Spirulina platensis aqueous extracts ameliorate colonic mucosal damage and modulate gut microbiota disorder in mice with ulcerative colitis by inhibiting inflammation and oxidative stress / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Ulcerative colitis (UC) is a chronic and recurrent inflammatory bowel disease (IBD) that has become a major gastroenterologic problem during recent decades. Numerous complicating factors are involved in UC development such as oxidative stress, inflammation, and microbiota disorder. These factors exacerbate damage to the intestinal mucosal barrier. Spirulina platensis is a commercial alga with various biological activity that is widely used as a functional ingredient in food and beverage products. However, there have been few studies on the treatment of UC using S. platensis aqueous extracts (SP), and the underlying mechanism of action of SP against UC has not yet been elucidated. Herein, we aimed to investigate the modulatory effect of SP on microbiota disorders in UC mice and clarify the underlying mechanisms by which SP alleviates damage to the intestinal mucosal barrier. Dextran sulfate sodium (DSS) was used to establish a normal human colonic epithelial cell (NCM460) injury model and UC animal model. The mitochondrial membrane potential assay 3-‍‍(4,5-dimethylthiazol-2-yl)-2,‍5-diphenyltetrazolium bromide (MTT) and staining with Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) and Hoechst 33258 were carried out to determine the effects of SP on the NCM460 cell injury model. Moreover, hematoxylin and eosin (H&E) staining, transmission electron microscopy (TEM), enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qPCR), western blot, and 16S ribosomal DNA (rDNA) sequencing were used to explore the effects and underlying mechanisms of action of SP on UC in C57BL/6 mice. In vitro studies showed that SP alleviated DSS-induced NCM460 cell injury. SP also significantly reduced the excessive generation of intracellular reactive oxygen species (ROS) and prevented mitochondrial membrane potential reduction after DSS challenge. In vivo studies indicated that SP administration could alleviate the severity of DSS-induced colonic mucosal damage compared with the control group. Inhibition of inflammation and oxidative stress was associated with increases in the activity of antioxidant enzymes and the expression of tight junction proteins (TJs) post-SP treatment. SP improved gut microbiota disorder mainly by increasing antioxidant enzyme activity and the expression of TJs in the colon. Our findings demonstrate that the protective effect of SP against UC is based on its inhibition of pro-inflammatory cytokine overproduction, inhibition of DSS-induced ROS production, and enhanced expression of antioxidant enzymes and TJs in the colonic mucosal barrier.

Spirulina platensis en el tratamiento de la obesidad y de algunas de sus consecuencias / Spirulina platensis in the Treatment of Obesity and some of its Consequences

Introducción: La Spirulina platensis constituye un sustancial reservorio de nutrientes y de alimentos funcionales con un bajo contenido de calorías. Aunque en la literatura se mencionan varias cualidades benéficas, una de ellas es aumentar la sensación de saciedad, lo que abre la posibilidad de ser empleada en la prevención y tratamiento de la obesidad y de algunas de sus consecuencias. Objetivo: Describir el papel de la Spirulina platensis en el tratamiento de la obesidad y de algunas de sus consecuencias. Métodos: Se realizó una búsqueda de literatura relevante sobre el tema en el primer cuatrimestre de 2020. Se utilizaron como buscadores de información científica: Pubmed, Scielo, Google y Google Académico. La estrategia de búsqueda incluyó los siguientes términos como palabras clave: Espirulina; Spirulina platensis; Obesidad; Exceso de peso. Se evaluaron artículos de revisión, de investigación y páginas Web que, en general, tenían menos de 10 años de publicados, en idioma español, portugués e inglés, y que hicieran referencia específicamente al tema de estudio a través del título. Fueron excluidos los artículos que no cumplieron con estas condiciones. Esto permitió el estudio de 75 referencias bibliográficas, de las cuales 51 se citaron en el presente artículo. Conclusiones: La Spirulina platensis representa una opción como suplemento nutraceútico y funcional, con valor preventivo y coadyuvante en el tratamiento de la obesidad y de algunas de sus consecuencias, al menos a corto plazo(AU)

Introduction: Spirulina platensis is a substantial reservoir of functional foods and nutrients with low calorie content. Although several beneficial qualities are mentioned in the scientific literature, one of them is to increase the feeling of satiety, which opens the possibility of being used for preventing and treating obesity, as well as some of its consequences. Objective: To describe the role of Spirulina platensis for treating obesity and some of its consequences. Methods: A search of relevant literature on the subject was carried out in the first four months of 2020. The following scientific information search engines were used: Pubmed, Scielo, Google and Google Scholar. The search strategy included the following terms as keywords: espirulina [spirulina], Spirulina platensis, obesidad [obesity], exceso de peso [overweight]. Review articles, research articles and Web pages were assessed, which, in general, had been published within less than ten years, in Spanish, Portuguese and English, and which made specific reference to the study topic through their titles. Articles that did not meet these conditions were excluded. This allowed the study of 75 bibliographic references, of which 51 were cited in this article. Conclusions: Spirulina platensis is an option as a nutraceutical and functional supplement, with preventive and coadjutant value for the treatment of obesity and some of its consequences, at least in the short term(AU)

