title: Evaluation of culture media for selective enumeration of bifidobacteria and lactic acid bacteria.
abstract: The purpose of this study was to test the suitability of Transgalactosylated oligosaccharides-mupirocin lithium salt (TOS-MUP) and MRS-clindamycin-ciprofloxacin (MRS-CC) agars, along with several other culture media, for selectively enumerating bifidobacteria and lactic acid bacteria (LAB) species commonly used to make fermented milks. Pure culture suspensions of a total of 13 dairy bacteria strains, belonging to eight species and five genera, were tested for growth capability under various incubation conditions. TOS-MUP agar was successfully used for the selective enumeration of both Bifidobacterium animalis subsp. lactis BB-12 and B. breve M-16 V. MRS-CC agar showed relatively good selectivity for Lactobacillus acidophilus, however, it also promoted the growth of Lb. casei strains. For this reason, MRS-CC agar can only be used as a selective medium for the enumeration of Lb. acidophilus if Lb. casei is not present in a product at levels similar to or exceeding those of Lb. acidophilus. Unlike bifidobacteria and coccus-shaped LAB, all the lactobacilli strains involved in this work were found to grow well in MRS pH 5.4 agar incubated under anaerobiosis at 37 °C for 72 h. Therefore, this method proved to be particularly suitable for the selective enumeration of Lactobacillus spp.
authors.affiliation: Institute of Food Science Faculty of Agricultural and Food Sciences University of West Hungary Mosonmagyaróvár Hungary Institute of Food Science, Faculty of Agricultural and Food Sciences, University of West Hungary, Mosonmagyaróvár, Hungary.
authors.forename: Judit
authors.initials: J
authors.lastname: Süle
authors.affiliation: Hungarian Dairy Research Institute Mosonmagyaróvár Hungary Hungarian Dairy Research Institute, Mosonmagyaróvár, Hungary.
authors.forename: Tímea
authors.initials: T
authors.lastname: Kõrösi
authors.affiliation: Hungarian Dairy Research Institute Mosonmagyaróvár Hungary Hungarian Dairy Research Institute, Mosonmagyaróvár, Hungary.
authors.forename: Attila
authors.initials: A
authors.lastname: Hucker
authors.affiliation: Institute of Food Science Faculty of Agricultural and Food Sciences University of West Hungary Mosonmagyaróvár Hungary Institute of Food Science, Faculty of Agricultural and Food Sciences, University of West Hungary, Mosonmagyaróvár, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Varga
mesh_terms: D058491:Bacterial Load / Q000379:methods*; D001644:Bifidobacterium / Q000302:isolation & purification*; D003470:Culture Media / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007778:Lactobacillus / Q000302:isolation & purification*; D012641:Selection, Genetic; D013696:Temperature; D013997:Time Factors
chemical_list: D003470:Culture Media
keywords: Bifidobacterium; Lactobacillus acidophilus; ciprofloxacin; clindamycin; mupirocin