RESUMEN

Marine thraustochytrids produce metabolically important lipids such as the long-chain omega-3 polyunsaturated fatty acids, carotenoids, and sterols. The growth and lipid production in thraustochytrids depends on the composition of the culture medium that often contains yeast extract as a source of amino acids. This work discusses the effects of individual amino acids provided in the culture medium as the only source of nitrogen, on the production of biomass and lipids by the thraustochytrid Thraustochytrium sp. RT2316-16. A reconstructed metabolic network based on the annotated genome of RT2316-16 in combination with flux balance analysis was used to explain the observed growth and consumption of the nutrients. The culture kinetic parameters estimated from the experimental data were used to constrain the flux via the nutrient consumption rates and the specific growth rate of the triacylglycerol-free biomass in the genome-scale metabolic model (GEM) to predict the specific rate of ATP production for cell maintenance. A relationship was identified between the specific rate of ATP production for maintenance and the specific rate of glucose consumption. The GEM and the derived relationship for the production of ATP for maintenance were used in linear optimization problems, to successfully predict the specific growth rate of RT2316-16 in different experimental conditions.

Asunto(s)

Modelos Biológicos , Estramenopilos , Estramenopilos/metabolismo , Estramenopilos/genética , Medios de Cultivo/química , Medios de Cultivo/metabolismo , Redes y Vías Metabólicas/genética , Aminoácidos/metabolismo , Biomasa , Metabolismo de los Lípidos , Nutrientes/metabolismo , Adenosina Trifosfato/metabolismo

RESUMEN

Squalene is a widely distributed natural triterpene, as it is a key precursor in the biosynthesis of all sterols. It is a compound of high commercial value worldwide because it has nutritional, medicinal, pharmaceutical, and cosmetic applications, due to its different biological properties. The main source of extraction has been shark liver oil, which is currently unviable on a larger scale due to the impacts of overexploitation. Secondary sources are mainly vegetable oils, although a limited one, as they allow low productive yields. Due to the diversity of applications that squalene presents and its growing demand, there is an increasing interest in identifying sustainable sources of extraction. Wild species of thraustochytrids, which are heterotrophic protists, have been identified to have the highest squalene content compared to bacteria, yeasts, microalgae, and vegetable sources. Several studies have been carried out to identify the bioprocess conditions and regulation factors, such as the use of eustressors that promote an increase in the production of this triterpene; however, studies focused on optimizing their productive yields are still in its infancy. This review includes the current trends that also comprises the advances in genetic regulations in these microorganisms, with a view to identify the culture conditions that have been favorable in increasing the production of squalene, and the influences that both bioprocess conditions and applied regulation factors partake at a metabolic level.

Asunto(s)

Escualeno , Estramenopilos , Escualeno/metabolismo , Aceites de Plantas , Estramenopilos/genética , Estramenopilos/metabolismo , Esteroles

RESUMEN

The psychrophilic marine microorganism Thraustochytrium sp. RT2316-16 can produce carotenoids as well as lipids containing the omega-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid and docosahexaenoic acid. This work reports on the effects of the composition of the culture medium, including certain amino acids, on growth and lipid synthesis by RT2316-16. Compared with the culture on glutamate, the use of lysine, alanine, or serine, increased the content of the omega-3 PUFA in total lipids. In the media that contained yeast extract, glutamate, and glucose, lipid accumulation occurred when organic ammonium was exhausted earlier than glucose. In contrast, lipid mobilization was promoted if glucose was exhausted while organic ammonium (supplied by yeast extract and glutamate) remained in the medium. The total content of carotenoids in the lipid-free biomass decreased during the first 12 to 24 h of culture, simultaneously with a decrease in the total lipid content of the biomass. The experimental data suggested a possible interrelationship between the metabolism of carotenoids and lipids. A high content of omega-3 PUFA in the total lipids could be obtained by growing the thraustochytrid in a medium with a low glucose concentration (6 g L-1) and a high concentration of organic nitrogen (yeast extract 12 g L-1; glutamate 1.06 g L-1), after glucose was exhausted. These observations may guide the development of a strategy to enhance omega-3 PUFA in the biomass.

