Physico-chemical characterization and aging effects of fructan exopolysaccharide produced by Weissella cibaria MD2 on Caenorhabditis elegans

In the present work, a probiotic bacteria Weissella cibaria MD2 was used for the production of exopolysaccharide (EPS), which was characterized and evaluated for several technological and biological activities. The RSM assisted optimization resulted in maximum production of EPS (12.58 g/L) when the MRS broth was supplemented with optimal carbon and nitrogen source. The EPS produced was purified using chromatography techniques and the monosaccharide analysis by HPLC showed that it was a fructan EPS. The NMR analysis suggested that the EPS MD2 is an inulin-type linear polysaccharide that consists of beta (1 -> 2) linkage. The scanning electron microscopy (SEM) images revealed that EPS MD2 has a thin sheet-like appearance with fewer fibers-like structures. The results from the thermal analysis showed that the EPS MD2 was highly thermostable and possess a degradation temperature of 279.90 degrees C. The x-ray diffraction pattern showed that the powdered EPS MD2 has a semi-crystalline nature. The EPS MD2 showed excellent antioxidant activities to scavenge free radicals. The fructan EPS showed a promising effect in increasing oxidative stress tolerance and enhancing the lifespan of C. elegans by activating the nuclear localization of DAF-16. The incredible physico-chemical and antioxidant properties (in vitro and in vivo) of this EPS can be implemented in the pharmaceutical and food industry.

Automated summary

The probiotic bacteria Weissella cibaria MD2 was used to produce exopolysaccharide (EPS) with excellent antioxidant activities, which can increase oxidative stress tolerance and enhance the lifespan of C. elegans.