Espirulina como producto natural con potencialidades para su empleo en pacientes con diabetes mellitus / Spirulina as a natural product with potentials for its use in patients with diabetes mellitus

Introducción: La Spirulina platensis es una cianobacteria planctónica filamentosa, que contiene un espectro natural de mezclas de pigmentos de caroteno, xantofila y ficocianina, con actividad antioxidante y la posibilidad de inducir un mejor control de la glucemia en las personas con diabetes mellitus. Objetivo: Describir los efectos del uso del producto logrado a partir de la bacteria Spirulina platensis en el paciente con diabetes mellitus. Método: Se utilizaron como buscadores de información científica a PubMed, SciELO, Google y Google Académico. Las palabras claves utilizadas fueron: espirulina, Spirulina platensis, Arthrospira platensis, diabetes mellitus y control metabólico. Se evaluaron artículos de revisión, de investigación y páginas web que, en general, tenían menos de 10 años de publicados en idioma español, portugués e inglés, cuyos títulos estaban relacionados con el tema de estudio. Se obtuvieron 70 referencias bibliográficas, de las cuales 49 se citaron en el presente artículo. Conclusiones: La espirulina tiene varios efectos benéficos que permiten su uso como coadyuvante en la prevención y tratamiento de la diabetes mellitus. Es un nutriente con bondades nutraceúticas y funcionales, con potente actividad antioxidante, que incide en un mejor control glucémico y puede ser útil en el manejo de las posibles complicaciones y comorbilidades que acompañan a la diabetes mellitus. Su uso conlleva la posibilidad de algunas reacciones adversas, sobre todo de tipo digestivas, aunque no son frecuentes si se emplean las dosis recomendadas; en general, es considerada un producto seguro(AU)

Introduction: Spirulina platensis is a plankton filamentous cyanobacteria that has a natural spectrum of carotene, xanthophyll and phycocyanin pigments´mix, with antioxidant activity and the possibility of inducing a better control of glycemia in patients with diabetes mellitus. Objective: Describe the effects of the use in patients with diabetes mellitus of a product made from Spirulina platensis bacteria. Method: There were used as scientific information searchers: PubMed, SciELO, Google and Google Scholar. The keywords used were: Spirulina, Spirulina platensis, Arthrospira platensis, diabetes mellitus and metabolic control. There were assessed review articles, research articles and web pages, that in general had less than 10 years of being published in Spanish, Portuguese or English language, and whose titles were related with the studied topic. 70 bibliographic references were collected, and 49 of them were quoted in this article. Conclusions: Spirulina has different beneficial effects that allow its use as coadjuvant agent in the prevention and treatment of diabetes mellitus. It is a nutrient with functional and nutraceutical mildness, with a powerful antioxidant activity which has incidence in a better glycemic control and can be useful in the management of possible complications and comorbidities that accompany diabetes mellitus. Its use entails the possible adverse reactions, mainly digestive ones; although they are not frequent if the recommended doses are used. In general terms, it is considered a safe product(AU)

Antioxidant Activities of Phycocyanin: A Bioactive Compound from Spirulina platensis

Background and Objectives:The cyanobacterium Spirulinaalso calledblue green algae is a class of gram negative bacteria which possesses wide range of bioactive colored components as Phycocyanin, carotenoids and chlorophyll. Spirulinais one of the microalgae containing nutrients that havebeen used as a functional food in addition to therapeuticand pharmaceutical applications.This study aimed to evaluate the biochemical composition of Spirulina platensisbiomass and its ethanolic and aqueous extracts, as well as, evaluate the antioxidant activities of the biomass, ethanolic, aqueous and the purified Phycocyanin.Materials and Methods:The chemical compositions of Spirulina platensis were determined, as well as the antioxidant activity of extracts, Phycocyanin, Phycocyanopeptide and Phycocyanobilin using (DPPH) radical-scavenging activity.Results:Results show that biomass has higher total proteins (49.72±0.508%), total carbohydrates (10.3±0.330%), moisture content (7.5±0.685%), lipids (7.2±0.105%) and Minerals (6.9±0.130%).In biomass, the total phenols (51.20±0.25μg/mL) and flavonoids (97.73±1.858 μg/mL) were high compared to the ethanolic (49.48±0.130 and 69.07±1.814 μg/mL) and aqueous (15.27±0.639 and 4.67±0.611 μg/mL) extracts respectively. In the phenolic compounds, pyrogallol was identified as the major compound in biomass and aqueous extract (63.85 and 12.33%) respectively, E-vanillic acid in ethanolic (18.20 %), whereas, hespirdin (3.517 and1.639%) were major flavonoids found in aqueous and ethanolic extracts respectively. The DPPH scavenging activity was found higher in ethanolic extract compared to aqueous while in bioactive, the order of antioxidant activity was Phycocyanin > Phycocyanobilin > Phycocyanopeptide.Conclusions:The study data regarding toSpirulinanutritional value, makesSpirulinaan excellent choice when formulating diets and combating malnutrition. Furthermore, it is a strong antioxidant and could be used as alternative treatments as anticancer, antidiabetic, and anti-inflammatory agent.

