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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
Gellan gum is a long-chain extracellular polysaccharide, secreted by Sphingomonas elodea bacteria. Gellan biopolymer is an anionic linear heteropolysaccharide possessing repeating units of tetrasaccharide molecules such as α-l-rhamnose, β-d-glucose and β-d-glucuronic acid in the ratio of 1:2:1 with l-glycerate (Okiror and Jones 2012). In industry, gellan gum is manufactured by a fermentation process in an appropriate medium. Generally, gellan gum is synthesized in two acyl forms – high-acyl (HA) and low-acyl (LA) gellan gum. The gelation properties vary according to their acyl substitution form, as LA requires gel-promoting cations whereas HA produces gels by cooling down the hot gellan solutions (Sworn 2009a). Due to its gelling properties, gellan gums are widely used in the food and pharmaceutical industries (Krasaekoopt and Bhandari 2012, Morales and Ruiz 2016, Philp 2015).
Pharmaceutical Applications of Gellan Gum
Published in Amit Kumar Nayak, Md Saquib Hasnain, Dilipkumar Pal, Natural Polymers for Pharmaceutical Applications, 2019
Shakti Nagpal, Sunil Kumar Dubey, Vamshi Krishna Rapalli, Gautam Singhvi
Among various polysaccharide based natural polymer, gellan gum has been investigated for various pharmaceutical and biomedical application. Gellan gum is a bacterial polysaccharide which is obtained from Sphingomonas elodea. It was identified to possess a commercial advantage in 1978 during an extensive soil-water borne bacterial screening program by C.P. Kelco (USA). Produced from the strains of Sphigomonas, Gellan gum consists of rod-shaped, gram-negative, strict aerobe, chemoheterotrophic bacteria which produce yellowish pigmented colonies and consists of glycosphingolipids in their cell wall. Gellan is a linear polymer, anionic in nature and has a repeating sequence of tetra-saccharides consisting of two residues of β-D-Glucose (L-Rhamnose and β-D-Glucuronate) (Figure 4.1). The polysaccharide, which is biosynthesized has L-glyceryl substituents on O (2) and an acetyl group at O (6) of glucose unit in tetra-saccharide repeat sequences. During its commercial production, both the substituents get removed when treated with hot alkali and fermentation broth (Prajapati et al., 2013).
Introduction of biopolymer-based materials for ground hydraulic conductivity control
Published in Daniele Peila, Giulia Viggiani, Tarcisio Celestino, Tunnels and Underground Cities: Engineering and Innovation meet Archaeology, Architecture and Art, 2020
I. Chang, A.T.P. Tran, G.-C. Cho
Gellan gum is a linear polysaccharide produced by the bacterium Pseudomonas elodea, which has been investigated in the fields of pharmaceutical technology, biomedical applications (Osmałek et al., 2014), food industry (Morris et al., 2012, Saha and Bhattacharya, 2010, Imeson, 1992). Moreover, gellan gum applicability to geotechnical engineering such as soil strengthening (Chang and Cho, 2018, Chang et al., 2017, Chang et al., 2015b), hydraulic conductivity control (Chang et al., 2016a). In this study, low acyl gellan gum biopolymer supplied by Sigma Aldrich (CAS No.71010-52-1) has been used.
Cost-effective optimization of gellan gum production by Sphingomonas paucimobilis using corn steep liquor
Published in Preparative Biochemistry & Biotechnology, 2020
Jin Huang, Shengquan Zhu, Chuanbao Li, Chenglin Zhang, Yizhi Ji
Gellan gum, produced by Sphingomonas paucimobilis, is a widely used microbial exocellular polysaccharide with increasing commercial potential in the food and pharmaceutical industries. It is primarily used as stabilizing, emulsifying, texturing and gelling agents,[1–4] owing to its low dosage needs, high clarity, good flavor release, thermoreversible properties and resistance to acid and heat. In its native form, gellan gum is composed of tetrasaccharide repeating units (D-glucose, L-rhamnose, and D-glucuronic acid at the ratio of 2:1:1) and esterified substituents (one L-glycerate per repeating unit and one acetate every two sequences).[5] Moreover, deacylation of native gellan gum causes soft and elastic gels to become harder, and more brittle.
Enhanced cyanide biodegradation by immobilized crude extract of Rhodococcus UKMP-5M
Published in Environmental Technology, 2019
Maegala Nallapan Maniyam, Abdul Latif Ibrahim, Anthony E. G. Cass
Gellan gum and calcium alginate are widely capitalized for immobilization and encapsulation via the entrapment method due to its nontoxicity and biocompatibility. In addition, they can be easily obtained and these matrices are highly flexible allowing modification that provides protection and stability to the immobilized crude extract [20]. The utilization of alginate, in particular, provides simple gelation with divalent cations such as the calcium ion [21]. Gellan gum, on the other hand, presents itself as an attractive candidate for immobilization because of its heat resistance and pH resistance gelling properties [22]. For these reasons, both gellan gum and calcium alginate were used in the present study to obtain favourable process conditions.