scholarly journals In Vitro Antagonistic Effect of Lactic Acid Bacteria Isolated from Fermented Beverage and Finfish on Pathogenic and Foodborne Pathogenic Microorganism in Ethiopia

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Fitsum Dejene ◽  
Belayneh Regasa Dadi ◽  
Dagimawie Tadesse
Keyword(s):  
Antimicrobial Activity ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Proteolytic Enzymes ◽  
Diffusion Method ◽  
Fermented Foods ◽  
Cell Free Supernatant ◽  
Wide Range ◽  
Fermented Beverage

Background. Lactic acid bacteria from fermented foods and fish can antagonistically inhibit the growth of foodborne pathogenic organism in fermented food and they stimulate the immune response to protect the fish from certain kinds of infections. The aim of this study was to evaluate the in vitro antagonistic activities of lactic acid bacteria isolated from fermented beverage (Borde) and finfish on foodborne pathogenic microorganisms. Methods. Laboratory-based experimental study was conducted from May 1 to Sep 1, 2020. Total sample numbers were 60 samples of fermented beverage (Borde) and 20 of finfish which were collected from different households and Chamo Lake (Arba Minch, Ethiopia). Each sample was firstly homogenized and serial dilution was prepared and spread on MRS agar plates in order to isolate pure culture. Different biochemical tests were performed to identify isolated bacteria. Then, cell-free supernatant (CFS) was prepared from MRS culture and used in an antimicrobial assay that was performed by agar diffusion method. The effects of pH, temperature, and enzymes on antimicrobial activity were evaluated in the same test. Simultaneously, the effects of lactic acid bacteria on aflatoxin production and on the permeability of the membrane were also evaluated. Data were analyzed using one-way ANOVA and Tukey post hoc analysis was performed by SPSS 25 statistical software. Result. A total of 40 lactic acid bacteria were isolated; among them, 4 lactic acid bacteria, belonging to the genera Enterococcus, Leuconostoc, and Weisellia from fermented beverage and Pediococcus from fish, were screened for antimicrobial activity. The cell-free supernatant of those four isolates exhibited a significant ( p < 0.05 ) antibacterial effect against tested pathogens and foodborne pathogenic bacteria. In addition, CFS showed antifungal and antiaflatoxigenic activities. The antimicrobial compounds synthesized by these isolates were sensitive to some proteolytic enzymes, and they were proved to be stable at high temperatures. It maintained/retained antimicrobial activity in a wide range of pH 2.0–10. Enterococcal CFS exhibited antibacterial activity against S. aureus on membrane permeability, as confirmed by the increase in absorbance value between 0.075 and 0.24 at OD280-nm and between 0.68 and 1.2 at OD260-nm. Conclusion. Cell-free supernatant produced by isolated lactic acid bacteria showed antimicrobial activity against a wide range of Gram-positive and Gram-negative foodborne bacteria, suggesting its potential application as a natural antimicrobial agent in tackling the rising drug resistance against foodborne pathogens.

scholarly journals Potential Screening of Bacteriocinogenic-Lactic Acid Bacteria from Mangrove Sediment of Logending Beach for Fisheries Product Preservation

2021 ◽  
Vol 6 (1) ◽  
pp. 61927
Author(s):  
Dyah Fitri Kusharyati ◽  
Taruna Dwi Satwika ◽  
Afifah Mariana ◽  
Anwar Rovik
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Pathogenic Bacteria ◽  
Proteolytic Enzymes ◽  
Shigella Flexneri ◽  
Salmonella Typhi ◽  
Mangrove Sediment ◽  
In Vitro Test ◽  
Cell Free Supernatant

