PRODUCTION OF EXTRACELLULAR POLYSACCHARIDES BY MUCOR RACEMOSUS

1958 ◽  
Vol 4 (3) ◽  
pp. 317-319 ◽  
Author(s):  
S. M. Martin
1994 ◽  
Vol 269 (6) ◽  
pp. 4299-4306 ◽  
Author(s):  
G.A. De Ruiter ◽  
A.W. Van Bruggen-Van der Lugt ◽  
P. Mischnick ◽  
P. Smid ◽  
J.H. Van Boom ◽  
...  

2020 ◽  
Author(s):  
Ian Sims ◽  
K Middleton ◽  
AG Lane ◽  
AJ Cairns ◽  
A Bacic

Microscopic examination of suspension-cultured cells of Phleum pratense L., Panicum miliaceum L., Phalaris aquatica L. and Oryza sativa L. showed that they were comprised of numerous root primordia. Polysaccharides secreted by these suspension cultures contained glycosyl linkages consistent with the presence of high proportions of root mucilage-like polysaccharides. In contrast, suspension-cultured cells of Hordeum vulgare L. contained mostly undifferentiated cells more typical of plant cells in suspension culture. The polysaccharides secreted by H. vulgare cultures contained mostly linkages consistent with the presence of glucuronoarabinoxylan. The soluble polymers secreted by cell-suspension cultures of Phleum pratense contained 70% carbohydrate, 14% protein and 6% inorganic material. The extracellular polysaccharides were separated into four fractions by anion-exchange chromatography using a gradient of imidazole-HCl at pH 7.0. From glycosyl-linkage analyses, five polysaccharides were identified: an arabinosylated xyloglucan (comprising 20% of the total polysaccharide), a glucomannan (6%), a type-II arabinogalactan (an arabinogalactan-protein; 7%), an acidic xylan (3%), and a root-slime-like polysaccharide, which contained features of type-II arabinogalactans and glucuronomannans (65%).


2020 ◽  
Author(s):  
Ian Sims ◽  
K Middleton ◽  
AG Lane ◽  
AJ Cairns ◽  
A Bacic

Microscopic examination of suspension-cultured cells of Phleum pratense L., Panicum miliaceum L., Phalaris aquatica L. and Oryza sativa L. showed that they were comprised of numerous root primordia. Polysaccharides secreted by these suspension cultures contained glycosyl linkages consistent with the presence of high proportions of root mucilage-like polysaccharides. In contrast, suspension-cultured cells of Hordeum vulgare L. contained mostly undifferentiated cells more typical of plant cells in suspension culture. The polysaccharides secreted by H. vulgare cultures contained mostly linkages consistent with the presence of glucuronoarabinoxylan. The soluble polymers secreted by cell-suspension cultures of Phleum pratense contained 70% carbohydrate, 14% protein and 6% inorganic material. The extracellular polysaccharides were separated into four fractions by anion-exchange chromatography using a gradient of imidazole-HCl at pH 7.0. From glycosyl-linkage analyses, five polysaccharides were identified: an arabinosylated xyloglucan (comprising 20% of the total polysaccharide), a glucomannan (6%), a type-II arabinogalactan (an arabinogalactan-protein; 7%), an acidic xylan (3%), and a root-slime-like polysaccharide, which contained features of type-II arabinogalactans and glucuronomannans (65%).


2020 ◽  
Author(s):  
Ian Sims ◽  
A Bacic

The soluble polymers secreted by cell-suspension cultures of Nicotiana plumbaginifolia contained 78% carbohydrate, 6% protein and 4% inorganic material. The extracellular polysaccharides were separated into three fractions by anion-exchange chromatography using a gradient of imidazole-HCl at pH 7 and the individual polysaccharides in each fraction were then isolated by selective precipitation and enzymic treatment. Monosaccharide and linkage compositions were determined for each polysaccharide after reduction of uronic acid residues and the degree of esterification of the various uronic acid residues in each polysaccharide was determined concurrently with the linkage types. Six components were identified: an arabinoxyloglucan (comprising 34% of the total polysaccharide) and a galactoglucomannan (15%) in the unbound neutral fraction, a type II arabinogalactan (an arabinogalactan-protein, 11%) and an acidic xylan (3%) in the first bound fraction, and an arabinoglucuronomannan (11%) and a galacturonan (26%) in the second bound fraction. © 1995.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 815
Author(s):  
Janja Trček ◽  
Iztok Dogsa ◽  
Tomaž Accetto ◽  
David Stopar

Bacteria produce a variety of multifunctional polysaccharides, including structural, intracellular, and extracellular polysaccharides. They are attractive for the industrial sector due to their natural origin, sustainability, biodegradability, low toxicity, stability, unique viscoelastic properties, stable cost, and supply. When incorporated into different matrices, they may control emulsification, stabilization, crystallization, water release, and encapsulation. Acetan is an important extracellular water-soluble polysaccharide produced mainly by bacterial species of the genera Komagataeibacter and Acetobacter. Since its original description in Komagataeibacter xylinus, acetan-like polysaccharides have also been described in other species of acetic acid bacteria. Our knowledge on chemical composition of different acetan-like polysaccharides, their viscoelasticity, and the genetic basis for their production has expanded during the last years. Here, we review data on acetan biosynthesis, its molecular structure, genetic organization, and mechanical properties. In addition, we have performed an extended bioinformatic analysis on acetan-like polysaccharide genetic clusters in the genomes of Komagataeibacter and Acetobacter species. The analysis revealed for the first time a second acetan-like polysaccharide genetic cluster, that is widespread in both genera. All species of the Komagataeibacter possess at least one acetan genetic cluster, while it is present in only one third of the Acetobacter species surveyed.


Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 298
Author(s):  
Despoina Konstantinou ◽  
Rafael V. Popin ◽  
David P. Fewer ◽  
Kaarina Sivonen ◽  
Spyros Gkelis

Sponges form symbiotic relationships with diverse and abundant microbial communities. Cyanobacteria are among the most important members of the microbial communities that are associated with sponges. Here, we performed a genus-wide comparative genomic analysis of the newly described marine benthic cyanobacterial genus Leptothoe (Synechococcales). We obtained draft genomes from Le. kymatousa TAU-MAC 1615 and Le. spongobia TAU-MAC 1115, isolated from marine sponges. We identified five additional Leptothoe genomes, host-associated or free-living, using a phylogenomic approach, and the comparison of all genomes showed that the sponge-associated strains display features of a symbiotic lifestyle. Le. kymatousa and Le. spongobia have undergone genome reduction; they harbored considerably fewer genes encoding for (i) cofactors, vitamins, prosthetic groups, pigments, proteins, and amino acid biosynthesis; (ii) DNA repair; (iii) antioxidant enzymes; and (iv) biosynthesis of capsular and extracellular polysaccharides. They have also lost several genes related to chemotaxis and motility. Eukaryotic-like proteins, such as ankyrin repeats, playing important roles in sponge-symbiont interactions, were identified in sponge-associated Leptothoe genomes. The sponge-associated Leptothoe stains harbored biosynthetic gene clusters encoding novel natural products despite genome reduction. Comparisons of the biosynthetic capacities of Leptothoe with chemically rich cyanobacteria revealed that Leptothoe is another promising marine cyanobacterium for the biosynthesis of novel natural products.


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