Asunto(s)

Ácidos Grasos Omega-3 , Estramenopilos , Nitrógeno/metabolismo , Ácidos Grasos Omega-3/metabolismo , Ácidos Docosahexaenoicos/metabolismo , Ácido Eicosapentaenoico/metabolismo , Estramenopilos/metabolismo , Carotenoides/metabolismo , Glucosa/metabolismo , Glutamatos/metabolismo , Ácidos Grasos/metabolismo

RESUMEN

Production of biomass and lipids in batch cultures of the Antarctic thraustochytrid Oblongichytrium sp. RT2316-13, is reported. The microorganism proved capable of producing nearly 67% docosahexaenoic acid (DHA) and 15% eicosapentaenoic acid (EPA) in its total lipid fraction. Biomass with a maximum total lipid content of 33.5% (wt/wt) could be produced at 15°C in batch culture using a medium containing glucose (20 g/L), yeast extract (10.5 g/L), and other minor components. A lower culture temperature (5°C) reduced biomass and lipid productivities compared to culture at 15°C, but enhanced the DHA and EPA content of the lipids by 6.4- and 3.3-fold, respectively. Both a simple minimally structured mathematical model and a more complex genome-scale metabolic model (GEM) allowed the fermentation profiles in batch cultures to be satisfactorily simulated, but the GEM provided much greater insight in the biochemical and physiological phenomena underlying the observed behavior. Unlike the simpler model, the GEM could be interrogated for the possible effects of various external factors such as oxygen supply, on the expected outcomes. In silico predictions of oxygen effects were consistent with literature observations for DHA producing thraustochytrids.

Asunto(s)

Organismos Acuáticos/metabolismo , Biotecnología/métodos , Medios de Cultivo/química , Ácidos Docosahexaenoicos/metabolismo , Ácido Eicosapentaenoico/metabolismo , Fermentación , Estramenopilos/metabolismo , Regiones Antárticas , Organismos Acuáticos/crecimiento & desarrollo , Organismos Acuáticos/aislamiento & purificación , Biomasa , Frío , Ácidos Docosahexaenoicos/análisis , Ácido Eicosapentaenoico/análisis , Estramenopilos/crecimiento & desarrollo , Estramenopilos/aislamiento & purificación

RESUMEN

Thraustochytrids have been isolated from different aquatic systems; however, few studies have reported their occurrence in Antarctica. In this study, 13 strains close to strains belonging to the genera Oblongichytrium, Thraustochytrium, and Aurantiochytrium were isolated from seawater samples collected near the Antarctic Base Professor Julio Escudero (S 62°12'57' E 58°57'35″). Docosahexaenoic acid (DHA) was found in the total lipids of all the isolates; DHA content of the biomass (dry weight) varied between 3.3 and 33 mg/g under the growth conditions for isolation. Five of the Antarctic thraustochytrids were able to accumulate lipids at levels higher than 20% w/w. Two strains, RT2316-7 and RT2316-13, were selected to test the effect of the incubation temperature (at 5°C for 14 days and at 15°C for 5 days). Incubation temperature had little effect on the lipid content and biomass yield; however, its effect on the fatty acid composition was significant (p < .05). The low incubation temperature favored the accumulation of eicosapentaenoic acid (EPA), palmitic acid and stearic acid in the total lipids of RT2316-7. Percentage of EPA, DHA and the omega-6 fatty acid dihomo-γ-linolenic acid of total fatty acids of RT2316-13 was higher at the low incubation temperature. RT2316-13 accumulated the highest lipid content (30.0 ± 0.5%) with a carbon to nitrogen mass ratio equal to 16.9. On the contrary, lipid accumulation in RT2316-7 occurred at high concentration of the nitrogen sources (monosodium glutamate or yeast extract). The capability to accumulate lipids with a fatty acid profile that can be tuned through cultivation temperature make the Antarctic thraustochytrid RT2316-13 a candidate for the production of lipids with different uses.