Efficiency of chitosan and eggshell on harvesting of Spirulina sp. in a bioflocculation process

Aims@#Microalgae were very small in size (a few μm) and have a low concentration in the medium. Due to their size, harvesting of microalgae from their growth medium remain a major obstacle in downstream processing. Efficient harvesting method must be applied to ensure it is cost effective, preserves quality and improves the culture process which is important for commercial algal production. Common harvesting methods use to harvest microalgae from their growth medium are centrifugation, filtration, flotation, sedimentation, and flocculation. Flocculation is a common method use to harvest microalgae due to low cost, save time and highly efficient method for algae biomass recovery. The purpose of this study was to investigate the effects chitosan and eggshell on flocculation of microalga Spirulina platensis. Chitosan and eggshell were chosen as flocculant due to their biodegradability, non-toxicity and safe to handle. @*Methodology and results@#The efficiencies of flocculation process were examined by conducting experiments over a range of culture pH, flocculant concentrations and flocculation time using chitosan and eggshell as flocculant agent. Under optimized flocculation conditions of 50 mg/L chitosan at pH 8 culture media for 90 min of flocculation time and 4 mg/mL eggshell at pH 4 culture media for 8 min of flocculation time, the maximum flocculation efficiency obtained was 79.98±1.65% and 97.17±1.38%, respectively. @*Conclusion, significance and impact of study@#Therefore, it can be concluded that chitosan and eggshell could be used as flocculants for harvesting large scale microalgal biomass production. Nevertheless, eggshell is more economical and more efficient compared to chitosan in harvesting microalgae biomass.

Effect of Gamma Radiation on Growth and Metabolic Activities of Arthrospira platensis

This work aimed to study the influence of gamma radiation on the growth and production of some active substances of Arthrospira platensis. Biomass production was significantly inhibited (p ≤ 0.05) by 21 and 34%, with respect to the control at 2.0 and 2.5 kGy, respectively. Chlorophyll-a content showed 11% reduction at 2.5 kGy compared to the control. As a result of growth and Chl-a inhibition, chlorophyll productivity recorded a continuous significant decrease below the control in the cells exposed to 1, 1.5, 2 and 2.5 kGy by 8, 12, 15 and 25%, respectively after 15 days of incubation. In addition, phycobillins productivity showed significant decrease by 10 and 36% below the control at 2 and 2.5 kGy of gamma radiation, respectively. Protein production decreased significantly by 24% at 1.5 kGy; low doses of gamma irradiation (0.5, 1.0 and 1.5 kGy) induced carbohydrate production by 106, 246 and 146%, respectively. Lipid content increased significantly over the control at 0.5 kGy of gamma irradiation by 22%, which was decreased at higher doses. Interestingly, carotenoid productivity showed significant increase at all used gamma doses up to 155% over the control.

The immunoregulative action of polysacchrides of Spirulina platensis in peripheral blood mononuclear cells in patients with chronic hepatitis B virus infection / 中国药理学通报

Aim To investigate the immunoregulative action of polysacchrides of Spirulina platensis ( PSP ) on peripheral blood mononuclear cells ( PBMCs) in pa-tients with chronic hepatitis B virus infection. Meth-ods Proliferation and cycle of PBMCs from patients with chronic hepatitis B virus infection were measured by MTT colorimetry and flow cytometry respectively. The concentration of IFN-γ, IL-2 , IL-4 in supernatants of PBMCs were examined by ELISA. The mRNA ex-pression of IFN-γin PBMCs from patients with chronic hepatitis B virus infection was detected by RT-PCR. Results PSP could induce proliferation of PBMCs in patients with chronic hepatitis B virus infection. In ad-dition, PSP could increase the protein expression of IFN-γ and IL-2 in supernatants of PBMCs in patients with chronic hepatitis B virus infection, and PSP could also enhance the mRNA expression of IFN-γof PBMCs in patients with chronic hepatitis B virus infection. However, PSP inhibited the protein expression of IL-4 of PBMCs in patients with chronic hepatitis B virus in-fection. Conclusion PSP can promote the immune function and plays an important immunoregulation function on patients with chronic hepatitis B virus in-fection.

Influence of Spirulina platensis exudates on the endocrine and nervous systems of a mammalian model

Objective: To investigate the effect of intra-peritoneal injection of purified exudates of axenic Spirulina platensis on the mammalian endocrine and nervous systems. Methods: The intra-peritoneal injection of the cyanobacterial exudates in mice was applied. Sex hormonal levels of testosterone and progesterone were measured using radioimmunoassay while the follicular stimulating hormone and luteinizing hormone were evaluated by direct chemiluminescence. In addition, superoxide dismutase, catalase and glutathione peroxidase were monitored in the hippocampus region using spectrophotometric method. The levels of the hippocampal monoamines, dopamine, noradrenaline and serotonin were analyzed by high performance liquid chromatography while the acetyl choline neurotransmitter was measured by colorimetric method using choline/ acetylcholine assay kit. Results: A sharp disruption in the sex hormones levels of testosterone, progesterone, follicular stimulating hormone and luteinizing hormone was demonstrated in the serum of the treated mice. At the same time, a significant reduction in the endogenous antioxidant defense enzymes, superoxide dismutase, catalase and glutathione peroxidase was observed in the hippocampus region of the injected mice. Moreover, levels of dopamine, noradrenaline, serotonin and acetyl choline neurotransmitter in the same region were significantly affected as a result of the treatment with Spirulina filtrate. The gas chromatography- mass spectrometer and liquid chromatography mass spectrometry/mass spectrometry analysis showed the presence of some sterol-like compounds in the cyanobacterial filtrate. Conclusions: This study demonstrated the capability of Spirulina to release detrimental bioactive metabolites into their surrounding that can disrupt the mammalian endocrine and nervous systems.

