|LONDON, L - Teagasc (AGRICULTURE AND FOOD DEVELOPMENT AUTHORITY)|
|WANG, L - Teagasc (AGRICULTURE AND FOOD DEVELOPMENT AUTHORITY)|
|FITZGERALD, G - University College Cork|
|STANTON, C - Teagasc (AGRICULTURE AND FOOD DEVELOPMENT AUTHORITY)|
|ROSS, R - Teagasc (AGRICULTURE AND FOOD DEVELOPMENT AUTHORITY)|
Submitted to: Journal of Applied Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2014
Publication Date: 5/1/2014
Publication URL: http://handle.nal.usda.gov/10113/5642481
Citation: London, L.E., Price, N.P., Wang, L., Fitzgerald, G.F., Stanton, C., Ross, R.P. 2014. Characterization of a bovine isolate Lactobacillus mucosae DPC 6426 which produces an exopolysaccharide composed predominantly of mannose residues. Journal of Applied Microbiology. 117:509-517.
Interpretive Summary: Lactobacillus mucosae is a bacterium originally isolated from the gut of piglets and that may be important to the general health of these animals. Some Lactobacillus strains produce a secreted polysaccharide (called exopolysaccharide, or EPS) when grown in culture. We have investigated the EPS produced by a particular Lactobacillus strain using a variety of techniques. Our conclusion, based on the results of these investigations, indicate that the robustness of the EPS-producing strain may make it more useful in food applications, and/or as a probiotic culture.
Technical Abstract: Aim: Identification of exopolysaccharide (EPS)-producing lactobacilli as EPS production is potentially a very important trait among probiotic lactobacilli from technological and health promoting perspectives. Methods and Results: Characterization of EPS-producing Lactobacillus mucosae DPC 6426 in detail based on 16S rRNA sequencing, sugar fermentation analysis, phenotypic microarray technology and EPS production using scanning electron and atomic force microscopy. The EPS was found to consist of mannosyl residues, with mannose, glucose and galactose found to be the major sugar residues present in an approximate ratio of 3: 2: 2. The strain was compared to non-EPS-producing Lb. mucosae DPC 6420 following exposure to salt, bile, acid and heat stresses. Lb. mucosae DPC 6426 exhibited 2-fold increased (p< 0.05) survival during 120 min exposure to 5M NaCl, 3-fold increased survival during 90 min exposure to 0.7% (w/v) bile (p< 0.05), 3-fold increased survival when exposed to simulated gastric juice (p< 0.001) for 10 min and 5-fold increased survival during 60 min exposure to HCl (p< 0.01) compared with Lb. mucosae DPC 6420. Furthermore, Lb. mucosae DPC 6426 was found to be more heat tolerant (p< 0.001) compared with Lb. mucosae DPC 6420 during 30 min exposure to 55°C. Conclusion: These data indicate that the EPS-producing Lb. mucosae DPC 6426 exhibits technological and biological robustness compared to a non-EPS-producing Lb. mucosae strain. Impact of Study: The data implicates the potential suitability of EPS-producing Lb. mucosae DPC 6426 in food applications, and/or as a probiotic culture.