Aplicaciones farmacéuticas e impactos ambientales de la Spirulina (Arthrospira). Una visión general

Recently, microalgae cultivation for different applications, including the production of nutritional and pharmaceutical active compounds has received increasing attention. Among the different genera, Spirulina (Arthrospira sp.) is one of the most promising blue-green microalgae (Cyanophyta) because it is rich in antioxidants, essential amino acids (EAAs), minerals, proteins, polyunsaturated fatty acids and vitamins. It has a high protein content (60-70% of the dry weight), which is a complete protein, i.e. containing all EAAs. Therefore, Spirulina is currently a commercial product with high nutritional value and also a significant source of complementary and alternative medicine. The objective of the present work was to review the pharmaceutical and therapeutic applications of Spirulina, especially its antioxidant, anti-inflammatory, anti-cancer, anti-microbial, anti-diabetic, anti-obesity and anti-toxicity properties. The results were obtained from experiments in the literature performed in vitro and in vivo using experimental animals. The main reported active ingredients in Spirulina include phycocyanin, tocopherol, β-carotene, caffeic acids and chlorogenic acid, which showed individual or synergetic effects. In addition, the present review discusses the future perspectives of genetically modified Spirulina as a source for industrial products while producing valuable biomass photoautotrophically. Furthermore, the consequent environmental impacts of large-scale cultivation of Spirulina are discussed.Recientemente, el cultivo de microalgas para diferentes aplicaciones, incluida la producción de compuestos activos nutricionales y farmacéuticos, está recibiendo una atención cada vez mayor. Entre los diferentes géneros, Spirulina (Arthrospira sp.) es una de las microalgas azul-verde más prometedoras (Cyanophyta) porque es rica en antioxidantes, aminoácidos esenciales (EAAs), minerales, proteínas, ácidos grasos poliinsaturados y vitaminas. Tiene un alto contenido de proteína (60-70% del peso seco) es una proteína completa, es decir, contiene todos los EAAs. Por lo tanto, la Spirulina es actualmente un producto comercial con alto valor nutricional y también una fuente importante parala medicina complementaria y alternativa. El objetivo del presente trabajo es revisar las aplicaciones farmacéuticas y terapéuticas de Spirulina, especialmente propiedades antioxidantes, antiinflamatorias, anticancerígenas, antimicrobianas, antidiabéticas, antiobesidad y antitóxicas. Los resultados se obtienen a partir de trabajos experimentales realizados in vitro e in vivo utilizando animales de experimentación. Los principales ingredientes activos reportados en Spirulina incluyen ficocianina, tocoferol, β-caroteno, ácidos caféicos y clorogénico que mostraron efectos individuales o sinérgicos. Además, en la presente revisión se discute las perspectivas futuras de la Spirulina genéticamente modificada como fuente de productos industriales, al mismo tiempo que se produce una valiosa biomasa fotoautotrófica. Además, se discutieron los impactos ambientales consiguientes del cultivo a gran escala de la Spirulina

Induction of the synthesis of bioactive compounds of the marine alga Tetraselmis tetrathele (West) Butcher grown under salinity stress

This work aims at the induction of the synthesis bioactive compounds in microalgae which are used in aquacultures. Experiments were done using Tetraselmis tetrathele in batch culture for 8 days under different salinity levels. The growth of the alga at salinity 20 ppm was increased by fivefold and synthesis of carotenoids by 20-fold in comparison to the controlled. Increasing NaCl concentration resulted in increasing the fatty acid accumulation in T. tetrathele cells. Saturated fatty acids were the main constituent in the fatty acid methyl esters (FAMEs) (3.48 mg/g) at salinity 25 ppm. The predominated fatty acids were tridecylic, myristic and pentadecanoic which have potential antimicrobial activities. GC–MS analyses of the alga acetone extract grown under different NaCl concentrations were established. The results showed the presence of 18 bioactive compounds: 9-octadecenamide; in addition to the different esters of some fatty acids: hexanedioic, 1,2-cyclohexanedicarboxylic, phthalic, oleanitrile, hexanedioic and 1,2-cyclohexanedicarboxylic (71.5%; 64.9%; 55.4%; 49.6%; 18.7%; 25.2% and 14.5%, respectively). The study suggested that the alga biosynthesized various bioactive compounds under different salinity levels as defense mechanisms. Accordingly, the growth of T. tetrathele under salinity stress before being used in aquacultures is recommended

Effect of salt stress on antioxidant system and the metabolism of the reactive oxygen species in Dunaliella salina and Dunaliella tertiolecta