A method to estimate the biomass of Spirulina platensis cultivated on a solid medium

This paper presents a method to estimate the biomass of Spirulina cultivated on solid medium with sugarcane bagasse as a support, in view of the difficulty in determining biomass concentrations in bioprocesses, particularly those conducted in semi-solid or solid media. The genus Spirulina of the family Oscillatoriaceae comprises the group of multicellular filamentous cyanobacteria (blue-green microalgae). Spirulina is used as fish feed in aquaculture, as a food supplement, a source of vitamins, pigments, antioxidants and fatty acids. Therefore, its growth parameters are extremely important in studies of the development and optimization of bioprocesses. For studies of biomass growth, Spirulina platensis was cultured on solid medium using sugarcane bagasse as a support. The biomass thus produced was estimated by determining the protein content of the material grown during the process, based on the ratio of dry weight to protein content obtained in the surface growth experiments. The protein content of the biomass grown in Erlenmeyer flasks on surface medium was examined daily to check the influence of culture time on the protein content of the biomass. The biomass showed an average protein content of 42.2%. This methodology enabled the concentration of biomass adhering to the sugarcane bagasse to be estimated from the indirect measurement of the protein content associated with cell growth.

Estudo do reaproveitamento de meio no cultivo de Arthrospira (Spirulina) platensis / Study of reuse of Arthrospira (Spirulina) platensis cultivation medium

Arthrosphira (Spirulina) platensis apresenta substâncias de interesse nas indústrias alimentícia, farmacêutica e cosmética. A produção industrial envolve uma quantidade muito grande de água e sua viabilidade deve contemplar o reuso do meio, visando uma diminuição de custos com nutrientes, bem como da poluição ambiental, tornando-se assim um processo sustentável. O presente trabalho teve como objetivo principal a avaliação do reaproveitamento do meio no cultivo de A. platensis usando tratamentos físico-químicos de floculação e adsorção. Para tanto, tal cianobactéria foi cultivada em fotobiorreator (FBR) tubular em processos de batelada alimentada e contínuo em intensidade luminosa de 120 µmol fótons m-2 s-1, sob controle de pH. Foram desenvolvidas técnicas de tratamento de meio de cultivo proveniente de processo descontínuo alimentado de A. platensis para a remoção de matéria orgânica (MO) e pigmentos (60 - 96 %), permitindo assim seu reuso em novos cultivos. A. platensis foi cultivada nos meios tratados utilizando frascos Erlenmeyer, com avaliação de parâmetros como concentração celular máxima (Xm), conteúdo de clorofila-a (Chl) e conteúdo de proteína na biomassa seca (PTN). No processo simultâneo de floculação e adsorção com carvão ativado em pó (CAP), foram testados dois agentes floculantes, cloreto férrico (F) e sulfato férrico (S) bem como diferentes tempos de contato. No processo simultâneo de floculação com F e adsorção com CAP, as condições ótimas foram: CAP = 24,4 mg L-1 e F = 20,3 mg L-1durante 30,4 min de tempo de contato; com obtenção de: Xm = 4893 ± 33 mg L-1, Chl = 24,3 ± 0,1 mg g-1, PTN = 36,1 ± 0,6 %. As condições ótimas de tratamento simultâneo de floculação com S e adsorção com CAP foram: CAP = 40,0 mg L-1 e S = 32,8 mg L-1 durante 36,1 min de tempo de contato, com obtenção de: Xm = 4863 ± 64 mg L-1, Chl = 24,5 ± 0,6 mg g-1, PTN = 60,1 ± 0,6 %. No processo sequencial de floculação com F seguido de adsorção com carvão ativado granulado (CAG), as condições ótimas foram atingidas com: CAG = 108,4 g e F = 10,0 mg L-1 durante 30,8 min de tempo de residência; obtendo-se: Xm = 3140 ± 77 mg L-1, Chl = 35,4 ± 0,2 mg g-1, PTN = 44,9 ± 0,0 %. Adicionalmente, os meios tratados nessas condições ótimas de cada tratamento, também foram testados em FBR tubulares, atingindo valores de Xm, Chl e PTN maiores do que os obtidos com meio padrão. Além disso, o processo simultâneo de cultivo celular em FBR tubulares e adsorção contínua do meio de cultivo exaurido em coluna de CAG removeu 51 - 79 % de MO e pigmentos. Foi demonstrado que uma proporção de 75 % de meio tratado no meio de alimentação não produz diminuição significativa de produtividade celular (PX) e os resultados foram: concentração celular em estado estacionário (Xs) de 1568 ± 15 mg L-1, PX = 941 mg L-1 d-1, PTN = 42,0 ± 0,6 %, com diminuição de 65 % no custo de meio de cultivo. Por fim, conclui-se que é viável a utilização de processos físico-químicos no tratamento de meio a ser reaproveitado no cultivo de A. platensis, inclusive em FBR tubulares, com apreciável incremento de clorofila-a e proteínas na biomassa obtida em meio tratado

