Characterization of the properties of Pediococcus parvulus for probiotic or protective culture use.
Pediococcus parvulus 2.6 (previously Pediococcus damnosus 2.6, here confirmed as P. parvulus by 16S DNA sequencing) displayed antibacterial activity toward several bacterial species, including isolates found as contaminants in oats, herein genetically identified as Bacillus cereus. No inhibition of Listeria monocytogenes was found under the conditions used. Antibacterial activity was retrieved after ammonium sulfate or acetone precipitation showed it to be peptide mediated. P. parvulus 2.6 has previously shown good technological properties in oat-based products. This, together with the currently found inhibition of food spoilage microorganisms like B. cereus, makes it suitable as a food protective culture. Survival trials of P. parvulus 2.6 at conditions mimicking the gastrointestinal tract were prompted by previously found cholesterol-lowering effects in humans after consumption of oat products cofermented by using P. parvulus 2.6 and Bifidobacterium spp. Viability was measured with in vitro, gutlike simulations at 37 degrees C. High survival was shown under two of three conditions (gastric juice, bile, and small intestine juice), defined as main obstacles of the gastrointestinal tract. The critical step was bile exposure. At a concentration of 20%, viability was low, but 0.3% bile (mean concentration in the intestine) did not have a major influence on growth. Viability of P. parvulus 2.6 was significantly decreased in gastric juice at pH 1.5 (with pepsin), but it was not significantly affected at pH 2.5, and was also improved at a lower pH in 20% oat milk. Viability was judged sufficient for colonization at gutlike conditions, qualifying the strain for further probiotic studies.
Immerstrand
Tina
T
Department of Biotechnology, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, 22100 Lund, Sweden.
Paul
Catherine J
CJ
Rosenquist
Anna
A
Deraz
Sahar
S
Mårtensson
Olof Böök
OB
Ljungh
Asa
A
Blücher
Anna
A
Oste
Rickard
R
Holst
Olle
O
Karlsson
Eva Nordberg
EN
D000898:Antibiosis; D018554:Avena / Q000382:microbiology*; D041981:Gastrointestinal Tract / Q000382:microbiology* / Q000502:physiology*; D005772:Gastrointestinal Transit; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008089:Listeria monocytogenes / Q000254:growth & development; D050296:Microbial Viability; D010376:Pediococcus / Q000502:physiology*; D019936:Probiotics / Q000008:administration & dosage / Q000493:pharmacokinetics