title: Osmoprotectants and cryoprotectants for Listeria monocytogenes.
abstract: Listeria monocytogenes is a foodborne pathogen that can grow in high osmotic strength environments and at refrigeration temperatures. Glycine betaine, proline betaine, acetylcarnitine, carnitine, gamma-butyrobetaine and 3-dimethylsulphoniopropionate all acted as osmoprotectants, as evidenced by an increase in growth rate of L. monocytogenes 10403S and Scott A when provided with these compounds, while being stressed in defined medium containing 0.7 M NaCl. These same compounds exhibited cryoprotective activity, as evidenced by increasing the growth rate of L. monocytogenes at 5 degrees C. Ectoine, hydroxy ectoine, pipecolic acid and proline were ineffective as osmoprotectants or cryoprotectants under these conditions. The presence of osmoprotectants and cryoprotectants in foods may provide compounds assisting L. monocytogenes to overcome the barriers of high osmotic strength and low temperature that otherwise control microbial growth.
authors.affiliation: Microbial Food Safety Research Unit, Eastern Regional Research Center, Agricultural Research Service, US Department of Agriculture, Wyndmoor, PA, USA.
authors.forename: D O
authors.initials: DO
authors.lastname: Bayles
authors.forename: B J
authors.initials: BJ
authors.lastname: Wilkinson
mesh_terms: D000108:Acetylcarnitine / Q000494:pharmacology; D001622:Betaine / Q000031:analogs & derivatives / Q000494:pharmacology; D002331:Carnitine; D003080:Cold Temperature; D003451:Cryoprotective Agents / Q000494:pharmacology*; D003470:Culture Media; D005516:Food Microbiology; D006801:Humans; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000254:growth & development; D009994:Osmolar Concentration; D011392:Proline / Q000031:analogs & derivatives / Q000494:pharmacology; D012965:Sodium Chloride; D013452:Sulfonium Compounds / Q000494:pharmacology
chemical_list: D003451:Cryoprotective Agents; D003470:Culture Media; D013452:Sulfonium Compounds; D001622:Betaine; C002889:gamma-butyrobetaine; D012965:Sodium Chloride; D000108:Acetylcarnitine; D011392:Proline; C068078:dimethylpropiothetin; C003342:stachydrine; D002331:Carnitine