6533b7dcfe1ef96bd1271e67
RESEARCH PRODUCT
Identification, typing, and investigation of the dairy characteristics of lactic acid bacteria isolated from 'Vastedda della valle del Belìce' cheese
Raimondo GaglioLuca SettanniRosa GuarcelloNicola FrancescaBaldassare PortolanoMargherita CruciataRosalia Di GerlandoGiancarlo Moschettisubject
Streptococcus thermophiluseducation.field_of_studyAcidifying capacitybiologyBacteriocinLactococcusPopulationLactococcus lactisAcidifying capacity; Bacteriocins; Diacetyl; Lactic acid bacteria; Raw ewes’ milk cheesefood and beveragesDiacetylbiology.organism_classificationRaw ewes’ milk cheeseBiochemistryMicrobiologySettore AGR/17 - Zootecnica Generale E Miglioramento GeneticoEnterococcusLeuconostoc mesenteroidesLactobacillusLactic acid bacteriaLeuconostoceducationFood ScienceSettore AGR/16 - Microbiologia Agrariadescription
Traditional cheeses made without starter cultures can be characterised by the attribute of instability. The addition of autochthonous starter cultures can ensure stability without compromising the characteristics of the final product. This study aimed to characterise the autochthonous lactic acid bacteria (LAB) population in “Vastedda della valle del Belice” cheeses, which have a protected designation of origin (PDO) status, in order to develop an ad hoc starter culture to be used in its future production. Winter and spring productions were analysed to ensure isolation of specific LAB that had adapted to perform fermentation at low temperatures. Plate counts revealed total microbial numbers nearing 109 CFU.g−1. All of the cheese samples were dominated by coccus-shaped LAB. When enterobacteria were present, their concentrations were at similar levels (3.3–5.6 Log CFU.g−1) in both seasons. All of the colonies that differed in morphological appearance were isolated and differentiated on the basis of phenotypic characteristics and genetic polymorphisms, as analysed by random amplification of polymorphic DNA-polymerase chain reaction. A total of 74 strains were identified and further genotyped by sequencing the 16S rRNA gene, resulting in the identification of 16 LAB species belonging to five genera (Enterococcus, Lactobacillus, Lactococcus, Leuconostoc and Streptococcus). The species most frequently present were Streptococcus gallolyticus subsp. macedonicus, Streptococcus thermophilus, Lactococcus lactis and Leuconostoc mesenteroides. The 74 strains were also investigated in vitro for general dairy parameters such as acidification capacity, diacetyl generation and antibacterial activity. Several strains of the most frequently represented species displayed traits relevant to the production of PDO “Vastedda della valle del Belice”.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2013-10-11 |