The meat and fisheries products have high nutritional content which is highly ideal for bacterial growth. Lactic Acid Bacteria (LAB) have several potential advantages as a bio-preservative agent in the food industry because they produce antimicrobial substances against pathogenic bacteria e.g. bacteriocin. Our previous study has succeeded in isolating and characterizing LAB from the mangrove sediments of Logending Beach, Kebumen. This present study aimed to determine the activity of bacteriocinogenic-LAB against food-borne pathogens and their potential for fisheries product preservation. The study consisted of five serial stages, as follows: screening of LAB isolates, cell-free supernatant production and its inhibition activity, extraction of partially purified bacteriocin, bacteriocin confirmation against proteolytic enzymes, and in-vitro test of partially-purified bacteriocin against Listeria monocytogenes, Shigella flexneri, and Salmonella typhi. A total of 25 out of 99 isolates were able to grow on MRSA+1% CaCO3 medium. Initial screening showed that the cell-free supernatant of 14 LAB isolates was able to inhibit the growth of S. thypi, S. flexneri, and L. monocytogenes. There was an increased inhibitory activity of partially purified bacteriocin when compared with the cell-free supernatant which was statistically different (p<0.01). It indicated that the purification was successfully performed. Bacteriocin expressed a lower inhibition against S. typhi than L. monocytogenes and S. flexneri. The ANOVA test showed that each indicator pathogenic-bacterium expresses a very significant sensitivity to the partially purified bacteriocin.

scholarly journals Proteolysis by Sourdough Lactic Acid Bacteria: Effects on Wheat Flour Protein Fractions and Gliadin Peptides Involved in Human Cereal Intolerance

2002 ◽  
Vol 68 (2) ◽  
pp. 623-633 ◽  
Author(s):  
Raffaella Di Cagno ◽  
Maria De Angelis ◽  
Paola Lavermicocca ◽  
Massimo De Vincenzi ◽  
Claudio Giovannini ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Protein Extraction ◽  
Proteolytic Enzymes ◽  
Lactobacillus Brevis ◽  
Enzyme Preparations ◽  
Wide Range ◽  
Gliadin Peptides ◽  
Hydrolysis Of

ABSTRACT Sourdough lactic acid bacteria were preliminarily screened for proteolytic activity by using a digest of albumin and globulin polypeptides as a substrate. Based on their hydrolysis profile patterns, Lactobacillus alimentarius 15M, Lactobacillus brevis 14G, Lactobacillus sanfranciscensis 7A, and Lactobacillus hilgardii 51B were selected and used in sourdough fermentation. A fractionated method of protein extraction and subsequent two-dimensional electrophoresis were used to estimate proteolysis in sourdoughs. Compared to a chemically acidified (pH 4.4) dough, 37 to 42 polypeptides, distributed over a wide range of pIs and molecular masses, were hydrolyzed by L. alimentarius 15M, L. brevis 14G, and L. sanfranciscensis 7A. Albumin, globulin, and gliadin fractions were hydrolyzed, while glutenins were not degraded. The concentrations of free amino acids, especially proline and glutamic and aspartic acids, also increased in sourdoughs. Compared to the chemically acidified dough, proteolysis by lactobacilli positively influenced the softening of the dough during fermentation, as determined by rheological analyses. Enzyme preparations of the selected lactobacilli which contained proteinase or peptidase enzymes showed hydrolysis of the 31-43 fragment of A-gliadin, a toxic peptide for celiac patients. A toxic peptic-tryptic (PT) digest of gliadins was used for in vitro agglutination tests on K 562 (S) subclone cells of human myelagenous leukemia origin. The lowest concentration of PT digest that agglutinated 100% of the total cells was 0.218 g/liter. Hydrolysis of the PT digest by proteolytic enzymes of L. alimentarius 15M and L. brevis 14G completely prevented agglutination of the K 562 (S) cells by the PT digest at a concentration of 0.875 g/liter. Considerable inhibitory effects by other strains and at higher concentrations of the PT digest were also found. The mixture of peptides produced by enzyme preparations of selected lactobacilli showed a decreased agglutination of K 562 (S) cells with respect to the whole 31-43 fragment of A-gliadin.