The physiological and biochemical adaptations of two chlorophytes Dunaliella salina and Dunaliella tertiolecta developed to extreme saline environment were assessed in the present study. Both Dunaliella cultures were treated with a range of NaCl concentrations ranging from 0.05 to 4 M NaCl and the influence of salinity on growth and antioxidant parameters were determined. Biomass yields, chlorophyll and carbohydrate contents were reduced at salinity extremes. Protein contents were elevated under low salinities. No evidence or for large change was found in soluble amino acids during salinity stress. Osmoregulation is mediated by glycerol as compatible solute in both Dunaliella species. The maximum glycerol production was observed at high growth salinities. Under hyposaline conditions, a low content of β-carotene was noticed, whereas hypersaline conditions induced an increase in this product, about 1.4 and 1.1-fold more than its value at optimum salinities for D. salina and D. tertiolecta, respectively. An exposure to 0.5, 0.1, and 4 M NaCl increased H2O2 contents were positively correlated with the level of thiobarbituric acid reactive substances. The levels of six antioxidant enzymes (superoxide dismutase, catalase, peroxidase, ascorbate peroidase, glutathione reductase and glutathione S-transferase) and two antioxidant substrates (glutathione and ascorbic acid) were quantified. The data revealed a differential response between D. salina and D. tertiolecta in response to different salinity levels. The involvement of oxidative stress at various salinity levels is implied by the alterations in antioxidant enzymes and substrates, but the specific changes are very different between hypo and hypersaline stress conditions.Key words: Antioxidant system, β-carotene, Dunaliella, glycerol, reactive oxygen species, salt stress

Antimicrobial activity of some seaweeds species from Red sea, against multidrug resistant bacteria

This study evaluates the antibacterial activity of diethyl ether, methanol, ethanol and chloroform extracts of red algae Ceramium rubrum (Rhodophyta), Sargassum vulgare, Sargassum fusiforme and Padina pavonia (Phaeophyta) collected from Red sea, Egypt. The algal extracts were tested for their antibacterial activity against ten multidrug resistant clinical isolates of Gram positive and Gram negative bacteria. The highest inhibition activity among all extracts was obtained with 100 μl diethyl ether extract S. fusiforme against Staphylococcus aureus 2 and 50 μl ethanol extract of S. vulgare against Klebsiella pneumoniae. The algal extract of S. fusiforme and S. vulgare was characterized by Gas chromatography–mass spectrometry (GC–MS). The compounds with antimicrobial activity were identified, such as phenols, terpenes, acetogenins, indoles, fatty acids and volatile halogenated hydrocarbons. Transmission electron microscopy was applied for determining the morphological changes in S. aureus 2 and K. pneumonia treated with 100 μl diethyl ether extract of S. fusiforme and 50 μl ethanol extract of S. vulgare, respectively. Perforation of cell wall, leakage of cytoplasmic contents, severe distortion of outer cell shape, inner chromatin mild scattered cytoplasmic vacuolation, rupture of cell wall, and decreased cell size for both bacterial isolates treated with 100 μl diethyl ether of S. fusiforme extract and 50 μl S. vulgare ethanolic extract were recorded

Effect of temperature on growth and fatty acids profile of the biodiesel producing microalga Scenedesmus acutus

Description of the subject. The present study examined the effect of temperature (15, 20, 25, 30, 35 and 40 °C) on biomass, esterified fatty acids content and fatty acid productivity of Scenedesmus acutus. Objectives. This work aimed to study the effect of variation in temperature on lipid productivity and fatty acid profiles of S. acutus as a feedstock for biodiesel production. Method. The alga was grown under different temperatures and its biomass, as well as fatty acid content and composition, were determined. Results. The maximum growth rate of S. acutus was achieved at 30 °C , but there was no significant difference in biomass productivity at 25 and 30 °C (0.41 and 0.42 g·l-1·d-1), respectively. The highest fatty acid content (104.1 mg·g-1 CDW) was recorded at low temperature (15 °C) and decreased with increasing temperature. As a result of high biomass production, fatty acids productivity showed the highest values (41.27 and 42.10 mg·l-1·d-1) at 25 and 30 °C, respectively. The proportion of saturated and mono-unsaturated fatty acids increased from 13.72 to 23.79% and from 11.13 to 33.10% of total fatty acids when the incubation temperature was raised from 15 to 40 °C, respectively. The increase of temperature from 15 to 40 °C decreased the poly-unsaturated fatty acids from 75.15% to 43.10% of total fatty acids, respectively. Conclusions. The present study concluded that incubation temperature was a critical parameter for quantitative and qualitative fatty acid compositions of S. acutus. In addition, the type and proportion of individual fatty acids, which interfere with biodiesel quality, can be modified using different incubation temperatures in order to meet the biodiesel international standards

Seaweed extracts as biological control of aflatoxins produced by Aspergillus parasiticus and Aspergillus flavus

