Cultures Of Isochrysis Galbana Research Articles

Observations on the laboratory culture of the harpacticoid copepod Euterpina acutifrons (Dana, 1847) using different diets

Hatching success, nauplii production, maturation and survival of the harpacticoid copepod Euterpina acutifrons (Dana, 1847) fed on mono/mixed culture of Isochrysis galbana, Tetraselmis gracilis, Chaetoceros calcitrans and Chlorella marina were studied. The time taken for E. acutifrons to mature was the lowest with a diet of I. galbana followed by C. calcitrans. Percentage of survival was highest with a mixed diet of 75% I. galbana and 25% C. calcitrans (84%) followed by T. gracilis (68%). The study also revealed that both feed type and concentration played significant role in production and survival of E. acutifrons. Mixed diet of I.galbana and C. calcitrans showed maximum adult production followed by a diet of T.gracilis. The mean values of all the three stages of the copepod viz., adults, ovigerous females and copepodite-nauplii were found much greater in the treatment with replacement of the culture medium and feed. Mass culture using different organic feeds was also carried out and it was found that mean growth in terms of adult stage production was found to be higher when fed with rice bran followed by groundnut oil cake (GOC) and the least in cow dung treatment. In rice bran treatment, copepodites showed higher production rate when compared to the other two feeds. Mean growth in terms of nauplii production was also higher in rice bran fed group followed by GOC fed group and the least in cow dung treatment.

Simulation Method Linking Dense Microalgal Culture Spectral Properties in the 400-750 nm Range to the Physiology of the Cells.

This work describes a method to model the optical properties over the (400-750 nm) spectral range of a dense microalgal culture using the chemical and physical properties of the algal cells. The method was based on a specific program called AlgaSim coupled with the adding-doubling method: at the individual cell scale, AlgaSim simulates the spectral properties of one model, three-layer spherical algal cell from its size and chemical composition. As a second step, the adding-doubling method makes it possible to retrieve the total transmittance of the algal medium from the optical properties of the individual algal cells. The method was tested by comparing the simulated total transmittance spectra for dense marine microalgal cultures of Isochrysis galbana (small flagellates) and Phaeodactylum tricornutum (diatoms) to spectra measured using an experimental spectrophotometric setup. Our study revealed that the total transmittance spectra simulated for the quasi-spherical cells of Isochrysis galbana were in good agreement with the measured spectra over the whole spectral range. For Phaeodactylum tricornutum, large differences between simulated and measured spectra were observed over the blue part of the transmittance spectra, probably due to non-spherical shape of the algal cells. Prediction of the algal cell density, mean size and pigment composition from the total transmittance spectra measured on algal samples was also investigated using the reversal of the method. Mean cell size was successfully predicted for both species. The cell density was also successfully predicted for spherical Isochrysis galbana, with a relative error below 7%, but not for elongated Phaeodactylum tricornutum with a relative error up to 26%. The pigments total quantity and composition, the carotenoids:chlorophyll ratio in particular, were also successfully predicted for Isochrysis galbana with a relative error below 8%. However, the pigment predictions and measurements for Phaeodactylum tricornutum showed large discrepancies, with a relative error up to 88%. These results give strong support for the development of a promising tool providing rapid and accurate estimations of biomass and physiological status of a dense microalgal culture based on only light transmittance properties.

Lipid and fucoxanthin production in mixed cultures of Isochrysis galbana and Saccharomyces cerevisiae

