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Sustainable Exopolysaccharide Production by Rhizobium viscosum CECT908 Using Corn Steep Liquor and Sugarcane Molasses as Sole Substrates

Authors :
Eduardo J. Gudiña
Márcia R. Couto
Soraia P. Silva
Elisabete Coelho
Manuel A. Coimbra
José A. Teixeira
Lígia R. Rodrigues
Source :
Polymers, Vol 15, Iss 1, p 20 (2022)
Publication Year :
2022
Publisher :
MDPI AG, 2022.

Abstract

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. EPSCSLM and EPSSyn 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, EPSCSLM displayed a higher yield stress and flow consistency index when compared with EPSSyn, due to its higher apparent viscosity. EPSCSLM 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.

Details

Language :
English
ISSN :
20734360
Volume :
15
Issue :
1
Database :
Directory of Open Access Journals
Journal :
Polymers
Publication Type :
Academic Journal
Accession number :
edsdoj.b8cce784265b47678b692dfaaec97d77
Document Type :
article
Full Text :
https://doi.org/10.3390/polym15010020