Arthrospira (Spirulina) platensis have compounds of interest in the food, pharmaceutical and cosmetic industries. Industrial production involves high volumes of water and its viability should contemplate medium reuse, aiming to reduce not only nutrient costs, but also environmental pollution, thus becoming a sustainable process. This work had as main objective the evaluation of A. platensis culture medium reuse through the physicochemical treatments flocculation and adsorption. Thus, this cyanobacterium was cultivated in tubular photobioreactor (PBR) by fed-batch and continuous processes at light intensity 120 µmol photons m-2 s-1 under pH control. Treatment techniques were developed for culture medium from fed-batch process to properly removal of organic matter (OM) and pigments (60 - 96 %), thus allowing its reuse in new cultures. A. platensis was cultivated in treated medium using Erlenmeyer flasks, with the evaluation of parameters such as maximum cell concentration (Xm), chlorophyll content (Chl) and protein content in dry biomass (PTN). For simultaneous flocculation and adsorption with powdered activated carbon (PAC), two flocculants were used: ferric chloride (F) and ferric sulfate (S), as well as different contact times. In the simultaneous process of F flocculation and PAC adsorption, optimum conditions were: PAC = 24.4 mg L-1 and F = 20.3 mg L-1 for 30.4 min contact time; results were: Xm = 4893 ± 33 mg L-1, Chl = 24.3 ± 0.1 mg g-1, PTN = 36.1 ± 0.6 %. Optimal conditions in the simultaneous process of S flocculation and PAC adsorption were: PAC = 40.0 mg L-1 and S = 32.8 mg L-1 for 36.1 min contact time; results were: Xm = 4863 ± 64 mg L-1, Chl = 24.5 ± 0.6 mg g-1, PTN = 60.1 ± 0.6 %. In the sequential process of F flocculation followed by adsorption with granular activated carbon (GAC), optimal conditions were reached at GAC = 108.4 g and F = 10.0 mg L-1 for 30.8 min of residence time, at which Xm = 3140 ± 77 mg L-1, Chl = 35.4 ± 0.2 mg g-1 and PTNPTN = 44.9 ± 0.0 % were obtained. Moreover, medium treated at each optimal condition were also tested in tubular PBRs, reaching values of Xm, Chl and PTN higher than those obtained with standard medium. Furthermore, the simultaneous process of cell cultivation in tubular PBR and continuous adsorption of spent cultivation medium through GAC column removed 51 - 79 % of OM and pigments. It was showed that 75 % of treated medium in the feed medium does not cause significant decrease in cell productivity (PX) and results were: steady-state cell concentration (Xs) = 1568 ± 15 mg L-1, PX = 941 mg L-1 d-1, PTN = 42.0 ± 0.6 %, with 65 % reduction in medium price. At last, it can be inferred that the use of physicochemical processes in medium treatment is feasible for reuse in A. platensis cultivation, including that in tubular PBR, leading to considerable increase in chlorophyll and protein contents of the biomass obtained with treated medium

Antidepressant activity of spirulina platensis in experimentally induced dipression in mice.

The spray dried powder of Spirulina platensis was used to treatment of depression in different doses (100mg/kg, 200 mg/kg and 400 mg/kg) and Impramine (15mg/kg) as standard drug in experimental animal models like Forced swim test in mice, Tail suspension test in mice, Clonidine induced aggression behaviour in mice test, L-dopa induced hyper activity and aggressive behavior in mice, 5-HT induced head twitches in mice, From all the experimental model results were observed that the Spirulina platensis was possess the dose dependent anti depressant activity.

In vitro antiviral and antimicrobial activities of Spirulina platensis extract.

Spirulina platensis are filamentous, undifferentiated, non-toxigenic cyanobacteria that have been used as food since ancient times. There have been numerous studies on its antioxidant and antimicrobial actions. In this study antibacterial and antiviral effect of ethanol extract of Spirulina platensis were tested. The reduction of infectious viral units after treatment with ethanol extract of Spirulina platensis was tested. Non toxic doses of Spirulina platensis revealed 53.3%, 66.7%, 76.7%, 56.7%, and 50% reductions in vitro for infectious units of adenovirus type 7, Coxsackievirus B4, astrovirus type 1, rotavirus Wa strain, and adenovirus type 40 respectively. Using disc diffusion method to show the antibacterial effect of ethanol extract of Spirulina platensis against different bacterial strains (Escherichia coli, Staphylococcus aureus, Salmonella typhi, and Enterococcus faecalis) in addition to Candida albicans, inhibition zones were observed with Enterococcus faecalis and Candida albicans.