Event Abstract Back to Event Lipid and fucoxanthin production in mixed cultures of Isochrysis galbana and Saccharomyces cerevisiae Catarina R. Correia1*, Catarina Barraca1*, Catarina R. Mendes1, Joao Chambel1, 2 and Sergio M. Leandro1* 1 MARE – Marine and Environmental Sciences Centre, ESTM, Instituto Politécnico de Leiria, Portugal 2 AQUASPROSEA, Lda, Santuário Nossa Senhora dos Remédios, Portugal The future of aquaculture is correlated with the development, among other aspects, of the dietary elements. Feed applied in this field are in constant evolution, in order to provide a more nutritional and chemical-free solution. One of the new key-elements for the novel feeds in aquaculture is the addition of high quality lipids and natural pigments. Fucoxanthin is one of the most relevant carotenoids in brown microalgae, with several appliances, as antioxidant compound and feed addictive in aquaculture. Since lipids and this pigment have high applications in aquaculture dietary, a more economically feasible approaches for their production are in need. Pure and mixed cultures of Isochrysis galbana and Saccharomyces cerevisiae (dietary strain) were grown autotrophically in batch. Three combinations were tested: (A) Isochrysis galbana + F/2 medium, (B) Isochrysis galbana + half F/2 medium + Saccharomyces cerevisiae and (C) Isochrysis galbana + Saccharomyces cerevisiae. Cultures growth pattern was followed until second day of stationary phase was achieved, by cell manual counting and by dry weight determination. Total lipid content was performed according to modified Bligh and Dyer, total carotenoid content by spectrophotometry UV-VIS and fucoxanthin content by High Pressure Liquid Chromatography. Results attained suggest that the tested growth media did not statistically influenced biomass production, even though specific growth rate and doubling time were biologically different. Combination (A) had a µ=0.2647 d-1, (B) presented µ=0.2089 d-1 and (C) µ=0.1316 d-1. Despite having a lower specific growth-rate, combination (C) began logarithmic phase a day earlier than the other combinations tested, leading to believe that this treatment would require a fed-batch grown. Regarding total carotenoid content, combination (B) achieved higher values (1%), followed by combination (A) (0.44%) and combination (C) (0.04%). For lipid production, the combination (B) presented higher lipid productivity. This outcomes also suggest that mixed cultures of Isochrysis galbana + Saccharomyces cerevisiae, when provided with F/2 medium, are a suitable approach for lipid and fucoxanthin production. Keywords: Microalgae, Mixotrophic growth, Microalgae mass cultivation, Growth Substances, Isochrysis galbana Conference: IMMR | International Meeting on Marine Research 2016, Peniche, Portugal, 14 Jul - 15 Jul, 2016. Presentation Type: Poster presentation Topic: Blue Biotechnology Citation: Correia CR, Barraca C, Mendes CR, Chambel J and Leandro SM (2016). Lipid and fucoxanthin production in mixed cultures of Isochrysis galbana and Saccharomyces cerevisiae. Front. Mar. Sci. Conference Abstract: IMMR | International Meeting on Marine Research 2016. doi: 10.3389/conf.FMARS.2016.04.00056 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 14 May 2016; Published Online: 13 Jul 2016. * Correspondence: Dr. Catarina R Correia, MARE – Marine and Environmental Sciences Centre, ESTM, Instituto Politécnico de Leiria, 2520-641, Portugal, catarinasrcorreia@gmail.com Dr. Catarina Barraca, MARE – Marine and Environmental Sciences Centre, ESTM, Instituto Politécnico de Leiria, 2520-641, Portugal, catarinabarraca6@gmail.com PhD. Sergio M Leandro, MARE – Marine and Environmental Sciences Centre, ESTM, Instituto Politécnico de Leiria, 2520-641, Portugal, sleandro@ipleiria.pt Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Catarina R Correia Catarina Barraca Catarina R Mendes Joao Chambel Sergio M Leandro Google Catarina R Correia Catarina Barraca Catarina R Mendes Joao Chambel Sergio M Leandro Google Scholar Catarina R Correia Catarina Barraca Catarina R Mendes Joao Chambel Sergio M Leandro PubMed Catarina R Correia Catarina Barraca Catarina R Mendes Joao Chambel Sergio M Leandro Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Impact of salinity and growth phase on alkenone distributions in coastal haptophytes

Batch cultures of Isochrysis galbana (strain CCMP 1323) and Chrysotila lamellosa (strain CCMP 1307) were grown at salinity values of ca. 10 to ca. 35 and the alkenone distributions determined for different growth phases. U37K′ values decreased slightly with salinity for C. lamellosa but were largely unaffected for I. galbana, except during the decline phase. The values decreased with incubation time in both species. The proportion of C37:4, used as a proxy for salinity, increased in both species at 0.16–0.20% per salinity unit, except during the stationary phase for I. galbana. C37:4 was much more abundant in C. lamellosa (30–44%) than in I. galbana (4–12%). Although our results suggest that salinity has a direct effect on alkenone distribution, growth phase and species composition should also have a marked impact, complicating the use of the distributions as a proxy for salinity in the marine environment.

