A strain with high exopolysaccharide (EPS) production was isolated from soil and identified as Bacillus mojavensis based on the 16S rRNA gene sequencing and biochemical properties. The EPS produced simultaneously with the growth phase reached a maximum of 22 g/L after attaining a stationary phase with sucrose used as sole carbon source. B. mojavensis EPS (BM-EPS) was recovered, fractionated by ethanol precipitation and analysed by NMR and methylation analyses. The BM-EPS was found to be composed of (β2→6)-Fruf residues, characteristic of a levan, with an average molecular weight of 2.3 MDa. A homogeneous micro-porous and rough structure matrix was observed by SEM of the freeze-dried powdered sample. A concentration-dependent water-soluble nature was observed, with good water (5.3 g/g) and oil (36 g/g) holding capacities. The levan displayed good emulsification activity with excellent stability against food grade oil, thus favoring it as a promising emulsifying agent to food industries.
methylation analysis, exopolysaccharide, levan, Bacillus mojavensis, interfacial properties
NCBI PubMed ID: 33139122Publication DOI: 10.1016/j.foodchem.2020.128456Journal NLM ID: 7702639Publisher: Elsevier Applied Science Publishers
Correspondence: Anissa Haddar
Institutions: LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, Aveiro, Portugal, Laboratory of Plants Improvement and Valorization of Agroressources, National School of Engineering of Sfax (ENIS), University of Sfax, Sfax 3038, Tunisia, Common Service Unit of Bioreactor Coupled with an Ultrafilter, National School of Engineering of Sfax (ENIS), University of Sfax, Sfax 3038, Tunisia
Methods: 13C NMR, methylation, GC-MS, composition analysis, statistical analysis, reduction with NaBH4, HPLC-SEC, SEM, emulsifying activity determination, WHC, OHC, taxonomy studies
Found