Cell-free supernatants produced by lactic acid bacteria reduce Salmonella population in vitro

Microbiology ◽  
2021 ◽  
Vol 167 (11) ◽  
Author(s):  
Alberto Gonçalves Evangelista ◽  
Jessica Audrey Feijó Corrêa ◽  
João Vitor Garcia dos Santos ◽  
Eduardo Henrique Custódio Matté ◽  
Mônica Moura Milek ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Lactic Acid ◽  
Antimicrobial Resistance ◽  
Lactic Acid Bacteria ◽  
Type Species ◽  
Feed Additives ◽  
Poultry Feed ◽  
Content Type ◽  
Link Type

The genus Salmonella is closely associated with foodborne outbreaks and animal diseases, and reports of antimicrobial resistance in Salmonella species are frequent. Several alternatives have been developed to control this pathogen, such as cell-free supernatants (CFS). Our objective here was to evaluate the use of lactic acid bacteria (LAB) CFS against Salmonella in vitro. Seventeen strains of LAB were used to produce CFS, and their antimicrobial activity was screened towards six strains of Salmonella . In addition, CFS were also pH-neutralized and/or boiled. Those with the best results were lyophilized. MICs of lyophilized CFS were 11.25–22.5 g l–1. Freeze-dried CFS were also used to supplement swine and poultry feed (11.25 g kg–1) and in vitro simulated digestion of both species was performed, with Salmonella contamination of 5×106 and 2×105 c.f.u. g−1 of swine and poultry feed, respectively. In the antimicrobial screening, all acidic CFS were able to inhibit the growth of Salmonella . After pH neutralization, Lactobacillus acidophilus Llorente, Limosilactobacillus fermentum CCT 1629, Lactiplantibacillus plantarum PUCPR44, Limosilactobacillus reuteri BioGaia, Lacticaseibacillus rhamnosus ATCC 7469 and Pediococcus pentosaceus UM116 CFS were the only strains that partially maintained their antimicrobial activity and, therefore, were chosen for lyophilization. In the simulated swine digestion, Salmonella counts were reduced ≥1.78 log c.f.u. g–1 in the digesta containing either of the CFS. In the chicken simulation, a significant reduction was obtained with all CFS used (average reduction of 0.59±0.01 log c.f.u. ml–1). In general, the lyophilized CFS of L. fermentum CCT 1629, L. rhamnosus ATCC 7469 and L. acidophilus Llorente presented better antimicrobial activity. In conclusion, CFS show potential as feed additives to control Salmonella in animal production and may be an alternative to the use of antibiotics, minimizing problems related to antimicrobial resistance.

scholarly journals Isolation, Identification, and Evaluation of New Lactic Acid Bacteria Strains with Both Cellular Antioxidant and Bile Salt Hydrolase Activities In Vitro

2016 ◽  
Vol 79 (11) ◽  
pp. 1919-1928 ◽  
Author(s):  
SHUANG XU ◽  
TAIGANG LIU ◽  
CHIRAZ AKOREDE IBINKE RADJI ◽  
JING YANG ◽  
LANMING CHEN
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Bile Salt ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Genomic Diversity ◽  
Bile Salt Hydrolase ◽  
Fermented Foods ◽  
Intact Cells

ABSTRACT In this study, we analyzed Chinese traditional fermented food to isolate and identify new lactic acid bacteria (LAB) strains with novel functional properties and to evaluate their cellular antioxidant and bile salt hydrolase (BSH) activities in vitro. A sequential screening strategy was developed to efficiently isolate and obtain 261 LAB strains tolerant of bile salt, acid, and H2O2 from nine Chinese traditional fermented foods. Among these strains, 70 were identified as having 2,2-diphenyl-1-picrylhydrazyl radical scavenging and/or BSH activity. These strains belonged to eight species: Enterococcus faecium (33% of the strains), Lactobacillus plantarum (26%), Leuconostoc mesenteroides (14%), Pediococcus pentosaceus (6%), Enterococcus durans (9%), Lactobacillus brevis (9%), Pediococcus ethanolidurans (3%), and Lactobacillus casei (1%). The pulsed-field gel electrophoresis genome fingerprinting profiles of these strains revealed 38 distinct pulsotypes, indicating a high level of genomic diversity among the tested strains. Twenty strains were further evaluated for hydroxyl radical scavenging activity, reducing power, and ferrous ion chelating activity exerted by both viable intact cells and/or intracellular cell-free extracts. Some strains, such as L. plantarum D28 and E. faecium B28, had high levels of both cellular antioxidant and BSH activities in vitro. These strains are promising probiotic components for health-promoting functional foods.