Effects of CO2 enrichment and nutrients supply intermittency on batch cultures of Isochrysis galbana

Aiming at enhanced performance to increase economic feasibility of microalgae based processes, Isochrysis galbana was grown in three modes of cultivation: batch, intermittent fed batch and semi-continuous. The batch mode was conducted under two regimes of aeration: conventional aeration and CO2 enriched aeration (5% v/v in air). Increased biomass productivity without significant impact on lipid accumulation was observed for CO2 enriched aeration relatively to cultivation aerated with air only. The intermittent fed batch cultivation policy was proven to be useful for lipid accumulation, increasing the lipid content by 19.8%. However, the semi-continuous mode resulted in higher productivity due to increased biomass concentration; the biomass productivity reached 0.51 g/(Ld). Fluorescence measurements were performed; the calculated low electron transport rate showed the need to increase the irradiance. The results showed that I. galbana can be grown in semi-continuous condition at high levels of biomass productivity.

Growth inhibition of the eight species of microalgae by growth inhibitor from the culture of Isochrysis galbana and its isolation and identification

A type of growth inhibitor was successfully isolated and purified from cell-free filtrates of cultural medium at the death phase of Isochrysis galbana, and its chemical structure was confirmed by the methods of FABMS, UV, 1H-NMR, 13C-NMR and 2D NMR, which was 1-[hydroxyl-diethyl malonate]-isopropyl dodecenoic acid, C22H38O7. The results showed that the growth-inhibitor strongly inhibited the growth of Isochrysis galbana, and the growth of the eight species of microalgae (Dunaliella salina, Platymonas elliptica, Chlorella vugralis, Nitzschia closterium, Chaetoceros muelleri, Chaetoceros gracilis, Nitzschia closterium minutissima, Phaeodactylum tricornutum) also could be regulated by the growth-inhibitor in a concentration-dependent manner. The further investigation found that the synthesis process of chlorophyll and protein in the cells of all test microalgae could be inhibited by the growth inhibitor, and the content of chlorophyll and protein significantly decreased.

Effects of chloramphenicol, erythromycin, and furazolidone on growth of Isochrysis galbana and Chaetoceros gracilis

This study focused on determining the effects of antibiotics on microalgae used as food for scallop larvae. Six different dose levels of chloramphenicol, erythromycin, and furazolidone were added to cultures of Isochrysis galbana and Chaetoceros gracilis. An in vivo experiment was subsequently conducted to determine the effect of chloramphenicol and erythromycin on larval survival of the Pacific calico scallop Argopecten ventricosus in tanks and on the population of its associated bacteria. Results showed that growth of I. galbana was not significantly affected by chloramphenicol or erythromycin at the test doses of 0.5, 1.0, 3.0, 6.0, 9.0, and 12.0 mg/l. C. gracilis was significantly sensitive to erythromycin and chloramphenicol at doses higher than 0.5 and 3.0 mg/l, respectively. Furazolidone inhibited the growth of both I. galbana and C. gracilis at all test doses. Results showed that exposure of scallop larvae to a dose of 6 mg/l chloramphenicol or erythromycin did not significantly affect growth of I. galbana, significantly enhanced survival of the scallop larvae, and inhibited the growth of Vibrio spp. in tanks. This study demonstrated the adverse effect of chloramphenicol, erythromycin and furazolidone on I. galbana and C. gracilis microalgae but the positive effect on survival of the scallop larvae, decreasing associated bacterial population.

