Structural characterization and anticancer activity of extracellular polysaccharides from ascidian symbiotic bacterium Bacillus thuringiensis

• Published in: Carbohydrate polymers 2018-06, Vol.190, p.113-120
• Main Authors: Ramamoorthy, Sathishkumar, Gnanakan, Ananthan, S. Lakshmana, Senthil, Meivelu, Moovendhan, Jeganathan, Arun
• Format: Article
• Language: English
• Subjects: Animals; Anticancer activity; Antineoplastic Agents - chemistry; Antineoplastic Agents - pharmacology; Ascidians; Bacillus thuringiensis - cytology; Bacillus thuringiensis - physiology; Cell Line, Tumor; Cercopithecus aethiops; Extracellular polysaccharides; Extracellular Space - chemistry; Free Radical Scavengers - chemistry; Free Radical Scavengers - pharmacology; Humans; Monosaccharides - analysis; Polysaccharides, Bacterial - chemistry; Polysaccharides, Bacterial - pharmacology; Response surface methodology; Symbiosis; Urochordata - microbiology; Vero Cells
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2018.02.047

•EPS production was statistically optimized by RSM method.•This the first evidence of EPS production from ascidian symbiotic bacteria.•Fructose and Galactose were recorded as major sugars.•Structural features of EPS were studied through spectroscopy techniques.•EPS has showed promising antioxidant and anticancer effects. In the present study, extracellular polysaccharides (EPS) producing bacterium Bacillus thuringiensis RSK CAS4 was isolated from ascidian Didemnum granulatum and its production was optimized by response surface methodology. Fructose and galactose were found as the major monosaccharides in the EPS from the strain RSK CAS4. Functional groups and structural characteristics of the EPS were characterized with FT-IR and 1HNMR. The purified EPS showed potent antioxidant properties in investigation against DPPH, hydroxyl, superoxide free radicals. In vitro anticancer activity of purified EPS was evaluated on HEp-2 cells, A549 and Vero cell lines. Growth of cancer cells was inhibited by the EPS in a dose-dependent manner and maximum anticancer activity was found to be 76% against liver cancer at 1000 μg/ml. The antioxidant and anticancer potentials of theEPS from marine bacterium Bacillusthuringiensis RSK CAS4 suggests it as a potential natural source and its scopeas an alternative to synthetics for pharmaceutical application.