scholarly journals Screening of Indigenous Oxalate Degrading Lactic Acid Bacteria from Human Faeces and South Indian Fermented Foods: Assessment of Probiotic Potential

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Sivasamy Gomathi ◽  
Ponnusamy Sasikumar ◽  
Kolandaswamy Anbazhagan ◽  
Sundaresan Sasikumar ◽  
Murugan Kavitha ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactobacillus Fermentum ◽  
Fermented Foods ◽  
Lactobacillus Salivarius ◽  
Human Faeces ◽  
South Indian ◽  
Rdna Sequencing ◽  
Acid And Bile Tolerance

Lactic acid bacteria (LAB) have the potential to degrade intestinal oxalate and this is increasingly being studied as a promising probiotic solution to manage kidney stone disease. In this study, oxalate degrading LAB were isolated from human faeces and south Indian fermented foods, subsequently assessed for potential probiotic propertyin vitroandin vivo. Based on preliminary characteristics, 251 out of 673 bacterial isolates were identified as LAB. A total of 17 strains were found to degrade oxalate significantly between 40.38% and 62.90% and were subjected to acid and bile tolerance test. Among them, nine strains exhibited considerable tolerance up to pH 3.0 and at 0.3% bile. These were identified asLactobacillus fermentumandLactobacillus salivariususing 16S rDNA sequencing. Three strains,Lactobacillus fermentumTY5,Lactobacillus fermentumAB1, andLactobacillus salivariusAB11, exhibited good adhesion to HT-29 cells and strong antimicrobial activity. They also conferred resistance to kanamycin, rifampicin, and ampicillin, but were sensitive to chloramphenicol and erythromycin. The faecal recovery rate of these strains was observed as 15.16% (TY5), 6.71% (AB1), and 9.3% (AB11) which indicates the colonization ability. In conclusion, three efficient oxalate degrading LAB were identified and their safety assessments suggest that they may serve as good probiotic candidates for preventing hyperoxaluria.

scholarly journals Inhibitory activity of crude bacteriocin produced by lactic acid bacteria isolated from dadih against Listeria monocytogenes

2020 ◽  
Vol 21 (4) ◽  
Author(s):  
Usman Pato ◽  
YUSMARINI YUSUF ◽  
SHANTI FITRIANI ◽  
NIA NAIDYA JONNADI ◽  
MIMI SRI WAHYUNI ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Inhibition Zone ◽  
Diffusion Method ◽  
Antimicrobial Compounds ◽  
Disk Diffusion Method ◽  
Food Borne ◽  
Paper Disk ◽  
Natural Preservatives

The use of natural preservatives called bacteriocin derived from lactic acid bacteria (LAB) is one way of preventing food from being contaminated by pathogenic microorganisms such as L. monocytogenes (LM). The aims of this study were to evaluate the ability of LAB isolated from dadih to inhibit the growth of LM and to obtain the antimicrobial components that play a role in inhibiting the growth of LM. The antimicrobial activity of the supernatant obtained from 12 strains of dadih LAB was determined using the paper disk diffusion method. The results showed that the supernatant from the 12 LAB strains was able to inhibit the growth of LM with various inhibition zones. However, out of the 12 LABs, only 9 strains were found to have an inhibition zone of more than 3.5 mm.  The antimicrobial compounds of 9 strains were tested and it was found that the antimicrobial compounds of strains R-8, R-14 and R-49 were derived from lactic acid. In addition, 6 strains namely R-43, R-32, R-19, R-55, R-45 and R-41 were derived from bacteriocin based on their sensitivity to pH, heat and enzyme treatments. Crude bacteriocin derived from 6 LAB strains inhibited the growth of LM, and the highest antimicrobial activity was obtained in Streptococcus faecalis subsp. liquefaciens R-55 with an average inhibition zone of 13.87 mm. Bacteriocin produced by strain R-55 can be used as natural preservatives for the prevention of food-borne disease caused by LM.

scholarly journals Bacteriocinogenic lactic acid bacteria in the traditional cereal-based beverage Boza: a genomic and functional approach

