title: Development of a selective culture medium for bifidobacteria, Raffinose-Propionate Lithium Mupirocin (RP-MUP) and assessment of its usage with Petrifilm™ Aerobic Count plates.
abstract: This study aimed to develop a selective culture media to enumerate bifidobacteria in fermented milk and to assess this medium when used with Petrifilm™ AC plates. For this purpose, Bifidobacterium spp., Lactobacillus spp. and Streptococcus thermophilus strains were tested to verify their fermentation patterns for different carbohydrates. All bifidobacteria strains were able to use raffinose. Based on these characteristic, a selective culture medium was proposed (Raffinose-Propionate Lithium Mupirocin, RP-MUP), used with Petrifilm™ AC plates, and was used to enumerate bifidobacteria in fermented milk. RP-MUP performance was assessed by comparing the results with this medium to reference protocols and culture media for bifidobacteria enumeration. RP-MUP, whether used or not with Petrifilm™ AC, presented similar performance to TOS-MUP (ISO 29981), with no significant differences between the mean bifidobacteria counts (p < 0.05) and with high correlation indices (r = 0.99, p < 0.05). As an advantage, reliable results were obtained after just 48 h of incubation when RP-MUP was used with Petrifilm™ AC, instead of the 72 h described in the ISO 29981 protocol.
authors.affiliation: Departamento de Veterinária, Universidade Federal de Viçosa, Campus UFV, 36570 000 Viçosa, MG, Brazil.
authors.forename: Rodrigo Otávio
authors.initials: RO
authors.lastname: Miranda
authors.affiliation: Departamento de Tecnologia de Alimentos, Universidade Federal de Viçosa, Campus UFV, Viçosa, MG 36570 000, Brazil.
authors.forename: Antonio Fernandes
authors.initials: AF
authors.lastname: de Carvalho
authors.affiliation: Departamento de Veterinária, Universidade Federal de Viçosa, Campus UFV, 36570 000 Viçosa, MG, Brazil. Electronic address: nero@ufv.br.
authors.forename: Luís Augusto
authors.initials: LA
authors.lastname: Nero
mesh_terms: D000818:Animals; D001644:Bifidobacterium / Q000254:growth & development* / Q000378:metabolism; D002417:Cattle; D003470:Culture Media / Q000737:chemistry* / Q000378:metabolism; D046508:Culture Techniques / Q000295:instrumentation / Q000379:methods*; D043302:Cultured Milk Products / Q000382:microbiology*; D005285:Fermentation; D008094:Lithium / Q000378:metabolism; D016712:Mupirocin / Q000378:metabolism; D011422:Propionates / Q000378:metabolism; D011887:Raffinose / Q000378:metabolism
chemical_list: D003470:Culture Media; D011422:Propionates; D008094:Lithium; D016712:Mupirocin; D011887:Raffinose
keywords: Bifidobacteria; Petrifilm™ AC; RP-MUP; Selective enumeration; TOS-MUP