Hypocholesterolemic Effects of Nutraceuticals Produced from the Red Microalga Porphyridium sp in Rats

Red microalgae contain functional sulfated polysaccharides (containing dietary fibers), polyunsaturated fatty acids, zeaxanthin, vitamins, minerals, and proteins. Studies in rat models support the therapeutic properties of algal biomass and isolated polysaccharides. Algal products incorporated into rat diets were found to significantly improve total serum cholesterol, serum triglycerides, hepatic cholesterol levels, HDL/LDL ratios and increased fecal excretion of neutral sterols and bile acids. Morphological and metabolic changes were induced by consumption of algal products. These results suggest that red microalgae can be used as potent hypocholesterolemic agents, and they support the potential use of red microalgae as novel nutraceuticals

Changes in tannin and pectic substances at different positions within a bunch of Cavendish Banana (Musa cavendishii L. var. Montel) during development and maturation

Studies were carried out on changes in the tannin content, alcohol insoluble solids (AIS) and pectin fractions (water, ammonium oxalate and sodium hydroxide solubles) of Cavendish banana variety Montel at different positions within a bunch during maturation and ripening. There was a significant decrease (P<0.01) in the tannin content between the different portions of hands within a bunch and between different fingers within a hand during maturity. AIS increased at the early stages, but it decreased significantly (P< O. 05) in the ripe fruits (week 12). There was a significant difference (P<0.05) in the pectic substances at different positions within a bunch during maturity. The pectins increased at the early stages, reaching a maximum at week 12 and then slowly decreased. At the end of maturation, the pectic substances started to increase slowly until ripening. There were also significant differences (P<0.05) in the tannin content, AIS and pectic substances during maturity between different portions of hands and fingers. However, significant differences (P<0.05) were observed between portions of hands within a bunch and between fingers within a hand during maturity stage; the top hands and upper fingers were higher in tannin, AIS and pectic substances contents than the middle and bottom hands within a bunch and lower fingers within a hand respectively

Cell cycle of Chlorella vulgaris can deviate from the synchronous binary division model

Conditioned medium from high density Chlorella vugaris cultures was freeze dried extracted into ethanol. The ethanol was volatilized and the resulting powder then introduced with C. vulgaris photoautotrophic cultures which underwent asynchronous DNA replication forming cells with two, three, four, and six autospores instead of 2 n characteristic of synchronous DNA replication. These cells were blocked at the division stage of the cell cycle.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42355/1/10529_2004_Article_170565.pd

Chlorella vulgaris (Chlorellaceae) does not secrete autoinhibitors at high cell densities

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141950/1/ajb211559.pd

Estudos de atividade biológica do exopolissacarídeo e da biomassa da microalga porphydium cruentum

Porphyridium sp. é uma microalga que se encontra encapsulada dentro de um gel de exopolissacarídeos sulfatados (EPS). Os EPS’s possuem comportamentos de fluido dinâmico com produção de soluções altamente viscosas e de elevado peso molecular. Sabe-se que estes polissacarídeos possuem atividade biológica relevante em diversas aplicações, desde cosméticos, medicamentos e alimentação. Com este trabalho pretende-se otimizar os parâmetros de cultura e produção da microalga marinha Porphyridium cruentum, nomeadamente o EPS por ela produzido. Para isso, a microalga foi cultivada em meio de cultura NTIP e estudou-se a suplementação do mesmo com sulfato de magnésio (NTIP-MgSO4) e cloreto de magnésio (NTIP-MgCl2). Com este teste verificou-se uma extensão da fase exponencial no meio NTIP-MgSO4 quando comparado com o controlo (NTIP) e NTIP-MgCl2. Pretende-se também verificar a ação do EPS em relação a potenciais patogénicos humanos. Para isso, realizaram-se vários perfis de atividades biológicas, nomeadamente a capacidade antibacteriana, antifúngica e antibiofilme bacterianos. O EPS revelou capacidade antimicrobiana dependente da concentração. A 4% de EPS, o MRSA foi o que apresentou maior percentagem de inibição (~11%), seguido de S. enteritidis (~9%), E. coli (~7%) e C. albicans (~6%). P. aeruginosa foi o único microrganismo que não apresentou qualquer inibição em nenhuma das concentrações testadas. O EPS foi também testado para M. canis e T. rubrum, observando-se ausência de atividade antifúngica para o método testado. Estudou-se também o perfil prebiótico do EPS para 9 bactérias probióticas. Quando colocadas em meio MRS com glucose adicionando EPS, as bactérias L. plantarum, L. acidophilus La-5 (aerobiose) e L. acidophylus Ki, foram as que apresentaram maiores percentagens de estimulação, ~5%, ~19% e ~22% respetivamente. Relativamente ao estudo da capacidade antibiofilme bacteriano do EPS, testou-se para P. aeruginosa não se observando nenhuma atividade de antibiofilme por parte do EPS. Foi também estudada a fração da biomassa de P. cruentum onde se verificou a inibição de S. enteritidis e MSSA em extratos de clorofórmio, hexano e etanol. Este último extrato revelou ser o mais eficaz pois foi o que apresentou maiores valores de percentagens de inibição. Assim, Porphyridium cruentum demonstrou um efeito antimicrobiano seletivo, com potencial efeito prebiótico, assegurando assim um interesse elevado em aplicações alimentares, cosmética ou biomédicas.Porphyridium sp. is a microalgia, which is encapsulated inside a gel of sulfated exopolysaccharides (EPS). EPS’s have behaviors of dynamic fluid with production of highly viscous solutions and high molecular weight. It is known that these polysaccharides have relevant biological activity in various applications, from cosmetics and medicines to food. With this work, it was intended to optimize parameters of culture and production of the marine microalga Porphyridium cruentum, namely for its EPS. For this purpose, the microalga was cultivated NTIP medium and then studied with the supplementation of magnesium sulfate (NTIP-MgSO4) and magnesium chloride (NTIP-MgCl2). With this an extension of the exponential phase with the type NTIP-MgSO4 when compared to control (NTIP) and NTIP-MgCl2 was observed. The aim was also to verify the action of EPS concerning potential human pathogens. For that, several profiles of biological activity were carried out, namely antibacterial capacity, antifungal and bacterial antibiofilm. The EPS revealed antimicrobial activity dependente on concentration. At 4% EPS, MRSA showed the highest percentage of inhibition (~11%), followed by S. enteritidis (~ 9%), E. coli (~ 7%) and C. albicans (~ 6%). P. aeruginosa was the only microorganism that showed no inhibition in any of the concentrations tested. The EPS was also tested for M. canis and T. rubrum, but the results did not show antifungal activity for the tested method. The prebiotic profile EPS for 9 lactic bacteria has been studied. When cultured in the MRS médium with glucose and EPS, L. plantarum, L. acidophilus La-5 (aerobiose) and L. acidophylus Ki, have shown the highest stimulation, ~5%, ~19% and ~22%, respectively. Regarding the study of the capacity of bacterial antibiofilm of EPS, it was tested for P. aeruginosa, The results obtained did not show any antibiofilm activity of the EPS. The fraction of biomass of P. cruentum wasalso studyand it was analysed for its antibacterian performance in extracts of chloroform, hexane and ethanol. The inhibition of S. enteritidis and MSSA was observed, obtaining a bigger percentage of inhibition with ethanol extract. Thus, Porphyyridium cruentum demonstrated a selective antimicrobial effect, with potential prebiotic effect, thus assuring a high interest in applications, cosmetic or biomedical