Asunto(s)

Reactores Biológicos/microbiología , Ácidos Grasos Omega-3/biosíntesis , Estramenopilos/metabolismo , Ácido 8,11,14-Eicosatrienoico/análisis , Regiones Antárticas , Membrana Celular/fisiología , Ácidos Docosahexaenoicos/análisis , Ácido Eicosapentaenoico/análisis , Ácido Palmítico/análisis , Agua de Mar , Ácidos Esteáricos/análisis , Estramenopilos/clasificación , Estramenopilos/crecimiento & desarrollo , Estramenopilos/aislamiento & purificación , Temperatura

RESUMEN

Total lipids and docosahexaenoic acid (DHA) production by a Chilean isolated thraustochytrid were evaluated under different growth conditions in shake flasks. The analyzed strain was identified as Thraustochytrium striatum according to an 18S rRNA gene sequence analysis. The strain (T. striatum AL16) showed negligible growth in media prepared with artificial seawater at concentrations lower than 50% v/v and pH lower than 5. Maltose and starch were better carbon sources for growth than glucose. DHA content of the biomass grown with maltose (60 g L-1) was doubled by increasing the agitation rate from 150 to 250 rpm. The DHA (0.8-6%) and eicosapentaenoic acid (0.2-21%) content in the total lipids varied depending on culture conditions and culture age. Lipid and DHA concentration increased (up to 5 g L-1 and 66 mg L-1, respectively) by regularly feeding the culture with a concentrated starch solution. Carotenoid accumulation was detected in cells grown with maltose or starch. Contrasting conditions of starch and glucose cultures were selected for comparative proteomics. Total protein extracts were separated by two-dimensional gel electrophoresis; 25 spots were identified using ESI-MS/MS. A protein database (143,006 entries) for proteomic interrogation was generated using de novo assembling of Thraustochytrium sp. LLF1b - MMETSP0199_2 transcriptome; 18 proteins differentially expressed were identified. Three ATP synthases were differentially accumulated in cultures with glucose, whereas malate dehydrogenase was more abundant in cells cultured with starch.

Asunto(s)

Proteínas Algáceas/genética , Medios de Cultivo/farmacología , Ácidos Docosahexaenoicos/biosíntesis , Ácido Eicosapentaenoico/biosíntesis , Proteoma/genética , Estramenopilos/efectos de los fármacos , Proteínas Algáceas/clasificación , Proteínas Algáceas/aislamiento & purificación , Biomasa , Carotenoides/biosíntesis , Carotenoides/aislamiento & purificación , Medios de Cultivo/química , Ácidos Docosahexaenoicos/aislamiento & purificación , Ácido Eicosapentaenoico/aislamiento & purificación , Expresión Génica , Ontología de Genes , Glucosa/metabolismo , Glucosa/farmacología , Concentración de Iones de Hidrógeno , Maltosa/metabolismo , Maltosa/farmacología , Anotación de Secuencia Molecular , Proteoma/clasificación , Proteoma/aislamiento & purificación , ARN Ribosómico 18S/genética , Agua de Mar/química , Análisis de Secuencia de ADN , Almidón/metabolismo , Almidón/farmacología , Estramenopilos/genética , Estramenopilos/crecimiento & desarrollo , Estramenopilos/metabolismo

RESUMEN

Alanine mother liquor, a type of industrial waste from alanine fermentation, was used as a nitrogen source to produce docosahexaenoic acid (DHA) by Schizochytrium sp. B4D1. The results indicated that yeast extract could trigger the utilization of the alanine mother liquor. Additionally, the alanine can be quenched during the culture, which aids in DHA accumulation. The medium components were optimized via response surface methodology as follows: 99.98-g/L glucose, 0.05-g/L yeast extract and a 183.17 dilution factor of the alanine mother liquid (v/v, with an alanine content of 0.72 g/L) and 17.98% inoculum concentration (v/v). Finally, in a 50-mL shake-flask fermentation, the DHA yield was 2.29 g/L.

