scholarly journals Lactic acid bacteria and identification with PCR-DGGE

2017 ◽  
Vol 5 (1) ◽  
pp. 22
Author(s):  
Yusuf BİÇER ◽  
Gürkan UÇAR
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Industrial Applications ◽  
Starter Cultures ◽  
Molecular Fingerprinting ◽  
Anaerobic Microorganisms ◽  
Culture Independent ◽  
Gradient Gel Electrophoresis ◽  
Pure Cultures

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. 

scholarly journals Microbial Ecology Dynamics during Rye and Wheat Sourdough Preparation

2013 ◽  
Vol 79 (24) ◽  
pp. 7827-7836 ◽  
Author(s):  
Danilo Ercolini ◽  
Erica Pontonio ◽  
Francesca De Filippis ◽  
Fabio Minervini ◽  
Antonietta La Storia ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Microbial Ecology ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Diversity Indices ◽  
Rrna Gene ◽  
Content Type ◽  
Gradient Gel Electrophoresis ◽  
Plate Counts ◽  
Relative Abundances

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.

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
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactic Acid Bacterium ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Type I ◽  
Content Type ◽  
Stable Species ◽  
Mature Type ◽  
Gradient Gel Electrophoresis ◽  
Permutation Analysis

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.

scholarly journals Polyphasic Study of the Spatial Distribution of Microorganisms in Mexican Pozol, a Fermented Maize Dough, Demonstrates the Need for Cultivation-Independent Methods To Investigate Traditional Fermentations

1999 ◽  
Vol 65 (12) ◽  
pp. 5464-5473 ◽  
Author(s):  
Frédéric Ampe ◽  
Nabil ben Omar ◽  
Claire Moizan ◽  
Carmen Wacher ◽  
Jean-Pierre Guyot
Keyword(s):  
Lactic Acid ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Fermented Food ◽  
Fermented Foods ◽  
Product Analysis ◽  
Culture Independent ◽  
Gradient Gel Electrophoresis ◽  
Traditional Fermented Foods

ABSTRACT The distribution of microorganisms in pozol balls, a fermented maize dough, was investigated by a polyphasic approach in which we used both culture-dependent and culture-independent methods, including microbial enumeration, fermentation product analysis, quantification of microbial taxa with 16S rRNA-targeted oligonucleotide probes, determination of microbial fingerprints by denaturing gradient gel electrophoresis (DGGE), and 16S ribosomal DNA gene sequencing. Our results demonstrate that DGGE fingerprinting and rRNA quantification should allow workers to precisely and rapidly characterize the microbial assemblage in a spontaneous lactic acid fermented food. Lactic acid bacteria (LAB) accounted for 90 to 97% of the total active microflora; no streptococci were isolated, although members of the genus Streptococcus accounted for 25 to 50% of the microflora. Lactobacillus plantarum and Lactobacillus fermentum, together with members of the generaLeuconostoc and Weissella, were the other dominant organisms. The overall activity was more important at the periphery of a ball, where eucaryotes, enterobacteria, and bacterial exopolysacharide producers developed. Our results also showed that the metabolism of heterofermentative LAB was influenced in situ by the distribution of the LAB in the pozol ball, whereas homolactic fermentation was controlled primarily by sugar limitation. We propose that starch is first degraded by amylases from LAB and that the resulting sugars, together with the lactate produced, allow a secondary flora to develop in the presence of oxygen. Our results strongly suggest that cultivation-independent methods should be used to study traditional fermented foods.

scholarly journals Rope-Producing Strains of Bacillus spp. from Wheat Bread and Strategy for Their Control by Lactic Acid Bacteria

2003 ◽  
Vol 69 (4) ◽  
pp. 2321-2329 ◽  
Author(s):  
Olimpia Pepe ◽  
Giuseppe Blaiotta ◽  
Giancarlo Moschetti ◽  
Teresa Greco ◽  
Francesco Villani
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Wheat Bread ◽  
Bread Making ◽  
Biochemical Tests ◽  
White Wheat ◽  
Heat Treated ◽  
Bacillus Spp ◽  
Gradient Gel Electrophoresis

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.

scholarly journals Nutritional Properties and Antinutritional Factors of Corn Paste (Kutukutu) Fermented by Different Strains of Lactic Acid Bacteria

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Tchikoua Roger ◽  
Tatsadjieu Ngouné Léopold ◽  
Mbofung Carl Moses Funtong
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Protein Content ◽  
Starch Content ◽  
Principal Component ◽  
Lactobacillus Brevis ◽  
Antinutritional Factors ◽  
Starter Cultures ◽  
Nutritional Properties ◽  
Pure Cultures

The aim of this study is to reduce antinutritional factors and to improve the nutritional properties ofKutukutuduring fermentation with Lactic Acid Bacteria (LAB). For that,Kutukutu(700 g) was prepared in the laboratory and inoculated with pure cultures of LAB (109 CFU/mL). Then, preparation was incubated for 120 h. Every 24 h,Kutukutuwere collected, dried at 45°C for 24 h, and analyzed. The results showed thatLactobacillus brevisG25 increased reducing sugars content to 80.7% inKutukutuafter 96 h of fermentation.Lactobacillus fermentumN33 reduced the starch content to 73.2%, whileLactobacillus brevisG11,L. brevisG25, andLactobacillus cellobiosusM41 rather increased the protein content to 18.9%. The bioavailability of Mg and Fe increased, respectively, to 50.5% and 70.6% in theKutukutufermented withL. brevisG25.L. plantarumA6 reduced the tannin content to 98.8% andL. buchneriM11 reduced the phytate content to 95.5%. The principal component analysis (PCA) shows that, for a best reduction of antinutrients factors and improvement of protein content and minerals,Kutukutumust be fermented byL. brevisG25 andL. fermentumN33, respectively. These starter cultures could be used to ameliorate nutritional proprieties ofKutukutuduring the fermentation.

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