scholarly journals Technological and Safety Attributes of Lactic Acid Bacteria and Yeasts Isolated from Spontaneously Fermented Greek Wheat Sourdoughs

2021 ◽  
Vol 9 (4) ◽  
pp. 671
Author(s):  
Maria K. Syrokou ◽  
Sofia Tziompra ◽  
Eleni-Efthymia Psychogiou ◽  
Sofia-Despoina Mpisti ◽  
Spiros Paramithiotis ◽  
...  

The aim of the present study was to assess the technological and safety potential of 207 lactic acid bacteria (LAB) and 195 yeast strains isolated from spontaneously fermented Greek wheat sourdoughs. More accurately, the amylolytic, proteolytic, lipolytic, phytase and amino acid decarboxylase activities, along with the production of exopolysaccharides and antimicrobial compounds by the LAB and yeast isolates, were assessed. A well diffusion assay revealed seven proteolytic LAB and eight yeast strains; hydrolysis of tributyrin was evident only in 11 LAB strains. A further Sodium Dodecyl Sulphate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) indicated partial hydrolysis of gluten. Lipolysis kinetics over 21 days was applied, exhibiting that lipolytic activity ranged from 6.25 to 65.50 AU/mL. Thirteen LAB inhibited Penicillium olsonii and Aspergillus niger growth and 12 yeast strains inhibited Pe. chrysogenum growth. Twenty-one Lactiplantibacillus plantarum strains exhibited inhibitory activity against Listeria monocytogenes, as well as several sourdough-associated isolates. The structural gene encoding plantaricin 423 was detected in 19 Lcb. plantarum strains, while the structural genes encoding plantaricins NC8, PlnE/F, PlnJ/K, and S were detected in two Lcb. plantarum strains. None of the microbial strains tested exhibited exopolysaccharide (EPS) production, amino acid decarboxylase, amylolytic or phytase activity. The technological and safety potential of the Lcb. plantarum and Wickerhamomyces anomalus strains was highlighted, since some of them exhibited proteolytic, lipolytic, antibacterial and antimould activities.

2015 ◽  
Vol 83 (1) ◽  
pp. 115-124 ◽  
Author(s):  
Fabricio L Tulini ◽  
Nolwenn Hymery ◽  
Thomas Haertlé ◽  
Gwenaelle Le Blay ◽  
Elaine C P De Martinis

Lactic acid bacteria (LAB) can be isolated from different sources such as milk and cheese, and the lipolytic, proteolytic and glycolytic enzymes of LAB are important in cheese preservation and in flavour production. Moreover, LAB produce several antimicrobial compounds which make these bacteria interesting for food biopreservation. These characteristics stimulate the search of new strains with technological potential. From 156 milk and cheese samples from cow, buffalo and goat, 815 isolates were obtained on selective agars for LAB. Pure cultures were evaluated for antimicrobial activities by agar antagonism tests and for proteolytic activity on milk proteins by cultivation on agar plates. The most proteolytic isolates were also tested by cultivation in skim milk followed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the fermented milk. Among the 815 tested isolates, three of them identified asStreptococcus uberis(strains FT86, FT126 and FT190) were bacteriocin producers, whereas four other ones identified asWeissella confusaFT424,W. hellenicaFT476,Leuconostoc citreumFT671 andLactobacillus plantarumFT723 showed high antifungal activity in preliminary assays. Complementary analyses showed that the most antifungal strain wasL. plantarumFT723 that inhibitedPenicillium expansumin modified MRS agar (De Man, Rogosa, Sharpe, without acetate) and fermented milk model, however no inhibition was observed againstYarrowia lipolytica. The proteolytic capacities of three highly proteolytic isolates identified asEnterococcus faecalis(strains FT132 and FT522) andLactobacillus paracaseiFT700 were confirmed by SDS–PAGE, as visualized by the digestion of caseins and whey proteins (β-lactoglobulin and α-lactalbumin). These results suggest potential applications of these isolates or their activities (proteolytic activity or production of antimicrobials) in dairy foods production.


1988 ◽  
Vol 252 (2) ◽  
pp. 331-335 ◽  
Author(s):  
I Nishigaki ◽  
H Ichinose ◽  
K Tamai ◽  
T Nagatsu

Aromatic L-amino acid decarboxylase was purified from bovine brain for the first time by affinity chromatography using a monoclonal antibody to the enzyme, and it was compared with the decarboxylase purified from bovine adrenal medulla by the same procedure. The monoclonal antibody was produced from a hybridoma established for the enzyme highly purified from bovine adrenal medulla. The Mr values of brain and adrenal-medulla enzyme were both estimated to be approx. 100,000 by gel-permeation chromatography. SDS/polyacrylamide-gel electrophoresis revealed a single band with an apparent Mr of 50,000. Western immunoblot analysis showed that the antibody recognized each enzyme. With regard to substrate specificity, pH-dependence and effect of pyridoxal 5′-phosphate as a cofactor, both enzymes were similar.