Asunto(s)

Ácidos Docosahexaenoicos/biosíntesis , Alanina/metabolismo , Estramenopilos/metabolismo , Levaduras , Péptidos y Proteínas de Señalización Intercelular/aislamiento & purificación , Alanina/análisis , Fermentación , Glucosa , Residuos Industriales

RESUMEN

The production of biofuels from microalgae is a promising and sustainable alternative. Its production is determined by the content of lipids and carbohydrates, which is different for each microalgae species and is affected by environmental factors, being lighting one of the principal determining their biochemical composition. The colour temperature (electromagnetic radiation and light spectrum) is a determining factor for the production of lipids and carbohydrates in microalgae. The aim of this assay was to evaluate the effect of three colour temperatures (6500, 10,000 and 20,000 °K) on the biomass (cel mL-1), biomass production and productivity (g L-1 and g L-1 day-1), lipid and carbohydrate content (%), lipid and carbohydrate production and productivity (mg L-1 and mg L-1 day-1), composition and content of fatty acids (%) in two microalgae species: Dunaliella salina and Nannochloropsis oculata. The highest cell density was observed for N. oculata in stationary phase in the control (83.93 × 106 cel mL-1). However, higher lipid content was obtained in D. salina in stationary phase at 10,000 °K (80%), while N. oculata showed 67% at 6500 °K. The highest carbohydrate content was 25% in stationary phase for D. salina at 20,000 °K. Regarding the production of lipids, D. salina reached a maximum of 523 mg L-1 in exponential phase at 6500 and 10,000 °K. The highest carbohydrate production was 38 mg L-1 for D. salina in exponential phase at 20,000 °K. In both microalgae, 15 different fatty acids were identified; the most abundant was palmitic acid with 35.8% for N. oculata in stationary phase at 10,000 °K, while D. salina showed 67% of polyunsaturated fatty acids in exponential phase at 6500 °K. In conclusion, the ideal colour temperature for microalgae culture to obtain biofuels should be based on the biomolecule of interest, being necessary to individually evaluate for each species.

Asunto(s)

Carbohidratos/biosíntesis , Lípidos/biosíntesis , Microalgas/metabolismo , Estramenopilos/metabolismo , Biocombustibles , Biomasa , Color , Ácidos Grasos/análisis , Iluminación , Especificidad de la Especie , Temperatura

RESUMEN

ABSTRACT Thraustochytrids are unicellular protists belonging to the Labyrinthulomycetes class, which are characterized by the presence of a high lipid content that could replace conventional fatty acids. They show a wide geographic distribution, however their diversity in the Antarctic Region is rather scarce. The analysis based on the complete sequence of 18S rRNA gene showed that strain 34-2 belongs to the species Thraustochytrium kinnei, with 99% identity. The total lipid profile shows a wide range of saturated fatty acids with abundance of palmitic acid (16:0), showing a range of 16.1-19.7%. On the other hand, long-chain polyunsaturated fatty acids, mainly docosahexaenoic acid and eicosapentaenoic acid are present in a range of 24-48% and 6.1-9.3%, respectively. All factors analyzed in cells (biomass, carbon consumption and lipid content) changed with variations of culture temperature (10 °C and 25 °C). The growth in glucose at a temperature of 10 °C presented the most favorable conditions to produce omega-3fatty acid. This research provides the identification and characterization of a Thraustochytrids strain, with a total lipid content that presents potential applications in the production of nutritional supplements and as well biofuels.

Asunto(s)

Agua de Mar/microbiología , Ácidos Grasos/metabolismo , Estramenopilos/metabolismo , Filogenia , Biotecnología , Ácidos Grasos/química , Estramenopilos/aislamiento & purificación , Estramenopilos/clasificación , Estramenopilos/genética , Regiones Antárticas

RESUMEN

Background: Mutation breeding is one of the most important routes to achieving high docosahexaenoic acid (DHA) productivity using Schizochytrium. However, few selection strategies have been reported that aim to generate a high DHA content in Schizochytrium lipids. Results: First, culture temperature altered the butanol tolerance of Schizochytrium limacinum B4D1. Second, S. limacinum E8 was obtained by selecting mutants with high butanol tolerance. This mutant exhibited a 17.97% lower proportion of DHA than the parent strain S. limacinum B4D1. Third, a negative selection strategy was designed in which S. limacinum F6, a mutant with poor butanol tolerance, was obtained. The proportion of DHA in S. limacinum F6 was 11.22% higher than that of parent strain S. limacinum B4D1. Finally, the performances of S. limacinum B4D1, E8 and F6 were compared. These three strains had different fatty acid profiles, but there was no statistical difference in their biomasses and lipid yields. Conclusion: It was feasible to identified the relative DHA content of S. limacinum mutants based on their butanol tolerance.