Aeration effect on Spirulina platensis growth and ã-linolenic acid production

The influence of aeration on algal growth and gamma-linolenic acid (GLA) production in a bubble column photobioreactor was investigated. Studies were performed in a 20-L reactor at different aeration rates (0.2-2.5 vvm). Static, continuous, and periodic operation of air resulted in 41.9%, 88.4%, and 108% air saturation of dissolved oxygen, for which the corresponding values of GLA were 2.3, 6.5, and 7.5 mg·g-1 dry cell weight, respectively. An increase in the aeration rate from 0.2 to 2.5 vvm enhanced both the specific growth rate and GLA content under periodic sparging in the bicarbonate medium. With a 6-fold increase in the aeration rate, the GLA content of the alga increased by 69.64% (5.6-9.5 mg· g-1 dry cell weight). In addition, the total fatty acid (TFA) content in dry biomass increased from 2.22% to 4.41%, whereas the algae maintained a constant GLA to TFA ratio within the aeration rate tested. The dependence of GLA production on the aeration rate was explained by interrelating the GLA production rate with the specific growth rate using the Luedeking and Piret mixed growth model.

Immunostimulant effects of dietary Spirulina platensis on tilapia Oreochromis niloticus.

Immuno-stimulant effects of the dietary Spirulina (Spirulina Platensis) were studied in tilapia, Oreochromis niloticus. For this purpose, fish were fed with Spirulina and the parameters of non-specific defense mechanisms, including serum bacterial activity, phagocytosis and lysozyme activity were performed 1. 2. 3 and 4 weeks after Spirulina administration. The efficacy also determined by bacterial challenge and monitoring specific antibody levels (Microagglutination). The results indicated that Spirulina enhanced responses of bactericidal, phagocytic activity and lysozyme activity. Determined by micro-agglutination, antiserum of experimental fish displayed high antibody titers. The fish fed with Spirulina and vaccinated fish conferred protection against Aeromonas hydrophila challenge 80% and 70% relative percentage survival (RPS) respectively. These findings suggest that dietary Spirulina has immunostimulatory effects on the immune system of tilapia (O. niloticus).

Spirulina platensis protects neurons via suppression of glial activation and peripheral sensitization leading to restoration of motor function in collagen-induced arthritic rats.

Spirulina platensis treatment (400 mg kg-1 for 25 days) effectively suppressed peripheral sensitization via modulation of glial activation and improved motor coordination and restoration of functional motor activity in collagen-induced arthritic rats. Spirulina treatment also resulted in an appreciable reduction of the NF200 accumulation in the spinal cord neurons of arthritic rats. This is indicative of neuroprotective action of S. platensis against glutamate excitotoxicity-induced central sensitization produced by the peripheral joint inflammation in the collagen-induced arthritis. The results suggest that effects of S. platensis may be due to its counter regulation of spinal glial activation and could be a potential strategy for the treatment of arthritis.

Growth and biopigment accumulation of cyanobacterium Spirulina platensis at different light intensities and temperature

In order to find out optimum culture condition for algal growth, the effect of light irradiance and temperature on growth rate, biomass composition and pigment production of Spirulina platensis were studied in axenic batch cultures. Growth kinetics of cultures showed a wide range of temperature tolerance from 20 ºC to 40 ºC. Maximum growth rate, cell production with maximum accumulation of chlorophyll and phycobilliproteins were found at temperature 35 ºC and 2,000 lux light intensity. But with further increase in temperature and light intensity, reduction in growth rate was observed. Carotenoid content was found maximum at 3,500 lux. Improvement in the carotenoid content with increase in light intensity is an adaptive mechanism of cyanobacterium S.platensis for photoprotection, could be a good basis for the exploitation of microalgae as a source of biopigments.

Growth and content of Spirulina platensis biomass chlorophyll cultivated at different values of light intensity and temperature using different nitrogen sources

The effects of light intensity and temperature in S. platensis cultivation with potassium nitrate or urea as nitrogen source were investigated, as well as the biomass chlorophyll contents of this cyanobacteria, through the Response Surface Methodology. Experiments were performed at temperatures from 25 to 34.5ºC and light intensities from 15 to 69 µmol photons m-2 s-1, in mineral medium. In cultivations with both sources of nitrogen, KNO3 and urea, statistic evaluation through multiple regression, no interactions of such independent variables were detected in the results of the dependent variables maximum cell concentration, chlorophyll biomass contents, cell and chlorophyll productivities, as well as in the nitrogen-cell conversion factor. In cultivation performed with both sources of nitrogen, it was possible to obtain satisfactory adjustments to relate the dependent variables to the independent variables. The best results were achieved at temperature of 30ºC, at light intensity of 60 µmol photons m-2s-1, for cell growth, with cell productivity of approximately 95 mg L-1 d-1 in cultivations with urea. For the chlorophyll biomass content, the most adequate light intensity was 24 µmol photons m-2 s-1.

Utilização do dióxido de carbono proveniente de fermentação alcoólica no cultivo de Spirulina (Arthrospira) platensis utilizando simultaneamente nitrato de sódio e sulfato de amônio como fontes de nitrogênio / Use of carbon dioxide from ethanol fermentation in Spirulina (Arthrospira) platensis cultivation using, simultaneously, ammonium sulfate and sodium nitrate as nitrogen sources