Modelling the interacting effects of nutrient uptake, light capture and temperature on phytoplankton growth

A model of phytoplankton growth developed by analogy with chemical kinetics (CR model) in Baird and Emsley (J. Plankton Res., 21, 85‐126, 1999) is explored further. The CR model parameterizes all biochemical reactions involved in phytoplankton growth by one parameter: the maximum growth rate. Phytoplankton growth rate is then calculated from an interaction of the maximum growth rate, and the physical limit to extracellular nutrient uptake rates and light capture. In this paper, the CR model was re-derived, with two corrections and a number of modifications to increase its generality. During derivation, the model’s behaviour was compared with chemostat cultures at a variety of dilution rates, nutrient inputs and temperatures. Model output was then plotted against observations of a semi-continuous culture of Isochrysis galbana. Finally, the CR model was used to predict the growth rate of phytoplankton communities extracted from two temperate lakes under varying nutrient, light and temperature regimes. The CR model explained 37% of the variability of phytoplankton growth rate in cultures at environmental conditions similar to those of the lakes, compared with 25% explained by a non-linear best fit to 324 growth experiments. The following paper in this issue develops the CR model further, using it to predict stable carbon isotope fractionation.

Periodic ammonium pulses: are they important for the uptake kinetics of Isochrysis galbana?

In a megatidal coastal system, high tidal currents can lead to periodic reinjection of nutrients via the water/sediment interface. This study investigates the phytoplankton response to periodic ammonium pulses (every 5h20) in a nitrogen-limited culture of Isochrysis galbana. Results show that cells use additional ammonium. The cell response is not instantaneous and an adaptation period is observed in experiments. This period is characterized by (i) a decrease in latency stage during 10 mn after one pulse, (ii) an alternance of uptake/excretion processes decreasing throughout the experiment, (iii) an increasingly high and rapid surge-uptake phenomenon until pulse 6. We raise the question whether the Michaelis–Menten equation classically used to describe uptake processes is adequate in such an intermittent background.

A comparative study on growth performance and biochemical composition of mixed culture of Isochrysis galbana and Chaetoceros calcitrans with monocultures

The growth performance, biochemical composition and nutritive value of the mixed culture of Isochrysis galbana and Chaetoceros calcitrans, grown in batch cultures under laboratory conditions was compared with those in monoculture conditions. In mixed culture, both species manifested their monoculture characteristics with some variations: I. galbana, as in its monoculture situation, had an initial rapid growth, while the growth rate of C. calcitrans was half that of its monoculture state. However, as the growth rate of C. calcitrans increased gradually during later stages of the experiment that of I. galbana decreased. Although C. calcitrans dominated the mixed culture during later stages, the population of I. galbana was not totally eliminated. Cellular concentrations of chlorophyll a, protein, carbohydrate, lipid and particulate organic carbon in monocultures and mixed culture peaked during the late exponential phase but were significantly higher ( P<0.05) in the mixed culture. The calculated dietary energy content was also significantly higher ( P<0.05) in the mixed culture compared to the monocultures during all the growth phases. The study highlights the nutritional implications of mixed algal cultures in hatcheries, particularly in shrimp hatcheries where different species and size groups of larvae are to be fed.

Establishment of mixed-culture probiotics and microalgae as food for bivalve larvae

Studies were carried out to establish the feasibility of incorporating bacteria with the ability to produce inhibitory substances (BPI) into axenic cultures of Isochrysis galbana with the object of using this microalga as a vector for transmitting BPI into cultures of larval bivalves as antagonists of pathogenic bacteria in these cultures. As a first step, the ability of seven strains of BPI to grow in extracellular products of I. galbana was evaluated, with positive results with four of these (334, C33, 11 and 77). Subsequently, the effect of the addition of these strains on the growth of I. galbana was evaluated. Comparison of growth rates of I. galbana with and without the addition of BPI showed no significant differences (P > 0.05). A stable and persistent inhibitory capacity of strain C33 on the pathogen Vibrio anguillarum was also observed. Finally, studies were made on the ingestion of BPI by larvae of Argopecten purpuratus (Lamarck 1819). Results demonstrated a significant ingestion of strain 11 (P > 0.05), when it was inoculated directly into the water, and bacterium C33, when delivered in conjunction with the microalga. Upon evaluating incorporation and maintenance of BPI strains 11 and C33 after 5 days of larval culture, we observed the major presence of strain C33 (3 × 102 cfu/larva) compared with strain 11 (90 cfu/larva). The results obtained suggested that it was feasible to use microalgal cultures as vectors for the introduction of bacterial antagonists to bacterial pathogens in molluscan larval culture.