Asunto(s)

Ácidos Docosahexaenoicos/biosíntesis , Butanoles/metabolismo , Estramenopilos/genética , Estramenopilos/metabolismo , Selección Genética , Temperatura , Ácido Eicosapentaenoico/metabolismo , Biomasa , Butanoles/toxicidad , Ácidos Grasos/metabolismo , Ácidos Grasos/química , Estramenopilos/efectos de los fármacos , Fermentación , Mutación

RESUMEN

BACKGROUND: Nannochloropsis salina (= Eustigmatophyceae) is a marine microalga which has become a biotechnological target because of its high capacity to produce polyunsaturated fatty acids and triacylglycerols. It has been used as a source of biofuel, pigments and food supplements, like Omega 3. Only some Nannochloropsis species have been sequenced, but none of them benefit from a genome-scale metabolic model (GSMM), able to predict its metabolic capabilities. RESULTS: We present iNS934, the first GSMM for N. salina, including 2345 reactions, 934 genes and an exhaustive description of lipid and nitrogen metabolism. iNS934 has a 90% of accuracy when making simple growth/no-growth predictions and has a 15% error rate in predicting growth rates in different experimental conditions. Moreover, iNS934 allowed us to propose 82 different knockout strategies for strain optimization of triacylglycerols. CONCLUSIONS: iNS934 provides a powerful tool for metabolic improvement, allowing predictions and simulations of N. salina metabolism under different media and genetic conditions. It also provides a systemic view of N. salina metabolism, potentially guiding research and providing context to -omics data.

Asunto(s)

Genómica , Lípidos/biosíntesis , Microalgas/genética , Microalgas/metabolismo , Modelos Biológicos , Estramenopilos/genética , Estramenopilos/metabolismo , Mapeo Cromosómico , Perfilación de la Expresión Génica , Ingeniería Genética , Anotación de Secuencia Molecular , Nitrógeno/metabolismo

RESUMEN

Thraustochytrids are unicellular protists belonging to the Labyrinthulomycetes class, which are characterized by the presence of a high lipid content that could replace conventional fatty acids. They show a wide geographic distribution, however their diversity in the Antarctic Region is rather scarce. The analysis based on the complete sequence of 18S rRNA gene showed that strain 34-2 belongs to the species Thraustochytrium kinnei, with 99% identity. The total lipid profile shows a wide range of saturated fatty acids with abundance of palmitic acid (16:0), showing a range of 16.1-19.7%. On the other hand, long-chain polyunsaturated fatty acids, mainly docosahexaenoic acid and eicosapentaenoic acid are present in a range of 24-48% and 6.1-9.3%, respectively. All factors analyzed in cells (biomass, carbon consumption and lipid content) changed with variations of culture temperature (10°C and 25°C). The growth in glucose at a temperature of 10°C presented the most favorable conditions to produce omega-3fatty acid. This research provides the identification and characterization of a Thraustochytrids strain, with a total lipid content that presents potential applications in the production of nutritional supplements and as well biofuels.

Asunto(s)

Ácidos Grasos/metabolismo , Agua de Mar/microbiología , Estramenopilos/metabolismo , Regiones Antárticas , Biotecnología , Ácidos Grasos/química , Filogenia , Estramenopilos/clasificación , Estramenopilos/genética , Estramenopilos/aislamiento & purificación

RESUMEN

Abstract The high costs and environmental concerns associated with using marine resources as sources of oils rich in polyunsaturated fatty acids have prompted searches for alternative sources of such oils. Some microorganisms, among them members of the genus Aurantiochytrium, can synthesize large amounts of these biocompounds. However, various parameters that affect the polyunsaturated fatty acids production of these organisms, such as the carbon and nitrogen sources supplied during their cultivation, require further elucidation. The objective of this investigation was to study the effect of different concentrations of carbon and total nitrogen on the production of polyunsaturated fatty acids, particularly docosahexaenoic acid, by Aurantiochytrium sp. ATCC PRA-276. We performed batch system experiments using an initial glucose concentration of 30 g/L and three different concentrations of total nitrogen, including 3.0, 0.44, and 0.22 g/L, and fed-batch system experiments in which 0.14 g/L of glucose and 0.0014 g/L of total nitrogen were supplied hourly. To assess the effects of these different treatments, we determined the biomass, glucose, total nitrogen and polyunsaturated fatty acids concentration. The maximum cell concentration (23.9 g/L) was obtained after 96 h of cultivation in the batch system using initial concentrations of 0.22 g/L total nitrogen and 30 g/L glucose. Under these conditions, we observed the highest level of polyunsaturated fatty acids production (3.6 g/L), with docosahexaenoic acid and docosapentaenoic acid ω6 concentrations reaching 2.54 and 0.80 g/L, respectively.

