Exopolysaccharide from marine microalgae belonging to the genus: fragile gel behavior and suspension stability.

With the aim to find new polysaccharides of rheological interest with innovated properties, rhamnofucans produced as exopolysaccharides (EPS) in a photobioreactor (PBR) and an airlift bioreactor (ABR) by the marine microalgae Glossomastix sp. RCC3707 and RCC3688 were fully studied. Chemical characterizations have been conducted (UHPLC - MS HR).

Role of some structural features in EPS from microalgae stimulating collagen production by human dermal fibroblasts.

Exopolysaccharides (EPS) from the microalgae , , sp., sp., sp.

Exopolysaccharides from Microalgae and Cyanobacteria: Diversity of Strains, Production Strategies, and Applications.

Microalgae and cyanobacteria are photosynthetic organisms that can produce/accumulate biomolecules with industrial interest. Among these molecules, EPSs are macromolecular polysaccharidic compounds that present biological activities and physico-chemical properties, allowing to consider their valorization in diverse commercial markets, such as cosmetic, therapeutic, nutraceutic, or hydrocolloids areas. The number of microalgae and cyanobacteria strains described to produce such EPSs has increased in recent years as, among the 256 producing strains gathered in this review, 86 were published in the last 10 years (~33%).

Exploring the Diversity of Red Microalgae for Exopolysaccharide Production.

Microalgae constitute a remarkable biological diversity but a limited number of them have been the object of study for their ability to produce exoplysaccharides (EPS). Among them, the red marine microalgae or produce sulphated EPS, exhibiting some biological activities with potential interest in the pharmaceutical and cosmetic industries. EPS from and being relatively similar in their composition, it has long been considered that all the red microalgae produced similar EPS and no attention was paid to other red microalgae.

A New, Quick, and Simple Protocol to Evaluate Microalgae Polysaccharide Composition.

In this work, a new methodological approach, relying on the high specificity of enzymes in a complex mixture, was developed to estimate the composition of bioactive polysaccharides produced by microalgae, directly in algal cultures. The objective was to set up a protocol to target oligomers commonly known to be associated with exopolysaccharides' (EPS) nutraceutical and pharmaceutical activities (i.e.

Potential of Exopolysaccharide from to Contend with Bacterial Proliferation, Biofilm Formation, and Breast Cancer.

Exopolysaccharide (EPS) from marine microalgae are promising sources of a new generation of drugs. However, lot of them remain to be discovered and tested. In this study, EPS produced by and its oligomers prepared by High Pressure Homogenizer have been tested for different biological activities, i.

Polyethyleneimine as a tool for compounds fractionation by flocculation in a microalgae biorefinery context.

In the context of emerging biorefinery for microalgae, polyethyleneimine (PEI), has been tested in order to achieve separation of fat-soluble and water-soluble compounds from Haematococcus pluvialis. Several parameters were taken into account (ratio between sample and PEI, pH, and ionic strength) and 2 conditions (0.075% PEI pH 7.

Limnospira indica PCC8005 growth in photobioreactor: model and simulation of the ISS and ground experiments.

The Arthrospira-B experiment is the first experiment in space ever allowing the online measurements of both oxygen production rate and growth rate of Limnospira indica PCC8005 in batch photobioreactors running on-board ISS. Four bioreactors were integrated in the ISS Biolab facility. Each reactor was composed of two chambers (gas and liquid) separated by a PTFE membrane and was run in batch conditions.

Optimal cultivation towards enhanced biomass and floridean starch production by Porphyridium marinum.

Optimal conditions for maximal biomass and starch production by the marine red microalgae Porphyridium marinum were investigated. Box-Behnken Design was used to model the effect of light intensity, NaNO concentration and salinity on the growth of microalgae but also on their starch and protein contents. These three factors increased biomass production by 13.

New horizons in culture and valorization of red microalgae.

Research on marine microalgae has been abundantly published and patented these last years leading to the production and/or the characterization of some biomolecules such as pigments, proteins, enzymes, biofuels, polyunsaturated fatty acids, enzymes and hydrocolloids. This literature focusing on metabolic pathways, structural characterization of biomolecules, taxonomy, optimization of culture conditions, biorefinery and downstream process is often optimistic considering the valorization of these biocompounds. However, the accumulation of knowledge associated with the development of processes and technologies for biomass production and its treatment has sometimes led to success in the commercial arena.

Enhanced B-phycoerythrin production by the red microalga Porphyridium marinum: A powerful agent in industrial applications.

The production of B-phycoerythrin (B-PE) from the red microalga Porphyridium marinum was optimized before to purify it and subsequently study its antioxidant activities. NaNO KHPO and metal traces concentrations of the culture medium, and luminosity parameters were chosen, according to the Plackett-Burman design, as the most influent factors on the B-PE production by P. marinum.

Rheological and functional properties of asafoetida gum.

The asafoetida gum was extracted and purified from oleo-gum-resin of Ferula assa foetida root and characterized by high pressure anions exchange chromatography after acidic hydrolysis. It was composed of Gal:Ara:Rha:GlcA with the ratio 11.5:5.

Extraction and characterization of an alginate from the Iranian brown seaweed Nizimuddinia zanardini.

Sodium alginate from Nizimuddinia zanardini (an Iranian brown algae) was extracted with acid and alkaline solutions, partially and totally hydrolyzed and analyzed for its biochemical composition. H NMR spectroscopy, SEC-MALLS, HPAEC and FT-IR were performed to determine its structure and its physico-chemical properties. This alginate has a M/G ratio of 1.

