title: Codominance of Lactobacillus plantarum and obligate heterofermentative lactic acid bacteria during sourdough fermentation.
abstract: Fifteen sourdoughs produced in western Sicily (southern Italy) were analysed by classical methods for their chemico-physical characteristics and the levels of lactic acid bacteria (LAB). pH and total titratable acidity (TTA) were mostly in the range commonly reported for similar products produced in Italy, but the fermentation quotient (FQ) of the majority of samples was above 4.0, due to the low concentration of acetic acid estimated by high performance liquid chromatography (HPLC). Specific counts of LAB showed levels higher than 10(8) CFU g(-1) for many samples. The colonies representing various morphologies were isolated and, after the differentiation based on phenotypic characteristics, divided into 10 groups. The most numerous group was composed of facultative heterofermentative isolates, indicating a relevance of this bacterial group during fermentation. The genetic analysis by randomly amplified polymorphic DNA (RAPD)-PCR, 16S rRNA gene sequencing and species-specific PCRs identified 33 strains as Lactobacillus plantarum, Lactobacillus curvatus and Lactobacillus graminis. Due to the consistent presence of L. plantarum, it was concluded that this species codominates with obligate heterofermentative LAB in sourdough production in this geographical area. In order to evaluate the performances at the basis of their fitness, the 29 L. plantarum strains were investigated for several technological traits. Twelve cultures showed good acidifying abilities in vitro and L. plantarum PON100148 produced the highest concentrations of organic acids. Eleven strains were positive for extracellular protease activity. Bacteriocin-like inhibitory substances (BLIS) production and antifungal activity was scored positive for several strains, included L. plantarum PON100148 which was selected as starter for experimental sourdough production. The characteristics of the sourdoughs and the resulting breads indicated that the best productions were obtained in presence of L. plantarum PON100148.
authors.affiliation: Dipartimento Scienze Agrarie e Forestali, Università degli Studi di Palermo, Viale delle Scienze 4, 90128 Palermo, Italy.
authors.forename: Giusi
authors.initials: G
authors.lastname: Ventimiglia
authors.affiliation: Dipartimento Scienze Agrarie e Forestali, Università degli Studi di Palermo, Viale delle Scienze 4, 90128 Palermo, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Alfonzo
authors.affiliation: Istituto Zooprofilattico Sperimentale della Sicilia "A. Mirri", Via G. Marinuzzi 4, Palermo, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Galluzzo
authors.affiliation: Dipartimento Scienze Agrarie e Forestali, Università degli Studi di Palermo, Viale delle Scienze 4, 90128 Palermo, Italy.
authors.forename: Onofrio
authors.initials: O
authors.lastname: Corona
authors.affiliation: Dipartimento Scienze Agrarie e Forestali, Università degli Studi di Palermo, Viale delle Scienze 4, 90128 Palermo, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Francesca
authors.affiliation: Istituto Zooprofilattico Sperimentale della Sicilia "A. Mirri", Via G. Marinuzzi 4, Palermo, Italy.
authors.forename: Santo
authors.initials: S
authors.lastname: Caracappa
authors.affiliation: Dipartimento Scienze Agrarie e Forestali, Università degli Studi di Palermo, Viale delle Scienze 4, 90128 Palermo, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Moschetti
authors.affiliation: Dipartimento Scienze Agrarie e Forestali, Università degli Studi di Palermo, Viale delle Scienze 4, 90128 Palermo, Italy. Electronic address: luca.settanni@unipa.it.
authors.forename: Luca
authors.initials: L
authors.lastname: Settanni
mesh_terms: D019342:Acetic Acid / Q000032:analysis; D001430:Bacteriocins; D001939:Bread / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D005285:Fermentation; D005516:Food Microbiology; D056084:Genetic Fitness; D007558:Italy; D019344:Lactic Acid / Q000378:metabolism; D007778:Lactobacillus / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000502:physiology*; D048191:Lactiplantibacillus plantarum / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D056265:Microbial Interactions; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique
chemical_list: D001430:Bacteriocins; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D019344:Lactic Acid; D019342:Acetic Acid
keywords: Bacterial codominance; Lactic acid bacteria; Lactobacillus plantarum; Sourdough; Starter selection