title: Diversity and technological potential of lactic acid bacteria of wheat flours.
abstract: Lactic acid bacteria (LAB) were analysed from wheat flours used in traditional bread making throughout Sicily (southern Italy). Plate counts, carried out in three different media commonly used to detect food and sourdough LAB, revealed a maximal LAB concentration of approximately 4.75 Log CFU g(-1). Colonies representing various morphological appearances were isolated and differentiated based on phenotypic characteristics and genetic analysis by randomly amplified polymorphic DNA (RAPD)-PCR. Fifty unique strains were identified. Analysis by 16S rRNA gene sequencing grouped the strains into 11 LAB species, which belonged to six genera: Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and Weissella. Weissella cibaria, Lactobacillus plantarum, Leuconostoc pseudomesenteroides and Leuconostoc citreum were the most prevalent species. The strains were not geographically related. Denaturing gradient gel electrophoresis (DGGE) analysis of total DNA of flour was used to provide a more complete understanding of the LAB population; it confirmed the presence of species identified with the culture-dependent approach, but did not reveal the presence of any additional LAB species. Finally, the technological characteristics (acidifying capacity, antimicrobial production, proteolytic activity, organic acid, and volatile organic compound generation) of the 50 LAB strains were investigated. Eleven strains were selected for future in situ applications.
authors.affiliation: Department of Agricultural and Forestry Science, University of Palermo, Palermo, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Alfonzo
authors.forename: Giusi
authors.initials: G
authors.lastname: Ventimiglia
authors.forename: Onofrio
authors.initials: O
authors.lastname: Corona
authors.forename: Rosalia
authors.initials: R
authors.lastname: Di Gerlando
authors.forename: Raimondo
authors.initials: R
authors.lastname: Gaglio
authors.forename: Nicola
authors.initials: N
authors.lastname: Francesca
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Moschetti
authors.forename: Luca
authors.initials: L
authors.lastname: Settanni
mesh_terms: D000143:Acids / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D044822:Biodiversity; D005433:Flour / Q000382:microbiology*; D007218:Industrial Microbiology; D019344:Lactic Acid / Q000378:metabolism; D007777:Lactobacillaceae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism; D010802:Phylogeny; D014908:Triticum / Q000382:microbiology*
chemical_list: D000143:Acids; D001426:Bacterial Proteins; D019344:Lactic Acid; D010447:Peptide Hydrolases
keywords: Acidification; Lactic acid bacteria; Proteolysis; Sourdough; Volatile organic compounds; Wheat flour