Structural characterization and thermal behavior of a gum extracted from Ferula assa foetida L.

The gum asafoetida, an oleo-gum-resin from root of Ferula assa foetida, was extracted through alcoholic procedure followed by water extraction and then biochemically characterized using colorimetric assays, Fourier infrared spectroscopy, gas chromatography coupled to mass spectrometry, and 1D and 2D nuclear magnetic resonance. The gum was mainly composed of carbohydrates (67.39% w/w) with a monosaccharide distribution of 11.

Effects of nutritional conditions on growth and biochemical composition of Tetraselmis sp.

Background: This study aimed to maximize biomass concentration, biomass productivity and biochemical composition of the marine microalga Tetraselmis sp.

Methods: In the current study, Box-Behnken Design was used to model the effect of NaNO, NaHPO, metals and vitamins in the F/2 medium on the growth, total chlorophylls, carotenoids and starch contents. The total chlorophylls content was quantified by spectrophotometry.

Production, extraction and characterization of microalgal and cyanobacterial exopolysaccharides.

The current interest of scientific but also industrial communities for the exploitation of microalgae is correlated with the development of specific culture and downstream processes. These processes are currently in progress, and the increasing of knowledges led to emergence of high value compounds such as pigments, proteins, polysaccharides, unsaturated fatty acids, enzymes and others. Exopolysaccharides from microalgae have been at this time poorly explored despite their original structural features associated with specific biological and physico-chemical properties.

Improvement of exopolysaccharide production by Porphyridium marinum.

With the aim to optimize the production of exopolysaccharide (EPS) by Porphyridium marinum, cultures in photobioreactors were conducted on a modified Provasoli medium (P) and compared to a new medium (Pm) with an elemental composition of N0.0205S0.0597P0.

Haematococcus pluvialis soluble proteins: Extraction, characterization, concentration/fractionation and emulsifying properties.

A water-soluble matrix was extracted from green vegetative Haematococcus pluvialis through high-pressure cell disruption either at native pH (5.7) or with pH shifting to neutral (7). The resulting supernatant is mainly composed of carbohydrates and proteins, with the highest yield of proteins obtained at neutral pH (73±2% of total biomass proteins).

Structural Characterization and Biological Activities of Polysaccharides from Olive Mill Wastewater.

Olive mill wastewater (OMWW), the main waste product of olive oil extraction process, was investigated as a source of polysaccharides. The yield of alcohol insoluble residue (AIR) was 20.5 % based on the dry matter of OMWW.

Optimisation of culture parameters for exopolysaccharides production by the microalga Rhodella violacea.

A unicellular Rhodophyte was identified by sequencing of its 18S rRNA encoding gene as belonging to the Rhodella violacea specie. With the objective to optimise the production of biomass and exopolysaccharide by this strain, effects of irradiance, pH and temperature on its photosynthetic activity were investigated. In a second time a stoichiometric study of the well-known f/2 medium led to its supplementation in N and P to increase biomass and then exopolysaccharide yields when the strain was cultivated in photobioreactors.

Separation and fractionation of exopolysaccharides from Porphyridium cruentum.

In this work the extraction of EPSs from culture media of Porphyridium cruentum, by dialysis, solvent-precipitation with 3 polar alcohols (methanol, ethanol and isopropanol) and membrane separation techniques has been studied. Diafiltration (DF) using a membrane with a 300 kDa molecular weight cut off was the most efficient technique compared to solvent-extraction and dialysis methods. After extraction, EPS fraction was characterized in terms of rheological properties and biochemical content.

Rheological behavior and non-enzymatic degradation of a sulfated galactan from Halymenia durvillei (Halymeniales, Rhodophyta).

The rheological behavior of a sulfated galactan extracted from Halymenia durvillei, a red seaweed collected in the coastal waters of a small island of Madagascar (Nosy-be in Indian Ocean), was investigated in dilute and semi-dilute solutions. In dilute solution with NaCl at 0.3 M, the polysaccharide adopted a coil conformation whereas, at higher concentrations, the polymer had the behavior of shear-thinning fluid, typical of polymer with high molar mass or semi-rigid conformation.

Spectral kinetic modeling and long-term behavior assessment of Arthrospira platensis growth in photobioreactor under red (620 nm) light illumination.

The ability to cultivate the cyanobacterium Arhtrospira platensis in artificially lightened photobioreactors using high energetic efficiency (quasi-monochromatic) red LED was investigated. To reach the same maximal productivities as with the polychromatic lightening control conditions (red + blue, P/2e(-) = 1.275), the need to work with an optimal range of wavelength around 620 nm was first established on batch and continuous cultures.

New developments and prospective applications for beta (1,3) glucans.

Publications and patents relative to newly observed functions of beta-(1,3)-D-glucans have notably increased in the last few years with the exploitation of their biological activities. The term beta-(1,3)-D-glucans includes a very large number of polysaccharides from bacterial, fungal and vegetable sources. Their structures have a common backbone of beta-(1,3) linked glucopyranosyl residues but the polysaccharidic chain can be beta-(1,6) branched with glucose or integrate some beta-(1,4) linked glucopyranosyl residues in the main chain.

Phase transitions as a function of osmotic pressure in Saccharomyces cerevisiae whole cells, membrane extracts and phospholipid mixtures.

Fourier Transform Infrared spectroscopy (FTIR) was used to determine the phase transition temperature of whole Saccharomyces cerevisiae W303-1 A cells as a function of Aw in binary water-glycerol media. A phase transition occurred at 12 degrees C in water, at 16.5 degrees C at Aw=0.