2021 ◽  
Vol 71 (4) ◽  
pp. 2553
Author(s):  
Y. N. DOĞAN ◽  
Ö. F. LENGER ◽  
M. DÜZ ◽  
I. DOĞAN ◽  
Z. GÜRLER

Biogenic amines (BAs) are formed by the decarboxylation of amino acids in fermented products and accumulate in these products due to the fermentation conditions, the natural microflora of the product, and the diversity of amino acids. Although they are inhibited by the human body, they are a hazard to public health. Starter cultures used in fermented sucuk should not have amino acid decarboxylase properties. The aim of the present study was to determine proteolytic activity, histidine and tyrosine decarboxylase enzyme activities of Lactobacillus plantarum, Lactobacillus sake, and Lactobacillus curvatus species and to evaluate the level of BA in sucuk groups containing these lactic acid bacteria (LAB). It was determined that none of the LAB generated these activities. While histamine values were not statistically significant in the sucuk groups (P> 0.05), tyramine values showed statistically significant differences (P<0.05). The tyramine values of GI ( = 1.43 ± 0.75) and GIII ( = 2.73 ± 1.02) groups were lower than C ( = 8.97 ± 5.29) and GII ( = 7.58 ± 2.90) groups. According to the results of the study, L. plantarum or L. curvatus can provide more reliable fermented products with respect to tyramine formation. L. plantarum, L. sake, and L. curvatus could reduce histamine and tyramine formation in fermented sucuk.


2002 ◽  
Vol 68 (12) ◽  
pp. 6059-6069 ◽  
Author(s):  
Luc De Vuyst ◽  
Vincent Schrijvers ◽  
Spiros Paramithiotis ◽  
Bart Hoste ◽  
Marc Vancanneyt ◽  
...  

ABSTRACT Lactic acid bacteria (LAB) were isolated from Greek traditional wheat sourdoughs manufactured without the addition of baker's yeast. Application of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of total cell protein, randomly amplified polymorphic DNA-PCR, DNA-DNA hybridization, and 16S ribosomal DNA sequence analysis, in combination with physiological traits such as fructose fermentation and mannitol production, allowed us to classify the isolated bacteria into the species Lactobacillus sanfranciscensis, Lactobacillus brevis, Lactobacillus paralimentarius, and Weissella cibaria. This consortium seems to be unique for the Greek traditional wheat sourdoughs studied. Strains of the species W. cibaria have not been isolated from sourdoughs previously. No Lactobacillus pontis or Lactobacillus panis strains were found. An L. brevis-like isolate (ACA-DC 3411 t1) could not be identified properly and might be a new sourdough LAB species. In addition, fermentation capabilities associated with the LAB detected have been studied. During laboratory fermentations, all heterofermentative sourdough LAB strains produced lactic acid, acetic acid, and ethanol. Mannitol was produced from fructose that served as an additional electron acceptor. In addition to glucose, almost all of the LAB isolates fermented maltose, while fructose as the sole carbohydrate source was fermented by all sourdough LAB tested except L. sanfranciscensis. Two of the L. paralimentarius isolates tested did not ferment maltose; all strains were homofermentative. In the presence of both maltose and fructose in the medium, induction of hexokinase activity occurred in all sourdough LAB species mentioned above, explaining why no glucose accumulation was found extracellularly. No maltose phosphorylase activity was found either. These data produced a variable fermentation coefficient and a unique sourdough metabolite composition.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Xue Zhang ◽  
Shuai Zhang ◽  
Bijun Xie ◽  
Zhida Sun

This study aimed to evaluate the influence of lactic acid bacteria fermentation on the physicochemical properties and antioxidant activity of chickpea yam milk. Four groups of chickpea milk were prepared through fermentation with lactic acid bacteria for quality and functionality improvement. Results indicate that the polysaccharide content of four samples declines during the fermentation process, and their infrared spectrums are similar with a slight difference in the transmittances of some characteristic bands. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) profiles of four samples with 24 h fermentation showed a band disappearance in the range of 94.3 KDa and generation of many small-molecule peptides, revealing the protein degradation during fermentation. The moderate enzymatic hydrolysis had no adverse effect on the texture and color of the samples. A substantial increase in DPPH, ABTS radical scavenging rates, and FRAP value was observed after 12 h fermentation, especially the CPBY sample. The present results indicate that lactic acid bacteria fermentation can be used to improve the physicochemical properties of samples and enhance their antioxidant activity.


2011 ◽  
Vol 74 (5) ◽  
pp. 826-829 ◽  
Author(s):  
A. TOLEDANO ◽  
R. JORDANO ◽  
C. LÓPEZ ◽  
L. M. MEDINA

During the processing of dry-cured meat products, sarcoplasmic and myofibrillar proteins undergo proteolysis, which has a marked effect on product flavor. Microbial proteolytic activity is due to the action of mostly lactic acid bacteria (LAB) and to a lesser extent micrococci. The proteolytic capacity of molds in various meat products is of interest to meat processors in the Mediterranean area. Eleven LAB and mold strains from different commercial origins were tested for proteolytic activity against pork myosin, with a view to possible use of these strains as starter cultures for Iberian dry-cured ham. Proteolytic activity was tested by sodium dodecyl sulfate–polyacrylamide gel electrophoresis. The LAB strains with the highest proteolytic activity were Lactobacillus plantarum (L115), Pediococcus pentosaceus (Saga P TM), and Lactobacillus acidophilus (FARGO 606 TM). The best fungal candidate was Penicillium nalgiovense LEM 50I followed by Penicillium digitatum, Debaryomyces hansenii, and Penicillium chrysogenum.


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