Respiration and feeding of the surf clam Paphies donacina from New Zealand

Oxygen uptake and feeding (clearance) rates were measured for the tuatua Pahpies donacina from an exposed sand beach characterised by variable levels of productivity (4–12 μg l−1chlorophyll a) and an annual temperature range between 8 and 19 °C. The aims of the study were to assess the ability of the surf clam to regulate feeding activity and oxygen uptake over a range of food concentrations and temperature conditions. Tuatuas, shell length 27–95 mm, were exposed to temperatures of 10, 15 and 20 °C in summer and 5, 10 and 15 °C in winter. Aquatic oxygen uptake depended on both body weight and exposure temperature with body weight explaining the majority of the variation in the multiple-regression equation. Weight specific oxygen uptake was similar at the two upper temperatures and significantly reduced at the lower temperature. For a standard length tuatua the oxygen uptake was similar at 10 °C in both summer and winter. Clearance rates of P. donacina feeding on laboratory cultures of Isochrysis galbana were low compared with other bivalves. They increased logarithmically with cell concentration up to a maximal rate, then declined at higher cell levels. The clearance rate depended upon shell length and dry tissue weight and was higher for tuatua acclimated at 10 °C than at 15 °C. It was concluded that P. donacina shows seasonal adjustment in oxygen uptake and filtration rate to compensate for seasonal temperature variation in the habitat. The 10 °C temperature optima for the clearance rate is consistent with the southern distribution of this species allowing it to feed effectively during periods of high food availability.

Variation of fatty acid profile with solar cycle in outdoor chemostat culture ofIsochrysis galbana ALII-4

Outdoor chemostat cultures of the marine microalgaIsochrysis galbana at constant dilution rate (0.034 h−1 ) have been carried out under different weather conditions. Steady-state biomass concentrations were 1.61±0.03 kg m−3 in May and 0.95±0.04 kg m−3 in July, resulting in biomass output rates of 0.54 kg m−3 d−1 and 0.32 kg m−3 d−1 in May and July, respectively. Two patterns of daily variation with the solar cycle were observed in the fatty acid content. Saturated and mono-unsaturated fatty acids (16:0 and 16:1n7) show significant variation with the solar cycle, associated with short-term changes in environmental factors. Palmitic and palmitoleic acids are generated during daylight and consumed during the dark period. However, polyunsaturated fatty acids do not show a significant response to the solar cycle and their changes are associated with long-term variation in environmental factors. The maximum EPA productivity was obtained in May, 14.1 g m−3 d−1, which is close to that found in the literature for indoor continuous cultures. Nonetheless, the outdoor EPA content (up to 2.61 % d.wt) was lower than the indoor EPA content from a previous study (5% d.wt).

Relationships between photopigments, cell carbon, cell nitrogen and growth rate for a marine nanoflagellate

Ammonium-limited batch cultures of Isochrysis galbana were grown in both continuous light and 12-h light-dark cycles. The maximum observed specific growth rate (measured in terms of cell numbers) was similar under both illumination regimes, but the mean cell content of Chl a was higher in intermittent illumination. The N:C ratio of the culture was linearly related to relative specific growth rate. A highly correlated linear relationship was found between carotenoid and C, with a similar slope for both light regimes. In contrast, Chl a was linearly correlated with N, but the slope of the relationship changed with illumination and the coefficients of variation were higher. The Chl a:C ratio depended on nutritional state and on the illumination regime.

