cultivars, ammonium nitrate application led to increased accumulation of N-containing compounds in chamomile leaves. NH₄NO₃ nitrogen supply influenced activity of nitrate reductase positively. In vivo nitrate reductase activity reached maximum in lower nitrate supply and decreased in higher nitrate availability significantly. Among the most abundant leaf secondary metabolites, the high nitrate availability both KNO₃ and NH₄NO₃ significantly increased umbelliferone level. The highest potassium nitrate dose (60 mmol per plant) caused an osmotic stress accompanied with lower tissue water content and turgor loss. In such condition the decrease in (Z)- and (E)-2-β-d-glucopyranosyloxy-4-methoxycinnamic acid, herniarin and dicycloethers, as well as PAL activity was observed. On the other hand, strong increase of umbelliferone is likely a stress response and is related to its antioxidant activity.     

The Influence of Inorganic Salts on the Combustion of Cigarette and on the Transfer of Nicotine on to Smoke

The effects of several inorganic salts on the combustion of cigarette and the transfer of nicotine into cigarette smoke have been investigated. Ferric, ferrous, ammonium, magnesium salts and chlorides or sulfates depress the combustibility. Contrary to this, potassium, calcium salts, nitrates and carbonates promote it. The combustion-zone temperatures of cigarettes are within the range from 815°C to 857°C, they are not significantly affected by an addition of inorganic salts. Magnesium nitrate, zinc nitrate and potassium phosphate improve the whiteness of cigarette ash, but the other salts rather darken it. Any relations, however, are not recognized between the whiteness of ash and combustibility of cigarettes. The amounts of nicotine transferred into smoke can be reduced by an addition of inorganic salts, among which magnesium is the most effective.     

Induction of larval settlement and metamorphosis in the donkey-ear abalone,Haliotis asinina Linnaeus,by chemical cues

The effects of the chemical inducers, gamma-aminobutyric acid (GABA) and potassium chloride (KCl), on the larval settlement and metamorphosis of the donkey-ear abalone, Haliotis asinina, was investigated. H. asinina larvae (5–6 h post-hatch) were exposed to a range of GABA (0.125–2.00 μM) and KCl (1.00–12.00 mM) concentrations for 72 h. Results of the dose response experiments showed that settlement and metamorphosis vary according to the dose levels of the inducer compounds. Under controlled laboratory conditions, 0.45–0.50 μM and 6.0 mM seemed to be the optima for GABA and KCl, respectively, as these concentrations elicited the greatest number of postlarvae that metamorphosed, settled or survived. However, GABA generally promoted better attachment and metamorphic response as well as survival than KCl in H. asinina postlarvae.     

Effects of nitrogen and phosphorus availabilities on growth, pigment, and protein contents in Hypnea cervicornis J. Agardh (Gigartinales, Rhodophyta)

The selection of seaweed species for their use as biofilters should be based on the knowledge of their nutrient requirements and tolerance to wide variations of nutrient concentrations. Therefore, tolerance and the physiological capabilities of Hypnea cervicornis J. Agardh (Gigartinales, Rhodophyta) to growth under nitrate, ammonium, and phosphate variations and to assimilate them into soluble proteins and photosynthetic pigments were evaluated in laboratory conditions. Treatments were composed of sterilized seawater enriched with 25 % von Stosch solution (without nitrogen and phosphorus), and nitrate or ammonium and phosphate were added in combination of 100:1 and 10:1 nitrogen/phosphorus (N/P). Nitrate concentrations varied from 0 to 500 μM, and ammonium concentrations varied from 0 to 50 μM. Growth rates of H. cervicornis increased linearly with addition of ammonium, but with nitrate addition, growth varied following a saturation kinetic, and the highest growth rate (14.45 % d^?1) was observed in 200 μM of N/P ratio of 10:1. An excess of nutrients was accumulated as proteins and phycobiliproteins (mainly as allophycocyanin and phycoerythrin) at higher phosphate availability (N/P ratio of 10:1), and H. cervicornis tolerated the highest ammonium and nitrate concentrations (50 and 500 μM, respectively). These physiological responses suggest that this species could be used as biofilter for nutrient removal in eutrophicated seawater and could be cultivated in integrated multitrophic aquaculture systems.