Arthrospira (Spirulina) platensis, cianobactéria fotoautotrófica, é importante comercialmente devido ao seu valor nutricional (elevado teor de proteínas, lipídios, vitaminas e minerais), além da presença do ácido graxo γ-linolênico e pigmentos, os quais agregam valor a esta biomassa. Este micro-organismo foi cultivado em fotobiorreator tubular, e os seguintes parâmetros foram avaliados: aplicação de diferentes sistemas de circulação de células, intensidades luminosas, adição simultânea de diferentes proporções de sulfato de amônio e nitrato de sódio como fontes de nitrogênio, adição de dióxido de carbono proveniente de fermentação alcoólica e, finalmente, a aplicação desta biomassa para remoção de metais pesados. Para a avaliação do sistema de circulação de células e da intensidade luminosa foram utilizadas as variáveis dependentes: concentração celular máxima (Xm), produtividade em células (Px), fator de conversão de nitrogênio em células (YX/N), eficiência fotossintética (EF) e teores de proteínas e lipídios da biomassa. Os protocolos de alimentação de nitrogênio e o uso de CO2 proveniente de cilindro ou de fermentação alcoólica foram avaliados com uso das mesmas variáveis já citadas, exceto EF; e, para remoção de Ni2+, Zn2+ e Pb2+ em solução aquosa foram estudados o tempo de adsorção e a influência da concentração inicial de metal em solução; com posterior cálculo da eficiência e capacidade de adsorção, e apresentação de modelos cinéticos e isotermas de equilíbrio. A melhor combinação de resultados em valores médios (Xm = 4055 mg L-1, Px = 406 mg L-1 d-1, YX/N = 5,07 mg mg-1, lipídios totais = 8,94%, proteínas totais = 30,3%, EF = 2,04%) foi obtida nos cultivos realizados com intensidade luminosa = 120 µ mol fótons m-2 s-1. O tipo de sistema de circulação de células utilizado não influenciou estatisticamente quase nenhuma das respostas estudadas e isto indica a possibilidade de substituição do sistema tradicional airlift pelos outros testados...

Arthrospira (Spirulina) platensis, photoautotrophic cyanobacterium, is commercially important due its high nutritional value (high content of proteins, lipids, vitamins, and minerals), besides of the presence of γ-linolenic fatty acids and pigments, which add value to this biomass. This microorganism was cultivated in tubular photobioreactor and the following parameters were evaluated: application of different cell circulation systems, light intensities, different protocols of simultaneous ammonium sulfate and sodium nitrate feeding, addition of CO2 from ethanol fermentation and, finally, the application of this biomass to the heavy metal removal. The dependent variables [maximum cell concentration (Xm), cell productivity (Px), nitrogen-to-cell conversion factor (YX/N), photosynthetic efficiency (EF) and proteins and lipids contents] were used to evaluate the influence of cell circulation systems and the light intensities. The nitrogen feeding protocols and the use of CO2 from cylinder or ethanol fermentation were evaluated using the same parameters aforementioned, except EF; and to analyze Ni2+, Zn2+ and Pb2+ removal, the adsorption time and the influence of initial metal concentration were evaluated with subsequent calculation of the efficiency and capacity adsorption. The kinetic models and equilibrium isotherms were also presented. The best combination of responses' mean values (Xm = 4055 mg L-1, Px = 406 mg L-1 d-1, YX/N = 5.07 mg mg-1, total lipids = 8.94%, total proteins = 30.3%, EF = 2.04%) was obtained at light intensity = 120 µ mol photons m-2 s-1. The cell circulation system did not exert statistical significant influence on almost all the responses, which suggests that the traditional airlift system could successfully be substituted by the others tested in this work. The mixture of the lower amount of nitrate in relation to ammonium (protocol I) (Xm = 4,543 g L-1; Px = 0,460 g L-1 d-1; YX/N = 15,6 g g-1; total lipids = 8,39% and total...

Cultivo contínuo de Arthrospira (Spirulina) platensis em fotobiorreator tubular utilizando uréia como fonte de nitrogênio e CO2 puro ou proveniente de fermentação alcoólica / Continuous cultivation of Arthrospira (Spirulina) platensis in tubular photobioreactor using urea as nitrogen source and CO2 from cylinder or produced by alcoholic fermentation

A aplicabilidade do processo de produção de microrganismos fotossintetizantes depende da obtenção de altas concentrações de biomassa e para isso seria interessante o emprego de fotobiorreatores tubulares. Eles permitem redução da área de cultivo e menor perda de CO2 e nitrogênio amoniacal por volatilização. Em uma primeira etapa deste trabalho, Arthrospira platensis foi cultivada por processo contínuo, avaliando-se diferentes valores de vazão específica de alimentação (D = 0,2 a 1,0 dia-1) e diferentes intensidades luminosas (I = 60 e 120 µmol fótons.m-2.s-1). Verificou-se que 120 µmol fótons.m-2.s-1 associada a D igual a 0,2 dia-1 resultou em maior valor de concentração celular em regime permanente (XP = 2446 ± 74 mg.L-1.d-1), mas o mesmo I associado a maior valor de D (0,6 dia-1) levou ao melhor valor de produtividade em células (PX = 938,73 mg.L-1.d-1). Foi possível a obtenção do regime permanente em quase todos os ensaios, o que indica que o cultivo contínuo de A. platensis em fotobiorreator tubular, usando uréia como fonte de nitrogênio, pode levar a resultados satisfatórios. Considerando a preocupação em relação à substituição de combustíveis fósseis por biocombustíveis, é iminente o crescente aumento da produção de etanol ainda nos próximos anos, e esse trabalho propõe o uso do CO2 liberado pela fermentação alcoólica na produção de microrganismos fotossintetizantes como A. platensis. Para isso, em uma segunda etapa, A. platensis foi cultivada por processo contínuo, com I igual a 120 µmol fótons.m-2.s-1, empregando uréia e CO2 proveniente de fermentação alcoólica para manutenção de pH e reposição da fonte de carbono. O uso desse CO2, sem tratamento prévio, associado a D igual a 0,6 dia-1 e concentração de uréia de 3,2 mM no meio de alimentação, permitiu a obtenção de PX igual a 839 ± 25 mg.L-1.d-1, o que está próximo de 938 ± 30mg.L-1.d-1, obtido com CO2 puro de cilindro. Estes resultados mostram que o uso de CO2 de fermentação alcoólica, associado a...