Asunto(s)

Carbono/metabolismo , Ácidos Docosahexaenoicos/metabolismo , Estramenopilos/metabolismo , Nitrógeno/metabolismo , Biomasa , Medios de Cultivo/química , Estramenopilos/crecimiento & desarrollo

RESUMEN

The high costs and environmental concerns associated with using marine resources as sources of oils rich in polyunsaturated fatty acids have prompted searches for alternative sources of such oils. Some microorganisms, among them members of the genus Aurantiochytrium, can synthesize large amounts of these biocompounds. However, various parameters that affect the polyunsaturated fatty acids production of these organisms, such as the carbon and nitrogen sources supplied during their cultivation, require further elucidation. The objective of this investigation was to study the effect of different concentrations of carbon and total nitrogen on the production of polyunsaturated fatty acids, particularly docosahexaenoic acid, by Aurantiochytrium sp. ATCC PRA-276. We performed batch system experiments using an initial glucose concentration of 30g/L and three different concentrations of total nitrogen, including 3.0, 0.44, and 0.22g/L, and fed-batch system experiments in which 0.14g/L of glucose and 0.0014g/L of total nitrogen were supplied hourly. To assess the effects of these different treatments, we determined the biomass, glucose, total nitrogen and polyunsaturated fatty acids concentration. The maximum cell concentration (23.9g/L) was obtained after 96h of cultivation in the batch system using initial concentrations of 0.22g/L total nitrogen and 30g/L glucose. Under these conditions, we observed the highest level of polyunsaturated fatty acids production (3.6g/L), with docosahexaenoic acid and docosapentaenoic acid ω6 concentrations reaching 2.54 and 0.80g/L, respectively.

Asunto(s)

Carbono/metabolismo , Ácidos Docosahexaenoicos/metabolismo , Nitrógeno/metabolismo , Estramenopilos/metabolismo , Biomasa , Medios de Cultivo/química , Estramenopilos/crecimiento & desarrollo

RESUMEN

Two-stage cultivation for microalgae biomass is a promising strategy to boost lipid accumulation and productivity. Most of the currently described processes use energy-intensive centrifugation for cell separation after the first cultivation stage. This laboratory study evaluated alkaline flocculation as low-cost alternative separation method to harvest Nannochloropsis oculata prior to cultivation in the second nutrient-depleted cultivation stage. Biomass concentration over time and the maximum quantum yield of photosystem II expressed as Fv:Fm ratio showed identical patterns for both harvesting methods in both stages. The composition of total lipids, carbohydrates, and protein was similar for biomass harvested via alkaline flocculation or centrifugation. Likewise, both harvest methods yielded the same increase in total lipid content, to 40% within the first 2days of the nutrient-depleted stage, with an enrichment in C16 fatty acid methyl esters. Centrifugation can therefore be replaced with alkaline flocculation to harvest Nannochloropsis oculata after the first cultivation stage.

