Production and structural characterisation of dextran from an indigenous strain of <i>Leuconostoc mesenteroides </i><scp>BA</scp>08 in Whey

Abstract

In this work, the production of dextran was carried out in whey‐supplemented media using Leuconostoc mesenteroides BA 08. Different growth and nutritional parameters were optimised to maximise the dextran production. Batch production in whey‐based media under optimised nutritional and growth conditions yielded a dextran concentration of 17.25 g/L. Structural analysis of the purified polymer by FT ‐ IR , 1D 1 H and 13 C nuclear magnetic resonance methodology revealed that polymer was a linear dextran having 93% α‐(1→6) linkage in the main chain. The morphology of the dried dextran and dextran‐producing cells was also studied by scanning electron microscope which showed a granular and porous or weblike structure, respectively. The results obtained showed that the industrial whey supplemented with nutrients such as sucrose, yeast extract and K 2 HPO 4 can serve as an ideal growth medium for dextran production. The optimised fermentation and nutritional parameters can be further scaled up to establish the potential for the commercial production of food‐grade dextran from whey as part of a novel cost‐effective and environment‐friendly approach.