Biomass production and biochemical composition in mass cultures of the marine microalga Isochrysis galbana Parke at varying nutrient concentrations

Mass cultures of Isochrysis galbana were carried out with four nutrient concentrations ranging from 2 to 16 m M of NaNO 3 and salinity 35‰. An air flow of 15 l/min maintained a CO 2 transference rate sufficient to keep the pH below 8.4. Using these conditions, equations were calculated by a multiple non-linear least squares regression of order four, enabling predictions to be made of growth kinetics and chemical composition. Maximum cellular density of 65.5 × 10 6 cells/ml was obtained with 4 m M NaNO 3. Cellular volume was constant in the different nutrient concentrations. Protein content reached a maximum value of 374 μg/ml at 4 m M of NaNO 3, and this concentration also presented the maximum efficiency of transformation from nitrate to protein, i.e. 114%. As a result, lowest costs for harvesting are obtained at a nutrient concentration of 4 m M NaNO 3. Efficiencies decreased to 15% as nutrient concentration increased. Maximum values of chlorophyll a (21.9 μg/ml) and carbohydrates (213 μg/ml) were also obtained with 4 m M NaNO 3. In the logarithmic phase, the contents of protein, chlorophyll a, carbohydrates, RNA and DNA per cell were constant. Chlorophyll a reached values between 0.15 and 0.33 pg/cell in the stationary phase. Carbohydrate levels reached the maximum value of 3.16 pg/cell with 4 m M NaNO 3 in the stationary phase. The levels of RNA/cell and DNA/cell were constant in all the nutrient concentrations tested and in both growth phases, and ranged from 1.15 to 1.71 pg/cell for RNA and from 0.006 to 0.014 pg/cell for DNA. Growth in mass cultures is closely coupled to changes in nutrient concentrations and variations occur in protein, chlorophyll a and carbohydrate contents, showing differences of 177%, 220% and 136%, respectively, in the stationary phase. This biochemical variability, mainly in protein content, must have a marked effect on the nutritive value of this microalga as a feed in mariculture.

The effect of Brachionus plicatilis grown on three different species of phytoplankton on the ultrastructure of the hepatocytes of Chanos chanos (Forskål) fry

The effect of the rotifer, Brachionus plicatilis, grown on unialgal cultures of Isochrysis galbana, Tetraselmis sp. and Chlorella sp. on the hepatocytes of milkfish fry was evaluated by electron microscopy. Rotifers grown on the three different species of phytoplankton brought about different ultrastructural features in milkfish fry hepatocytes. Best results were obtained from fry reared on Isochrysis-fed rotifers. The use of marine Chlorella-fed rotifers as feed for fry resulted in the poorest hepatocyte ultrastructure, indicating that this was nutritionally the least adequate cultured food. None of the three diets, however, produced an optimal hepatocyte ultrastructure similar to that obtained by feeding the fry with a mixture of artificial feed and newly hatched Artemia nauplii.

Laboratory culture of the larvae of Conus textile Linné (Gastropoda: Toxoglossa)

The larvae of the Indo-Pacific gastropod Conns textile Linné were reared in the laboratory from hatching through metamorphosis. Larvae fed a mixed phytoplankton culture of Isochrysis galbana and Phaeodactylum tricornutum grew at a rate of 0.06 mm/day and began metamorphosing 16 days after hatching. Unfed control cultures yielded no metamorphically competent larvae. Laboratory-reared larvae metamorphosed spontaneously on the walls of the fïberglass rearing tanks when their average shell length was 1.5 mm. Measurements made on field-collected Conns textile juveniles indicate that the larvae metamorphose at the same size in the laboratory as they do in nature. Rates of larval shell length increase and dry weight increase paralleled each other until metamorphosis. At this point, shell growth slowed while dry weight increased suddenly. It is suggested that this weight increase reflects calcification and strengthening of the fragile larval shell upon entering the benthic environment.