scholarly journals Influence of Artisan Bakery- or Laboratory-Propagated Sourdoughs on the Diversity of Lactic Acid Bacterium and Yeast Microbiotas

2012 ◽  
Vol 78 (15) ◽  
pp. 5328-5340 ◽  
Author(s):  
Fabio Minervini ◽  
Anna Lattanzi ◽  
Maria De Angelis ◽  
Raffaella Di Cagno ◽  
Marco Gobbetti

ABSTRACTSeven mature type I sourdoughs were comparatively back-slopped (80 days) at artisan bakery and laboratory levels under constant technology parameters. The cell density of presumptive lactic acid bacteria and related biochemical features were not affected by the environment of propagation. On the contrary, the number of yeasts markedly decreased from artisan bakery to laboratory propagation. During late laboratory propagation, denaturing gradient gel electrophoresis (DGGE) showed that the DNA band corresponding toSaccharomyces cerevisiaewas no longer detectable in several sourdoughs. Twelve species of lactic acid bacteria were variously identified through a culture-dependent approach. All sourdoughs harbored a certain number of species and strains, which were dominant throughout time and, in several cases, varied depending on the environment of propagation. As shown by statistical permutation analysis, the lactic acid bacterium populations differed among sourdoughs propagated at artisan bakery and laboratory levels.Lactobacillus plantarum,Lactobacillus sakei, andWeissella cibariadominated in only some sourdoughs back-slopped at artisan bakeries, andLeuconostoc citreumseemed to be more persistent under laboratory conditions. Strains ofLactobacillus sanfranciscensiswere indifferently found in some sourdoughs. Together with the other stable species and strains, other lactic acid bacteria temporarily contaminated the sourdoughs and largely differed between artisan bakery and laboratory levels. The environment of propagation has an undoubted influence on the composition of sourdough yeast and lactic acid bacterium microbiotas.

2013 ◽  
Vol 79 (24) ◽  
pp. 7827-7836 ◽  
Author(s):  
Danilo Ercolini ◽  
Erica Pontonio ◽  
Francesca De Filippis ◽  
Fabio Minervini ◽  
Antonietta La Storia ◽  
...  

ABSTRACTThe bacterial ecology during rye and wheat sourdough preparation was described by 16S rRNA gene pyrosequencing. Viable plate counts of presumptive lactic acid bacteria, the ratio between lactic acid bacteria and yeasts, the rate of acidification, a permutation analysis based on biochemical and microbial features, the number of operational taxonomic units (OTUs), and diversity indices all together demonstrated the maturity of the sourdoughs during 5 to 7 days of propagation. Flours were mainly contaminated by metabolically active genera (Acinetobacter,Pantoea,Pseudomonas,Comamonas,Enterobacter,Erwinia, andSphingomonas) belonging to the phylumProteobacteriaorBacteroidetes(genusChryseobacterium). Their relative abundances varied with the flour. Soon after 1 day of propagation, this population was almost completely inhibited except for theEnterobacteriaceae. Although members of the phylumFirmicuteswere present at very low or intermediate relative abundances in the flours, they became dominant soon after 1 day of propagation. Lactic acid bacteria were almost exclusively representative of theFirmicutesby this time.Weissellaspp. were already dominant in rye flour and stably persisted, though they were later flanked by theLactobacillus sakeigroup. There was a succession of species during 10 days of propagation of wheat sourdoughs. The fluctuation between dominating and subdominating populations ofL. sakeigroup,Leuconostocspp.,Weissellaspp., andLactococcus lactiswas demonstrated. Other subdominant species such asLactobacillus plantarumwere detectable throughout propagation. As shown by PCR-denaturing gradient gel electrophoresis (PCR-DGGE) analysis,Saccharomyces cerevisiaedominated throughout the sourdough propagation. Notwithstanding variations due to environmental and technology determinants, the results of this study represent a clear example of how the microbial ecology evolves during sourdough preparation.