Abstract Background Mycotoxins are secondary metabolites made by a variety of molds and fungi. They contaminate a lot of food products and local crops during pre- and post-harvesting under favorable conditions like high temperature and moisture. Aspergillus species are the most common fungi that contaminate food and produce biochemicals known as mycotoxins. Aflatoxins (AFB1, AFB2, AFG1, and AFG2) are the major mycotoxins produced by A. flavus and A. parasiticus that harm animal and human health. These fungi are controlled by chemical fungicides, but these are harmful to the environment. The aim of this study was to determine whether the aflatoxigenic fungi can be exterminated only by marine algal extracts or not. Results The findings showed that the tested seaweed extracts inhibited fungal growth and aflatoxins production to varying degrees. The maximum antifungal activity was recorded in Halimeda opuntia extract against A. parasiticus-24 and A. flavus-18 and Turbunaria decurrens extract against A. flavus-18 (with an inhibition percentage of 77.78%), followed by Jania rubens extract against A. parasiticus-16 with inhibition percentage 75.88% compared to the control. Aqueous extract of H. opuntia effectively eliminated aflatoxins (B1, B2, G1, and G2) in A. parasiticus-16 and A. parasiticus-24. T. decurrens extract could detoxify 100% of aflatoxins in three isolates of A. parasiticus. J. rubens extract eliminated aflatoxins in A. parasiticus-15 and A. parasiticus-16 compared to their normal production using high-performance liquid chromatography. Conclusions According to this study, the macroalgal species with numerous distinctive antifungal properties constituents significantly inhibited the growth and production of aflatoxin in A. parasiticus and A. flavus isolates. The findings supported the use of macroalgae as a biological control agent against fungi and their toxins

A Review of Microalgae- and Cyanobacteria-Based Biodegradation of Organic Pollutants

This review proposes a new bioremediation method based on the diverse functionalities of algae. A greenway for cleansing wastewater is more ecologically friendly and environmentally sustainable than prior methods with other bacteria. New bioremediation technology employing algae and cyanobacteria for the removal of a wide range of organic contaminants is reasonable and has great potential. The prevalence of organic contaminants in aquatic habitats may endanger the health and well-being of several marine creatures. Agriculture, industry, and household trash are just a few of the human-caused sources of organic pollutants that contaminate waterways around the world. Before wastewater can be released into waterways, it must be cleaned. Algae-based wastewater treatment systems are becoming increasingly popular because of their environmental sustainability and lack of secondary pollutants. According to the kind of pollutant, the physicochemical properties of wastewater, and the algal species, algae and cyanobacteria can absorb and accumulate a wide spectrum of organic pollutants at different rates. In addition, phytoremediation is a cost-effective alternative to conventional treatments for degrading organic contaminants. Phycoremediationally produced algal biomass may also be an important part of the bioenergy value chain. This article focuses on microalgae and cyanobacteria species, which may remove many organic contaminants from water systems

Enhancement of Biochemical and Nutritional Contents of Some Cultivated Seaweeds Under Laboratory Conditions

<p>Six species of macroalgae belonging to the Chlorophyta, Phaeophyta, and Rhodophyta divisions were cultivated in a closed system with Guillard's f/2, Walne's, Provasoli Enriched Seawater (PES) medium, and seawater (control) for 6 weeks. The growth rate and parameters of the tested seaweeds showed that all used media enhanced the growth rate and chemical content as compared with other seaweeds cultivated in seawater without addition of any nutrients. There are significant differences in the effect of the used media on the seaweed composition at <i>p</i> = .01; PES is more effective than the f/2 and Walne's media. The results indicate that the cultivation technique of some macroalgae was an efficient tool for increasing the seaweeds' biomass and increasing their chemical compounds, calories, and energy under laboratory conditions.</p

Therapeutic Uses of Red Macroalgae

Red Seaweed &ldquo;Rhodophyta&rdquo; are an important group of macroalgae that include approximately 7000 species. They are a rich source of structurally diverse bioactive constituents, including protein, sulfated polysaccharides, pigments, polyunsaturated fatty acids, vitamins, minerals, and phenolic compounds with nutritional, medical, and industrial importance. Polysaccharides are the main components in the cell wall of red algae and represent about 40&ndash;50% of the dry weight, which are extensively utilized in industry and pharmaceutical compounds, due to their thickening and gelling properties. The hydrocolloids galactans carrageenans and agars are the main red seaweed cell wall polysaccharides, which had broad-spectrum therapeutic characters. Generally, the chemical contents of seaweed are different according to the algal species, growth stage, environment, and external conditions, e.g., the temperature of the water, light intensity, nutrient concentrations in the ecosystem. Economically, they can be recommended as a substitute source for natural ingredients that contribute to a broad range of bioactivities like cancer therapy, anti-inflammatory agents, and acetylcholinesterase inhibitory. This review touches on the main points of the pharmaceutical applications of red seaweed, as well as the exploitation of their specific compounds and secondary metabolites with vital roles