scholarly journals Characterization and Biotechnological Potential of Extracellular Polysaccharides Synthesized by Alteromonas Strains Isolated from French Polynesia Marine Environments

Marine Drugs ◽  
2021 ◽  
Vol 19 (9) ◽  
pp. 522
Author(s):  
Patrícia Concórdio-Reis ◽  
Vítor D. Alves ◽  
Xavier Moppert ◽  
Jean Guézennec ◽  
Filomena Freitas ◽  
...  

Marine environments comprise almost three quarters of Earth’s surface, representing the largest ecosystem of our planet. The vast ecological and metabolic diversity found in marine microorganisms suggest that these marine resources have a huge potential as sources of novel commercially appealing biomolecules, such as exopolysaccharides (EPS). Six Alteromonas strains from different marine environments in French Polynesia atolls were selected for EPS extraction. All the EPS were heteropolysaccharides composed of different monomers, including neutral monosaccharides (glucose, galactose, and mannose, rhamnose and fucose), and uronic acids (glucuronic acid and galacturonic acid), which accounted for up to 45.5 mol% of the EPS compositions. Non-carbohydrate substituents, such as acetyl (0.5–2.1 wt%), pyruvyl (0.2–4.9 wt%), succinyl (1–1.8 wt%), and sulfate (1.98–3.43 wt%); and few peptides (1.72–6.77 wt%) were also detected. Thermal analysis demonstrated that the EPS had a degradation temperature above 260 °C, and high char yields (32–53%). Studies on EPS functional properties revealed that they produce viscous aqueous solutions with a shear thinning behavior and could form strong gels in two distinct ways: by the addition of Fe2+, or in the presence of Mg2+, Cu2+, or Ca2+ under alkaline conditions. Thus, these EPS could be versatile materials for different applications.

1960 ◽  
Vol 38 (9) ◽  
pp. 1617-1624 ◽  
Author(s):  
M. J. Abercrombie ◽  
J. K. N. Jones ◽  
M. V. Lock ◽  
M. B. Perry ◽  
R. J. Stoodley

The extracellular polysaccharides produced by Cryptococcuslaurentii have been isolated and shown to consist of (A) an acidic polysaccharide containing D-mannose, D-xylose, and D-glucuronic acid; (B) a neutral polysaccharide containing D-glucose only.Preliminary structural studies on the acidic material suggest that it consists of a mannose-containing backbone with xylose and glucuronic acid as end groups, while the glucan contains 1 → 3, 1 → 4, 1 → 2, and (or) 1 → 6 linked residues.


1964 ◽  
Vol 42 (10) ◽  
pp. 1403-1413 ◽  
Author(s):  
G. A. Adams ◽  
S. M. Martin

Growth of Serratia marcescens on sucrose, D-glucose, D-galactose, and D-xylose as carbon sources did not affect the composition of the extracellular polysaccharides significantly. D-Glucose was the major component with lesser amounts of D-mannose, heptose, L-fucose, and L-rhamnose. Rhamnose did not appear until near the end of the active growth period and increased proportionately more than the other sugars thereafter. From the culture filtrate after 20 hours growth on sucrose, two acidic polysaccharides were isolated. They were markedly different in composition and electrophoretic behavior although both contained glucose as their major component. One was characterized by a relatively high content of rhamnose and heptose, the other by the presence of mannose; both contained glucuronic acid. Other impure polysaccharides were isolated from the culture filtrate. It seems likely that S. marcescens produced a spectrum of rather similar extracellular polysaccharides of which the two isolated ones comprise the main types.


1963 ◽  
Vol 41 (9) ◽  
pp. 2357-2361 ◽  
Author(s):  
P. A. J. Gorin ◽  
J. F. T. Spencer

The extracellular polysaccharide formed from Xanthomonas hyacinthi is shown to be a branched polymer containing glucuronic acid, mannose, and glucose. Acid and enzymic hydrolysis show the presence of β-D-Glp 1 → 4 D-Man and the 4-unit sequence β-D-GlpA1 → 2 D-Manp 1 → 3 β-D-Glp 1 → 4 D-Gl. Examination by the methylation technique showed the presence of a considerable proportion of 2-linked mannopyranose units. The spectrum of methyl glycosides formed from this polysaccharide and those from Xanthomonas maculofoliigardeniae and Xanthomonas translucens are similar, and in terms of sugar linkages differentiate them from that of Xanthomonas stewartii, which contains glucuronic acid, glucose, and galactose.


2021 ◽  
Author(s):  
Yosuke Nishimura ◽  
Susumu Yoshizawa

Marine microorganisms are immensely diverse and play fundamental roles in global geochemical cycling. Recent metagenome-assembled genome studies, with special attention to large-scale projects such as Tara Oceans, have expanded the genomic repertoire of marine microorganisms. However, published marine metagenome data has not been fully explored yet. Here, we collected 2,057 marine metagenomes (>29 Tera bps of sequences) covering various marine environments and developed a new genome reconstruction pipeline. We reconstructed 52,325 qualified genomes composed of 8,466 prokaryotic species-level clusters spanning 59 phyla, including genomes from deep-sea deeper than 1,000 m (n=3,337), low-oxygen zones of <90 μmol O2 per kg water (n=7,884), and polar regions (n=7,752). Novelty evaluation using a genome taxonomy database shows that 6,256 species (73.9%) are novel and include genomes of high taxonomic novelty such as new class candidates. These genomes collectively expanded the known phylogenetic diversity of marine prokaryotes by 34.2% and the species representatives cover 26.5 - 42.0% of prokaryote-enriched metagenomes. This genome resource, thoroughly leveraging accumulated metagenomic data, illuminates uncharacterized marine microbial dark matter lineages.


1967 ◽  
Vol 13 (1) ◽  
pp. 99-105 ◽  
Author(s):  
Noëlle Amarger ◽  
M. Obaton ◽  
H. Blachère

The composition of the extracellular polysaccharides of 10 strains of Rhizobium meliloti was investigated. Glucose, galactose, and glucuronic acid were found as components; their amounts, determined after hydrolysis as a percentage of the total sugars, varied from 82 to 86 for glucose, 13 to 16 for galactose, and 0.4 to 1.2 for glucuronic acid. No significant difference between the strains was found, which suggests a homogeneity of the extracellular polysaccharides of Rhizobium meliloti.


Molecules ◽  
2019 ◽  
Vol 24 (20) ◽  
pp. 3717
Author(s):  
Lionel Longe ◽  
Gil Garnier ◽  
Kei Saito

In this work, we proved the efficient synthesis of a bio-based hyper-branched polyphenol from a modified lignin degradation fragment. Protocatechuic acid was readily obtained from vanillin, a lignin degradation product, via alkaline conditions, and further polymerised to yield high molecular weight hyperbranched phenol terminated polyesters. Vanillic acid was also subjected to similar polymerisation conditions in order to compare polymerisation kinetics and differences between linear and hyperbranched polymers. Overall, protocatechuic acid was faster to polymerise and more thermostable with a degradation temperature well above linear vanillic acid polyester. Both polymers exhibited important radical scavenging activity (RSA) compared to commercial antioxidant and present tremendous potential for antioxidant applications.


2014 ◽  
Vol 1 ◽  
Author(s):  
Coelho Carina ◽  
Fernandes Joana ◽  
Silva Patrícia ◽  
Afonso Clélia ◽  
Sampaio Maria

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