2003 ◽  
Vol 69 (4) ◽  
pp. 2321-2329 ◽  
Author(s):  
Olimpia Pepe ◽  
Giuseppe Blaiotta ◽  
Giancarlo Moschetti ◽  
Teresa Greco ◽  
Francesco Villani

ABSTRACT Two types of white wheat bread (high- and low-type loaves) were investigated for rope spoilage. Thirty of the 56 breads tested developed rope spoilage within 5 days; the high-type loaves were affected by rope spoilage more than the low-type loaves. Sixty-one Bacillus strains were isolated from ropy breads and were characterized on the basis of their phenotypic and genotypic traits. All of the isolates were identified as Bacillus subtilis by biochemical tests, but molecular assays (randomly amplified polymorphic DNA PCR assay, denaturing gradient gel electrophoresis analysis, and sequencing of the V3 region of 16S ribosomal DNA) revealed greater Bacillus species variety in ropy breads. In fact, besides strains of B. subtilis, Bacillus licheniformis, Bacillus cereus, and isolates of Bacillus clausii and Bacillus firmus were also identified. All of the ropy Bacillus isolates exhibited amylase activity, whereas only 32.4% of these isolates were able to produce ropiness in bread slices after treatment at 96°C for 10 min. Strains of lactic acid bacteria previously isolated from sourdough were first selected for antirope activity on bread slices and then used as starters for bread-making experiments. Prevention of growth of approximately 104 rope-producing B. subtilis G1 spores per cm2 on bread slices for more than 15 days was observed when heat-treated cultures of Lactobacillus plantarum E5 and Leuconostoc mesenteroides A27 were added. Growth of B. subtilis G1 occurred after 7 days in breads started with Saccharomyces cerevisiae T22, L. plantarum E5, and L. mesenteroides A27.


2008 ◽  
Vol 75 (4) ◽  
pp. 1099-1109 ◽  
Author(s):  
Sonya Siragusa ◽  
Raffaella Di Cagno ◽  
Danilo Ercolini ◽  
Fabio Minervini ◽  
Marco Gobbetti ◽  
...  

ABSTRACTThe structure and stability of the dominant lactic acid bacterium population were assessed during wheat flour sourdough type I propagation by using singly nine strains ofLactobacillus sanfranciscensis. Under back-slopping propagation with wheat flour type 0 F114, cell numbers of presumptive lactic acid bacteria varied slightly between and within starters. As determined by randomly amplified polymorphic DNA-PCR and restriction endonuclease analysis-pulsed-field gel electrophoresis analyses, only three (LS8, LS14, and LS44) starters dominated throughout 10 days of propagation. The others progressively decreased to less than 3 log CFU g−1. Partial sequence analysis of the 16S rRNA andrecAgenes and PCR-denaturating gradient gel electrophoresis analysis using therpoBgene allowed identification ofWeissella confusa,Lactobacillus sanfranciscensis,Lactobacillus plantarum,Lactobacillus rossiae,Lactobacillus brevis,Lactococcus lactissubsp.lactis,Pediococcus pentosaceus, andLactobacillusspp. as the dominant species of the raw wheat flour. At the end of propagation, one autochthonous strain ofL. sanfranciscensiswas found in all the sourdoughs. Except forL. brevis, strains of the above species were variously found in the mature sourdoughs. Persistent starters were found in association with other biotypes ofL. sanfranciscensisand withW. confusaorL. plantarum. Sourdoughs were characterized for acidification, quotient of fermentation, free amino acids, and community-level catabolic profiles by USING Biolog 96-well Eco microplates. In particular, catabolic profiles of sourdoughs containing persistent starters behaved similarly and were clearly differentiated from the others. The three persistent starters were further used for the production of sourdoughs and propagated by using another wheat flour whose lactic acid bacterium population in part differed from the previous one. Also, in this case all three starter strains persisted during propagation.


2017 ◽  
Vol 5 (1) ◽  
pp. 22
Author(s):  
Yusuf BİÇER ◽  
Gürkan UÇAR

Lactic acid bacteria (LAB) are an important group in the industrially using microorganisms. The first pure cultures of bacteria was "Bacterium lactis" (probably Lactococcus lactis), obtained in 1873 by J. Lister. LAB are Gram-positive, non motile, non spore-forming, except Sporolactobacillus inulinus, catalase negative, microaerophilic or anaerobic microorganisms. LAB can be found in milk and dairy products, plants and human and animal intestinal mucosa. LAB have low Guanine and Cytosine (G+C) ratio.The industrial applications of lactic acid bacteria is considered, it is emphasized that reliable typing methods in strain levels are getting important about both study on cultures used in functional foods and determining the performance of LAB starter cultures. Denaturing Gradient Gel Electrophoresis (DGGE) is the most common technique in molecular fingerprinting culture-independent techniques. The technique is based on the separation of the same length but having different sequences of the Polymerase Chain Reaction (PCR) products. 


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