title: The lactic acid bacteria and yeast microbiota of eighteen sourdoughs used for the manufacture of traditional Italian sweet leavened baked goods.
abstract: The lactic acid bacteria and yeast microbiota of eighteen sourdoughs used for the manufacture of some traditional Italian sweet leavened baked goods were studied through culture-dependent method and pyrosequencing. Flours used for back slopping and sourdoughs were also biochemically characterized. Principal component analysis was applied to explore eventual correlations between process parameters applied during back slopping, some flour nutrients, profile of microbiota, and biochemical characteristics of sourdoughs. The median values of the cell density of lactic acid bacteria and yeasts were 8.05 and 7.03 log CFU/g, respectively. As shown by culture-dependent method, Lactobacillus sanfranciscensis was identified in all the sourdoughs, except for Panaredda and Torcolo di San Costanzo. For eleven sourdoughs, all the lactic acid bacteria isolates were allotted to this species. For Buccellato di Lucca, Mbriagotto, Pandoro, and Nadalin sourdoughs, at least 80% of the isolates was allotted to this species. Other lactic acid bacteria isolated with a relatively high frequence were Lactobacillus plantarum and Leuconostoc citreum. Pyrosequencing confirmed and complemented the culture-dependent approach, detecting L. sanfranciscensis also in Panaredda and Torcolo di San Costanzo sourdoughs. Saccharomyces cerevisiae was identified in all the sourdoughs, except for Mbriagotto, Ciambella di Mosto and Pandolce Genovese. These latter sourdoughs harbored strains of Candida humilis, whereas five sourdoughs combined the presence of both yeast species. Positive correlations were found between time of back slopping and cell density and main metabolites of lactic acid bacteria. Percentage of sourdough used as inoculum was mainly correlated with the cell density of yeasts and the concentration of ethanol. This study provided a comprehensive and comparative approach to highlight the dominant microbiota of Italian sourdoughs, which could be exploited further to guarantee a highly reproducible quality of the Italian sweet goods studied, while preserving their traditional trait.
authors.affiliation: Department of Scienze del Suolo, della Pianta e degli Alimenti, University of Bari Aldo Moro, via Amendola 165/a., Bari, 70126, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Lattanzi
authors.forename: Fabio
authors.initials: F
authors.lastname: Minervini
authors.forename: Raffaella
authors.initials: R
authors.lastname: Di Cagno
authors.forename: Annamaria
authors.initials: A
authors.lastname: Diviccaro
authors.forename: Livio
authors.initials: L
authors.lastname: Antonielli
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Cardinali
authors.forename: Stefan
authors.initials: S
authors.lastname: Cappelle
authors.forename: Maria
authors.initials: M
authors.lastname: De Angelis
authors.forename: Marco
authors.initials: M
authors.lastname: Gobbetti
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D018407:Bacterial Physiological Phenomena; D005285:Fermentation; D005511:Food Handling; D005516:Food Microbiology; D007778:Lactobacillus / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology; D054892:Metagenome / Q000235:genetics / Q000502:physiology*; D025341:Principal Component Analysis; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D015003:Yeasts / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*