Characterization of levan produced by a Paenibacillus sp. isolated from Brazilian crude oil

authors	Mendonca, CMN; Oliveira, RC; Freire, RKB; Piazentin, ACM; Pereira, WA; Gudina, EJ; Evtuguin, DV; Converti, A; Santos, JHPM; Nunes, C; Rodrigues, LR; Oliveira, RPS
nationality	International
journal	INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
author keywords	Levan; Physicochemical characterization; Thermomechanical stability
keywords	ANTIINFLAMMATORY ACTIVITY; FRUCTOOLIGOSACCHARIDES; EXOPOLYSACCHARIDE; POLYSACCHARIDES; POLYMERIZATION; WATER; OLIGOSACCHARIDES; OPTIMIZATION; BACTERIUM; FRUCTANS
abstract	A levan-type fructooligosaccharide was produced by a Paenibacillus strain isolated from Brazilian crude oil, the purity of which was 98.5% after precipitation with ethanol and dialysis. Characterization by FTIR, NMR spectroscopy, GC-FID and ESI-MS revealed that it is a mixture of linear beta(2 -+ 6) fructosyl polymers with average degree of polymerization (DP) of 18 and branching ratio of 20. Morphological structure and physicochemical properties were investigated to assess levan microstructure, degradation temperature and thermomechanical features. Thermal Gravimetric Analysis highlighted degradation temperature of 218 degrees C, Differential Scanning Calorimetry (DSC) glass transition at 81.47 degrees C, and Dynamic Mechanical Analysis three frequency-dependent transition peaks. These peaks, corresponding to a first thermomechanical transition event at 86.60 degrees C related to the DSC endothermic event, a second at 170.9 degrees C and a third at 185.2 degrees C, were attributed to different glass transition temperatures of oligo and polyfructans with different DP. Levan showed high morphological versatility and technological potential for the food, nutraceutical, and pharmaceutical industries.
publisher	ELSEVIER
issn	0141-8130
isbn	1879-0003
year published	2021
volume	186
beginning page	788
ending page	799
digital object identifier (doi)	10.1016/j.ijbiomac.2021.07.036
web of science category	12
subject category	Biochemistry & Molecular Biology; Chemistry, Applied; Polymer Science
unique article identifier	WOS:000688434300005