Comparison of the accumulation of astaxanthin in Haematococcus pluvialis and other green microalgae under N-starvation and high light conditions

Haematococcus pluvialis gave the highest astaxanthin accumulation rate (2.7 mg l−1 day−1) and total astaxanthin content ( 22.7 mg g−1 biomass). Astaxanthin accumulation in Neochloris wimmeri, Protosiphon botryoides, Scotiellopsis oocystiformis, Chorella zofingiensis and Scenedesmus vacuolatus was, respectively, 19.2, 14.3, 10.9, 6.8 and 2.7 mg astaxanthin g−1 biomass, respectively.Xunta de Galicia; PGIDT00PXI10301PR

Dense non-rigid visual tracking with a robust similarity function

International audienceThis paper deals with dense non-rigid visual tracking robust towards global illumination perturbations of the observed scene. The similarity function is based on the sum of condi- tional variance (SCV). With respect to most approaches that minimize the sum of squared differences, which is poorly robust towards illumination variations in the scene, the choice of SCV as our registration function allows the approach to be naturally robust towards global perturbations. Moreover, a thin-plate spline warping function is considered in order to take into account deformations of the observed template. The proposed approach, after being detailed, is tested in nominal conditions and on scenes where light perturbations occur in order to assess the robustness of the approach

Airlift Column Photobioreactors for Porphyridium Sp. Culturing: Part I. Effects of Hydrodynamics and Reactor Geometry

Photosynthetic Microorganisms Have Been Attracting World Attention for their Great Potential as Renewable Energy Sources in Recent Years. Cost Effective Production in Large Scale, However, remains a Major Challenge to overcome. It is Known to the Field that Turbulence Could Help Improving the Performance of Photobioreactors Due to the So-Called Flashing Light Effects. Better Understanding of the Multiphase Fluid Dynamics and the Irradiance Distribution Inside the Reactor that Cause the Flashing Light Effects, as Well as Quantifying their Impacts on the Reactor Performance, Thus, Are Crucial for Successful Design and Scale-Up of Photobioreactors. in This Study, a Species of Red Marine Microalgae, Porphyridium Sp., Was Grown in Three Airlift Column Photobioreactors (I.e., Draft Tube Column, Bubble Column, and Split Column). the Physical Properties of the Culture Medium, the Local Fluid Dynamics and the Photobioreactor Performances Were Investigated and Are Reported in This Part of the Manuscript. Results Indicate that the Presence of Microalgae Considerably Affected the Local Multiphase Flow Dynamics in the Studied Draft Tube Column. Results Also Show that the Split Column Reactor Works Slightly Better Than the Draft Tube and the Bubble Columns Due to the Spiral Flow Pattern Inside the Reactor. © 2011 Wiley Periodicals, Inc