Appropriately designed tubular photobioreactors seem to be suitable for photosynthetic biomass production. It can reduce the cultivation area and provide lower loss of CO2 and ammoniacal nitrogen by volatilization. In a first step of this study, Arthrospira platensis was cultivated by continuous process, testing different values of dilution rate (D = 0.2 to 1.0 d-1) and light intensities (I = 60 and 120 µmol photons.m-2.s-1). The results of these runs showed that the maximum steady-state cell concentration (XS = 2446 ± 74 mg.L-1.d-1) was achieved at 120 µmol photons.m-2.s-1 and D of 0.2 d-1, but the same light intensity associated to higher dilution rate (0.6 d-1) provided the highest cell productivity (PX = 938 ± 30 mg.L-1.d-1), a value appreciably higher than that reported in other studies. Besides, steady-state conditions were achieved in most of the runs indicating that A. platensis continuous cultivation in the tubular photobioreactor, using urea as nitrogen source, can be performed effectively, thus appearing an interesting alternative for the large scale fixation of carbon dioxide to mitigate the green house effect. Taking into account the concern about the substitution of fossil fuel with biofuels, its evident that the ethanol production is going to increase even more in the next years, and this study propose the use of the CO2 released by the alcoholic fermentation for the production of photosynthetic microorganism such as A. platensis. For this purpose, in a second step, cultivations of A. platensis were carried out with 120 µmol photons.m-2.s-1 by continuous process, using urea and CO2 from Alcoholic fermentation for pH maintenance and carbon source replacement. The use of this CO2, without any treatment, associated with a D of 0.6 d-1 and feed urea concentration of 3.2 mM provide us a PX of 839 ± 25 mg.L-1.d-1, which is slightly lower than 938 ±30 mg.L-1.d-1, obtained with pure CO2 from cylinder. Our results showed that the use of CO2 from...

Avaliação da atividade antibacteriana da microalga Spirulina platensis / Assessment of the antibacterial activity of microalgae Spirulina platensis

Infecções são agravadas pelo aumento da resistência dos microrganismos a substâncias antimicrobianas. A necessidade de descoberta de novos medicamentos em decorrência desta resistência microbiana tem impulsionado o desenvolvimento de novas pesquisas. A Spirulina platensis, reconhecida pelas suas propriedades nutricionais, possui alta quantidade de compostos fenólicos, os quais podem apresentar também propriedades antimicrobianas. Objetivou-se cultivar a microalga Spirulina platensis, avaliar a produção de compostos fenólicos pela mesma, caracterizar a possível atividade antimicrobiana dos fenóis frente a Escherichia coli ATCC 25922, a Pseudomas aeruginosa ATCC 27853 e o Staphylococcus aureus ATCC 6538P e determinar a concentração inibitória mínima do extrato fenólico frente às bactérias citadas. Os resultados demonstraram que elevadas concentrações de nitrato de sódio (4g/L) no meio de cultivo não aumentaram a produção de compostos fenólicos. A microalga cultivada com 2 g/L de nitrato de sódio apresentou 2,13 mg/g de compostos fenólicos, sendo que os extratos apresentaram atividade antibacteriana contra o S. aureus, bactéria Grampositiva, com halo de inibição de 22 mm e 19 mm e concentração inibitória mínima de 47,46 mg/mL, indicando sua importância como potencial inibidor de S. aureus.

Bacterial infections are aggravated by the increasing resistance of microorganisms to antimicrobial substances. The need to discover new medicines to evade microbial resistance is the driving force behind much new research. The microalga Spirulina platensis, recognized for its nutritional properties, has a high content of phenolic compounds, which can provide antimicrobial properties. The objective of this study was to establish a culture of Spirulina platensis, estimate the production of phenolic compounds by this microalga, characterize the antimicrobial activity of the phenolics against microorganisms such as Escherichia coli ATCC 25922, Pseudomas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 6538P and determine the minimum inhibitory concentration (MIC) of the phenolic extract for these bacteria. It was found that adding high concentrations of sodium nitrate (4 g/L) to the medium did not increase the production of phenolic compounds. The microalgae grown with 2 g/L sodium nitrate produced 2.13 mg/g of phenolic compounds, and the extracts showed antibacterial activity against S. aureus, a Gram-positive bacterium, with inhibition haloes of 22 mm and 19 mm and a MIC of 47.46 mg/ mL, indicating its importance as a potential S. aureus inhibitor.