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Applications of Green Polymeric Nanocomposites
Published in Satya Eswari Jujjavarapu, Krishna Mohan Poluri, Green Polymeric Nanocomposites, 2020
Mukesh Kumar Meher, Krishna Mohan Poluri
Levan is a highly branched, high molecular weight, extracellularly produced non-structural microbial polysaccharide comprising of β(2→6)-linked fructans which are packed into a nano-sized spherical form, attaining greater stability than the linear polymer (Kasapis et al. 1994, Han 1989). Levan is biosynthesized by a variety of both gram-positive and gram-negative bacteria from fermentation of sucrose substrates through the activation of the levensucrase enzyme. Generally, levan is produced extracellularly by a wide range of bacteria: Acetobacter xylinum, Bacillus subtilis, Bacillus lentus, Bacillus licheniformis, Halomonas smyrnensis, Halomonas smyrnensis, Paenibacillus polymyxa, etc (Öner et al. 2016). In a study, levan polysaccharides were found to be effective hypoglycemic and antioxidant agents in diabetic conditions (Dahech et al. 2011). Due to its efficient biodegradability and biocompatibility properties, levan is used in personal care and medical applications (Öner et al. 2016).
Bioprocessing of Agrofood Industrial Wastes for the Production of Bacterial Exopolysaccharide
Published in V. Sivasubramanian, Bioprocess Engineering for a Green Environment, 2018
J. Kanimozhi, V. Sivasubramanian, Anant Achary, M. Vasanthi, Steffy P. Vinson, R. Sivashankar
Levan is a highly branched and complex homopolysaccharide of fructose. It is generally composed of d-fructofuranosyl residues attached together by β (2–6) and β (2–1) linkages. Levans are biosynthesized by the action of the enzyme levansucrase. Levan is synthesized from sucrose via the catalytic action of levansucrase, the enzyme responsible for both sucrose hydrolysis and the transfer of d-fructosyl residues from fructose to the levan chain by transfructosylation. Levans are primarily produced by the genera Bacillus, Rahnella, Aerobacter, Erwinia, Streptococcus, Pseudomonas, and Zymomonas (Bahl et al. 2010). Owing to the ease of production, levans have more advantages, as they are economically and industrially feasible with numerous applications. Apart from its biodegradability and biocompatibility properties, it has excellent biomedical properties; it is an anticarcinogenic, a hyperglycemic inhibitor, an anti-AIDS agent, an antioxidant, and an anti-inflammatory (Dahech et al. 2011). Due to its tremendous medicinal and polymeric properties, microbial levan is considered to be a valuable biopolymer with high potential.
Glycan-Based Nanocarriers in Drug Delivery
Published in Raj K. Keservani, Anil K. Sharma, Rajesh K. Kesharwani, Drug Delivery Approaches and Nanosystems, 2017
Songul Yasar Yildiz, Merve Erginer, Tuba Demirci, Juergen Hemberger, Ebru Toksoy Oner
Levan is a homopolysaccharide composed of β-D-fructofuranose with β-(2–6) linkages between fructose rings. Levan is produced by the action of levansucrase enzyme by many bacteria, fungi and actinomycetes through conversion of sucrose (Han and Clarke, 1990). This naturally occurring polymer is strongly adhesive, biocompatible and soluble in oil and water which makes this polymer preferable in foods, feeds, cosmetics, pharmaceutical and chemical industry (Kang et al., 2009). Levan-based DDS has been reported to form nanoparticles by self-assembly (Renuart and Viney, 2000). Nanostructured adhesive thin films for biomedical applications of levan were produced by matrix-assisted pulsed laser evaporation (Sima et al., 2011, 2012). The incorporation of phosphorylated-levan leads to thin films with higher adherent capacity for cells. Microbial levan microparticles were used as encapsulating agent for vitamin E and magnetic levan microparticles were used for trypsin immobilization (Maciel et al., 2012; Nakapong et al., 2013). Sarilmiser and Toksoy Oner (2014) investigated anticancer activity of oxidized levan against different human cancer cell lines and found that increasing oxidation degree and dose increases anticancer activity. Ternary blend films of levan with polyethylene oxide (PEO) and chitosan were investigated for biological, morphological and structural features (Bostan et al., 2014). For biomedical and tissue engineering this films could be used as wound healing bandages or surgical sealants (Costa et al., 2013). In the study of Sezer et al. (2011) various biodegradable levan-based nanoparticle systems with different particular size, charge, and release profiles were investigated and it was shown that levan nanoparticles can be used effectively as drug carriers for peptide and proteins. In a recent study, it was found that cancer cells have good affinity to functionalized low molecular weight (LMW) levan encapsulated solid lipid nanoparticles (Kim et al., 2015).
The antibiofilm potential of a heteropolysaccharide produced and characterized from the isolated marine bacterium Glutamicibacter nicotianae BPM30
Published in Preparative Biochemistry & Biotechnology, 2023
C. Trilokesh, B. S. Harish, Kiran Babu Uppuluri
Glucose, fructose, galactose, rhamnose, and arabinose were observed in other bacterial EPS reported in the literature. EPS from A. globiformis was composed of dextrose, fructose, galactose, and rhamnose.[53] EPS from A. viscosus contains mannuronic acid, glucose, and galactose.[45] The EPS obtained from Oceanobacillus iheyensis contained mannose, glucose, and arabinose.[51] Levan from Acetobacter xylinum NCIM 2526 had Fructose and fructo-oligosaccharides as its main components.[21] Glucose, galactose, rhamnose, and arabinose with traces of fucose, ribose, and mannose constituted for the EPS from Pseudoalteromonas haloplanktis CAM 025.[54]