Exopolysaccharide production by Propionibacterium acidi-propionici on milk microfiltrate

• Published in: Journal of applied microbiology Vol. 90; no. 5; pp. 779 - 787
• Main Authors: Gorret, N, Maubois, J.L, Ghoul, M, Engasser, J.M
• Format: Journal Article
• Language: English
• Published: Oxford UK Blackwell Science Ltd 01-05-2001; Blackwell Science; Oxford University Press; Wiley
• Subjects: Anaerobiosis; Animals; bacteria; Biological and medical sciences; biomass; Biotechnology; Culture Media; exopolysaccharides; Fermentation; Fundamental and applied biological sciences. Psychology; Kinetics; lactose; Life Sciences; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; Microbiology and Parasitology; milk; Milk - metabolism; organic acids and salts; Polysaccharides - chemistry; Polysaccharides - metabolism; Propionibacterium - growth & development; Propionibacterium - metabolism; Propionibacterium acidipropionici; Reproducibility of Results; Rheology; viscosity; yeast extract; Yeasts; Microorganism growth; Production; Propionibacteriaceae; Microorganism culture; Filtrate; Bacteria; Propionibacterium acidipropionici; Actinomycetes; Extracellular; Polysaccharide; Milk; Rheological properties; POLYSACCHARIDE
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1046/j.1365-2672.2001.01306.x

Aims: The aims of this work were to evaluate growth and exopolysaccharide (EPS) production properties of Propionibacterium acidi-propionici DSM 4900 on milk permeate. Methods and Results: Anaerobic growth on milk permeate was only possible if supplemented with yeast extract (YE). Fermentation capacities of the strain were significantly improved by further increasing the supplemented YE. At 5 g l(-1) YE, consumption of 45 g l(-1) lactose to produce 9 g l(-1) biomass, 34 g l(-1) organic acids and 0.65 g l(-1) EPS was observed. From a kinetic point of view, EPS production occurred during the bacteria growth phase. At the excreted polysaccharide level, the medium showed shear-thinning behaviour with a relatively high apparent viscosity of up to 30 mPa.s (milli.Pascal.second) at a shear rate of 17 s(-1). Conclusions: EPS production by P. acidi-propionici DSM 4900 on milk permeate showed promising rheological behaviour of the milk-derived medium obtained, even at a low production level. Significance and Impact of the Study: A kinetic study on EPS production by a food-grade bacterium that could be used in situ in alimentation was carried out.