Isolation and identification of the alga-symbiotic bacterium Gordonia and characterisation of its exopolysaccharide

• Published in: Natural product research Vol. 38; no. 3; pp. 523 - 529
• Main Authors: Liu, Wang, Xing, Xiangying, Dong, Qinglin, Liu, Xiaohang, Li, Wenna
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis Ltd 2024
• Subjects: Actinobacteria; Algae; Aquatic plants; Bacteria; Exopolysaccharides; Galactose; Glucose; Gordonia; Industrial applications; Mannose; Molecular Weight; Physiochemistry; Polysaccharides; Pseudoplasticity; RNA, Ribosomal, 16S - genetics; rRNA 16S; Sodium chloride; Thermal stability; exopolysaccharide; Gordonia terrae; alga-symbiotic; emulsifying activity; NMR spectrum
• ISSN: 1478-6419; 1478-6427
• DOI: 10.1080/14786419.2022.2123477

An exopolysaccharide (EPS)-producing bacterium TD18, isolated from the culture broth of green alga , was identified as based on the 100% identity of 16S rRNA sequences and designated TD18. The results of compositional and structural analyses and physiochemical tests show that (1) the exopolysaccharide produced by TD18 (TD18-EPS) is an acidic hetero-polysaccharide with a molecular weight of 23 kDa, consisting of glucose, mannose, galactose and glucuronic acid, and (2) TD18-EPS is of high thermal stability with a degradation temperature of 308 °C, the solution of which is non-Newtonian pseudoplastic fluid exhibiting good emulsifying properties over a wide range of temperatures, pH and NaCl concentrations. Hence, TD18 is the first alga-symbiotic strain identified thus far, while TD18-EPS is unique in terms of composition and structure, different from the known EPS, with excellent physiochemical properties and thus has potential applications in industry.