Asunto(s)

Biotecnología/métodos , Lípidos/biosíntesis , Microalgas/metabolismo , Estramenopilos/metabolismo , Biomasa , Centrifugación , Ácidos Grasos/química , Ácidos Grasos/metabolismo , Floculación , Lípidos/química , Microalgas/crecimiento & desarrollo , Complejo de Proteína del Fotosistema II/metabolismo , Estramenopilos/crecimiento & desarrollo

RESUMEN

The effect of sequential batch cultures of the marine microalgae Nannochloropsis oculata on lipid and biomass production was studied in 200-L raceway ponds for 167 days (nine harvesting cycles) during winter and spring seasons under greenhouse conditions. The highest biomass concentration and productivity were 1.2 g/L and 49.8 mg/L/day on days 73 (5th cycle) and 167 (9th cycle), respectively. The overall interval of lipid production was between 131 and 530 mg/L. Despite the daily and seasonal variations of light irradiance (0-1099 µmol photon/m2 s), greenhouse temperature (2.1-50.7 °C), and culture temperature (12.5-31.4 °C), ANOVA analysis showed no statistical difference (p value > 0.01) on the fatty acid methyl ester (FAMES) composition over the nine harvesting cycles evaluated. The most abundant FAMES were palmitic (C16:0), stearic (C18:0) and palmitoleic (C16:1∆9) acids with 37.1, 28.6, and 8.4 %, respectively. The sequential batch cultures of N. oculata in raceway ponds showed an increasing biomass production in each new cycle while keeping the quality of the fatty acid mixture under daily and seasonal variations of light irradiance and temperature.

Asunto(s)

Biomasa , Ácidos Grasos/análisis , Metabolismo de los Lípidos , Microalgas/metabolismo , Estramenopilos/metabolismo , Estanques , Estaciones del Año

RESUMEN

Muitas drogas terapêuticas produzidas pela indústria farmacêutica são estruturas químicas isoladas de organismos encontrados na natureza ou moléculas baseadas nelas. Podem ser incluídas nesse grupo drogas isoladas de organismos marinhos, como corais, esponjas e algas marinhas, conhecidos como produtores de grandes quantidades de metabólitos secundários. Com base neste fato o presente estudo teve como objetivo realizar a prospecção de moléculas bioativas com propósito farmacológico, em extratos de algas marinhas vermelhas (Rhodophyta) e pardas (Heterokontophyta) coletadas no litoral brasileiro. A prospecção foi realizada por meio de avaliação de seus potenciais antioxidante, antibacteriano, antifúngico, anticancerígeno, e antiparasitário contra organismos causadores de leishmaniose e esquistossomose. Para as avaliações foram empregadas os extratos supercríticos de 5 espécies diferentes, sendo 2 pardas: Dictyota dichotoma e D. menstrualis e três vermelhas: Chondria littoralis, Spyridia hypnoides e Plocamium brasiliense. Os extratos foram avaliados quanto aos seus potenciais bioativos e os resultados mais promissores foram selecionados para as etapas seguintes do fracionamento. Em uma avaliação geral os extratos apresentaram bons resultados e representam uma potencial fonte de bioativos. Os extratos das espécies de D. dichotoma e D. menstrualis foram então submetidos a um procedimento de fracionamento bioguiado pela atividade esquistossomicida. Incorporou-se ainda um terceiro extrato de D. mertensii aos estudos e todas as etapas do fracionamento foram monitoradas por LC-MS. Comparando-se as massas detectadas em todas as frações que apresentaram atividade, para os 3 extratos, foi verificado que a substância de m/z 271,24 estava presente em todas elas, portanto os procedimentos de isolamento foram direcionados a esta molécula para a qual foi possível isolar 7 mg. Diferentemente do que era esperado a molécula quando avaliada isoladamente não apresentou atividade esquistossomicida, levando a hipótese de que a atividade seja decorrente de uma molécula diferente para cada espécie ou ainda que a mesma seja decorrente de uma interação com outras substâncias por um mecanismo de ação aditivo ou sinérgico. O trabalho avaliado de forma geral apresentou resultados promissores e representa um grande embasamento para servir como base para posteriores trabalho de fracionamento

