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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).
Artificial neural network modeling and statistical optimization of medium components to enhance production of exopolysaccharide by Bacillus sp. EPS003
Published in Preparative Biochemistry & Biotechnology, 2023
Sivasankari Marimuthu, Sharon Mano Pappu J, Karthikeyan Rajendran
In this current study, the effect of different carbon sources on EPS yield was evaluated and depicted in Figure 1a. Among all the tested carbon sources, the experimental results suggest that sucrose is the most favorable carbon source for enhanced EPS production in consonance with the previous reports.[30,36,37] High level of expression of levansucrase enzyme is observed in the presence of the inducer, sucrose. This enzyme is responsible for the transfer of fructose units obtained from hydrolysis of sucrose to EPS.[15]