2021 ◽  
Author(s):  
Luciano Lopes Queiroz ◽  
Christian Hoffmann ◽  
Gustavo Augusto Lacorte ◽  
Bernadette Dora Gombossy de Melo Franco ◽  
Svetoslav Dimitrov Todorov
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Proteolytic Enzymes ◽  
Food Product ◽  
Balkan Peninsula ◽  
Microbial Interactions ◽  
Fermented Foods ◽  
Pediococcus Pentosaceus ◽  
Bacteriophage Infection ◽  
A Cell

Boza is a traditional low-alcohol fermented beverage from the Balkan Peninsula, frequently explored as a functional food product. The product is rich in Lactic Acid Bacteria (LAB) and some of them can produce bacteriocins. In this study, a sample of Boza from Belogratchik, Bulgaria, was analyzed for the presence of bacteriocinogenic LAB, and after analyses by RAPD-PCR, three representative isolates were characterized by genomic analyses, using whole genome sequencing. Isolates identified as Pediococcus pentosaceus ST75BZ and Pediococcus pentosaceus ST87BZ contained operons encoding for bacteriocins pediocin PA-1 and penocin A, while isolate identified as P. acidilactici ST31BZ contained only the operon for pediocin PA-1 and a CRISPR/Cas system for protection against bacteriophage infection. The antimicrobial activity of bacteriocins produced by the three isolates was inhibited by treatment of the cell-free supernatants with proteolytic enzymes. The produced bacteriocins inhibited the growth of Listeria monocytogenes, Enterococcus spp. and some Lactobacillus spp., among other tested species. The levels of bacteriocin production varied from 3200 AU/ml to 12800 AU/ml recorded against L. monocytogenes 104, 637 and 711, measured at 24 h of incubation at 37oC. All bacteriocins remained active after incubation at pH 2.0 to 10.0. The activity mode of the studied bacteriocins was bactericidal, as determined against L. monocytogenes 104, 637 and 711. In addition, bactericidal activity was demonstrated using a cell leakage β-galactosidase assay, indicating a pore formation mechanism as a mode of action. The present study highlights the importance of combining metagenomic analyses and traditional microbiological approaches as way of characterizing microbial interactions in fermented foods.

scholarly journals Fermented Seeds (“Zgougou”) from Aleppo Pine as a Novel Source of Potentially Probiotic Lactic Acid Bacteria

2019 ◽  
Vol 7 (12) ◽  
pp. 709 ◽  
Author(s):  
Jihen Missaoui ◽  
Dalila Saidane ◽  
Ridha Mzoughi ◽  
Fabio Minervini
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Antioxidant Activities ◽  
Fermented Food ◽  
Aleppo Pine ◽  
Fermented Foods ◽  
Probiotic Potential ◽  
Probiotic Lactic Acid Bacteria ◽  
Gastrointestinal Enzymes

Microorganisms inhabiting fermented foods represent the main link between the consumption of this food and human health. Although some fermented food is a reservoir of potentially probiotic microorganisms, several foods are still unexplored. This study aimed at characterizing the probiotic potential of lactic acid bacteria isolated from zgougou, a fermented matrix consisting of a watery mixture of Aleppo pine′s seeds. In vitro methods were used to characterize the safety, survival ability in typical conditions of the gastrointestinal tract, and adherence capacity to surfaces, antimicrobial, and antioxidant activities. Strains belonged to the Lactobacillus plantarum group and Enterococcus faecalis showed no DNase, hemolytic, and gelatinase activities. In addition, their susceptibility to most of the tested antibiotics, satisfied some of the safety prerequisites for their potential use as probiotics. All the strains tolerated low pH, gastrointestinal enzymes, and bile salts. They displayed a good antibacterial activity and antibiofilm formation against 10 reference bacterial pathogens, especially when used as a cell-free supernatant. Furthermore, the lactic acid bacteria (LAB) strains inhibited the growth of Aspergillus flavus and Aspergillus carbonarius. Finally, they had good antioxidant activity, although depending on the strain. Overall, the results of this work highlight that zgougou represents an important reservoir of potentially probiotic LAB. Obviously, future studies should be addressed to confirm the health benefits of the LAB strains.

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