| Autor: |
Gudiña EJ; CEB-Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.; LABBELS-Associate Laboratory, Braga/Guimarães, Portugal., Couto MR; CEB-Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.; LABBELS-Associate Laboratory, Braga/Guimarães, Portugal., Silva SP; LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal., Coelho E; LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal., Coimbra MA; LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal., Teixeira JA; CEB-Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.; LABBELS-Associate Laboratory, Braga/Guimarães, Portugal., Rodrigues LR; CEB-Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.; LABBELS-Associate Laboratory, Braga/Guimarães, Portugal. |
| Abstrakt: |
Microbial exopolysaccharides (EPS) are promising alternatives to synthetic polymers in a variety of applications. Their high production costs, however, limit their use despite their outstanding properties. The use of low-cost substrates such as agro-industrial wastes in their production, can help to boost their market competitiveness. In this work, an alternative low-cost culture medium (CSLM) was developed for EPS production by Rhizobium viscosum CECT908, containing sugarcane molasses (60 g/L) and corn steep liquor (10 mL/L) as sole ingredients. This medium allowed the production of 6.1 ± 0.2 g EPS/L, twice the amount produced in the standard medium (Syn), whose main ingredients were glucose and yeast extract. This is the first report of EPS production by R. viscosum using agro-industrial residues as sole substrates. EPS CSLM and EPS Syn exhibited a similar carbohydrate composition, mainly 4-linked galactose, glucose and mannuronic acid. Although both EPS showed a good fit to the Herschel-Bulkley model, EPS CSLM displayed a higher yield stress and flow consistency index when compared with EPS Syn , due to its higher apparent viscosity. EPS CSLM demonstrated its potential use in Microbial Enhanced Oil Recovery by enabling the recovery of nearly 50% of the trapped oil in sand-pack column experiments using a heavy crude oil. |