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Several therapeutic drugs manufactured by the pharmaceutical industry are chemical structures isolated from organisms that are found in nature or molecules based on that. May be included at this group drugs isolated from marine organisms, like corals, sponges and seaweeds, known as great secondary metabolites producers. Based on this facts the objective of the present study is to perform a prospection study to achieve bioactive molecules with pharmaceutical purposes, on extracts made from red (Rhodophyta) and brown (Heterokontophyta) seaweed collected in the Brazilian shore. The prospection studies was performed by means of evaluation of the antioxidant, antibacterial, antifungal, anticancer and antiparasitic (against Leishmania and Schistosoma) potential. In the evaluation were tested the supercritical extracts of 5 different species, including 2 brown species: Dictyota dichotoma and D. menstrualis and 3 red species: Chondria littoralis, Spyridia hypnoides and Plocamium brasiliense. The extracts were evaluated by their potential bioactive compounds and the most promising results were selected for the following fractionation steps. Overall the extracts have shown good results and may be represent a potential source of bioactive molecules. The extracts of both D. dichotoma and D. menstrualis were submitted to a bioguided fractionation process by their antischistosomal activities. It was still included a third extract from D. mertensii to the studies and every step was monitored by LC-MS techniques. Comparing the detected mass for each active fraction, it was observed the presence of a substance with m/z 271,24 in all of the extracts, so the isolating procedures were directed to obtain that specific molecule, which was obtained in a biomass of 7 mg. Differently than expected the molecule when evaluated isolated do not show the antischistosomal activity, leading to the hypothesis that the activity was related to different molecules for each species or even the observed effect is resulted by an interaction mechanism with another substances by an additive or synergist mechanism. The overall evaluation of the whole work show some promising results and it represent a great support for future fractionation works

Asunto(s)

Farmacología , Algas Marinas , Citotoxicidad Inmunológica , Rhodophyta/metabolismo , Biomarcadores Farmacológicos/metabolismo , Estramenopilos/metabolismo , Productos Biológicos/administración & dosificación , Cromatografía con Fluido Supercrítico

RESUMEN

The chemical screening carried out on Schizochytrium sp. biomass led the identification of 24 types of organic compounds belonging to n-alkanes, 1-alkenes, 1-alkanols, free fatty acids, methyl and ethyl esters of saturated and unsaturated fatty acids, saturated tri- and diglycerides, unsaturated monoglycerides, wax esters, sterols, triterpenes, and mono- and sesquiterpenes. Moreover, a sample containing fully saturated ethyl biodiesel was obtained experimentally with a yield of 28.72% w/w of the crude extract, and an average chain length of 15.52 carbons. This strain produced no toxins, but showed important nutrients, making it potentially applicable to the field of functional food, and biodiesel production.

Asunto(s)

Biocombustibles , Metaboloma , Compuestos Orgánicos/análisis , Estramenopilos/química , Estramenopilos/metabolismo , Cromatografía de Gases y Espectrometría de Masas

RESUMEN

The chemical screening carried out on Schizochytrium sp. biomass led the identification of 24 types of organic compounds belonging to n-alkanes, 1-alkenes, 1-alkanols, free fatty acids, methyl and ethyl esters of saturated and unsaturated fatty acids, saturated tri- and diglycerides, unsaturated monoglycerides, wax esters, sterols, triterpenes, and mono- and sesquiterpenes. Moreover, a sample containing fully saturated ethyl biodiesel was obtained experimentally with a yield of 28.72% w/w of the crude extract, and an average chain length of 15.52 carbons. This strain produced no toxins, but showed important nutrients, making it potentially applicable to the field of functional food, and biodiesel production.

Asunto(s)

Biocombustibles , Metaboloma , Compuestos Orgánicos/análisis , Estramenopilos/química , Estramenopilos/metabolismo , Cromatografía de Gases y Espectrometría de Masas

RESUMEN

The chemical screening carried out on Schizochytrium sp. biomass led the identification of 24 types of organic compounds belonging to n-alkanes, 1-alkenes, 1-alkanols, free fatty acids, methyl and ethyl esters of saturated and unsaturated fatty acids, saturated tri- and diglycerides, unsaturated monoglycerides, wax esters, sterols, triterpenes, and mono- and sesquiterpenes. Moreover, a sample containing fully saturated ethyl biodiesel was obtained experimentally with a yield of 28.72% w/w of the crude extract, and an average chain length of 15.52 carbons. This strain produced no toxins, but showed important nutrients, making it potentially applicable to the field of functional food, and biodiesel production.

Asunto(s)

Biocombustibles , Metaboloma , Compuestos Orgánicos/análisis , Estramenopilos/química , Estramenopilos/metabolismo , Cromatografía de Gases y Espectrometría de Masas