Molecular identification and typing of lactic acid bacteria associated with the production of two artisanal raw milk cheeses

Abstract

-A polyphasic approach was used to evaluate the diversity and persistence of lactic acid bacteria (LAB) strains during the production and ripening of two Flemish artisanal raw milk Goudatype cheeses, Bellie and Dulses. During two consecutive productions with a one-month interval, samples of milk, starter, curd and cheese at various ripening times were sampled for conventional culturing using four different selective media. The resulting set of 734 isolates was identified using (GTG) 5 -PCR fingerprinting and sequence analysis of the 16S rRNA and pheS genes. Isolated LAB mainly consisted of Lactobacillus paracasei, Lactococcus lactis subsp. lactis, Lactobacillus plantarum, Pediococcus pentosaceus, Lactobacillus brevis, Lactobacillus rhamnosus, Lactobacillus curvatus, Enterococcus faecalis, Enterococcus durans and Lactobacillus perolens. A combined typing approach including (GTG) 5 -PCR and amplified fragment length polymorphism (AFLP) analysis revealed the presence of a Lc. lactis subsp. lactis isolate of the starter in ripened cheese at eight weeks and the persistence of several other LAB strains throughout the two successive production batches. Possibly, a number of these strains are autochthonous members of the microbial cheese production environment that play an important role in the development of the sensory properties of the cheese.

Genetic polymorphism of lactic acid bacteria isolated from “Pirot ‘ironed’ sausage” from Serbia

“…Thus, PCR amplification of repetitive bacterial DNA elements (rep-PCR) is recognized as a simple PCR-based technique with a high discriminatory power and low cost and it is used for classifying and typing a wide range of Gram-negative and several Gram-positive bacteria [8]. Rep-PCR fingerprinting methods can give comparative results, even when using only one primer, such as GTG 5 , which was proven to be one of the best elements for Lactobacillus determination [2,8,10,12]. On the other hand, RAPD requires the use of more than one primer for strain characterization in most cases [13].…”

Technological, phenotypic and genotypic characterisation of wild lactic acid bacteria involved in the production of Bitto PDO Italian cheese

“…It is well-known that the typicality of raw milk cheeses is linked mainly to nonstarter lactic acid bacteria (NSLAB) originating from raw milk (Van Hoorde et al 2008a). Thus, the biodiversity of the lactic acid bacteria (LAB) involved in raw milk cheese production is considered to be a fundamental factor for the features and quality of these artisanal products.…”

Phenotypic and genotypic characterization of lactic acid bacteria isolated from cow, ewe and goat dairy artisanal farmhouses

“…Although, phenotypic tests provide evidence for different metabolic capabilities among isolates, the complex and sometimes graded differences make distinctions difficult. Designation of certain new type strains based solely on phenotypic characteristics has resulted in ambiguities which have ultimately been resolved using molecular techniques ( Van Hoorde et al , 2008 ). The aim of the present study is to use a polyphasic approach to identify selected strains of LAB isolated from raw milk, cheese and cheese whey starter by characterization of phenotype, amplified ribosomal DNA restriction analysis (ARDRA) and 16S rDNA sequence analysis.…”