scholarly journals Diversity and Antimicrobial Properties of Lactic Acid Bacteria Isolated from Rhizosphere of Olive Trees and Desert Truffles of Tunisia

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Imene Fhoula ◽  
Afef Najjari ◽  
Yousra Turki ◽  
Sana Jaballah ◽  
Abdelatif Boudabous ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Pathogenic Bacteria ◽  
Antimicrobial Properties ◽  
Intergenic Spacer ◽  
Penicillium Expansum ◽  
Rrna Gene ◽  
Food Borne ◽  
Olive Trees ◽  
Desert Truffles

A total of 119 lactic acid bacteria (LAB) were isolated, by culture-dependant method, from rhizosphere samples of olive trees and desert truffles and evaluated for different biotechnological properties. Using the variability of the intergenic spacer 16S-23S and 16S rRNA gene sequences, the isolates were identified as the generaLactococcus, Pediococcus, Lactobacillus, Weissella,andEnterococcus. All the strains showed proteolytic activity with variable rates 42% were EPS producers, while only 10% showed the ability to grow in 9% NaCl. In addition, a low rate of antibiotic resistance was detected among rhizospheric enterococci. Furthermore, a strong antibacterial activity against plant and/or pathogenic bacteria ofStenotrophomonas maltophilia, Pantoea agglomerans, Pseudomonas savastanoi, the food-borneStaphylococcus aureus,andListeria monocytogeneswas recorded. Antifungal activity evaluation showed thatBotrytis cinereawas the most inhibited fungus followed byPenicillium expansum, Verticillium dahliae,andAspergillus niger. Most of the active strains belonged to the generaEnterococcusandWeissella. This study led to suggest that environmental-derived LAB strains could be selected for technological application to control pathogenic bacteria and to protect food safety from postharvest deleterious microbiota.

scholarly journals Isolation and Characterization of Lactic Acid Bacteria and Yeasts from Typical Bulgarian Sourdoughs

2021 ◽  
Vol 9 (7) ◽  
pp. 1346
Author(s):  
Mariana Petkova ◽  
Petya Stefanova ◽  
Velitchka Gotcheva ◽  
Angel Angelov
Keyword(s):  
Lactic Acid ◽  
Sequence Analysis ◽  
Lactic Acid Bacteria ◽  
Antimicrobial Properties ◽  
Matter Content ◽  
Starter Cultures ◽  
Rrna Gene ◽  
Dry Matter Content ◽  
Isolation And Characterization ◽  
Selection Of

Traditional sourdoughs in Bulgaria were almost extinct during the centralized food production system. However, a rapidly developing trend of sourdough revival in the country is setting the demand for increased production and use of commercial starter cultures. The selection of strains for such cultures is based on geographical specificity and beneficial technological properties. In this connection, the aim of this study was to isolate, identify and characterize lactic acid bacteria (LAB) and yeasts from typical Bulgarian sourdoughs for the selection of strains for commercial sourdough starter cultures. Twelve samples of typical Bulgarian sourdoughs were collected from different geographical locations. All samples were analyzed for pH, total titratable acidity and dry matter content. Enumeration of LAB and yeast was also carried out. Molecular identification by 16S rDNA sequence analysis was performed for 167 LAB isolates, and 106 yeast strains were identified by ITS1-5.8S-ITS2 rRNA gene partial sequence analysis. The LAB strains were characterized according to their amylolytic and proteolytic activity and acidification capacity, and 11 strains were selected for further testing of their antimicrobial properties. The strains with the most pronounced antibacterial and antifungal activity are listed as recommended candidates for the development of starter cultures for sourdoughs or other food products.

scholarly journals Prevention of Intramammary Infections by Prepartum External Application of a Teat Dip Containing Lactic Acid Bacteria with Antimicrobial Properties in Dairy Heifers

Pathogens ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 288
Author(s):  
Jan-Hendrik Paduch ◽  
Johanna Lücking ◽  
Elisabeth Mansion-de Vries ◽  
Claudia Zinke ◽  
Nicole Wente ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Pathogenic Bacteria ◽  
Aqueous Suspension ◽  
Antimicrobial Properties ◽  
Clinical Mastitis ◽  
External Application ◽  
Intramammary Infections ◽  
Dairy Heifers ◽  
Major Pathogens

The aim of the current study was to investigate the effects of the prepartum external treatment of teats with a combination of four lactic acid bacteria strains viz. Lactobacillus (Lb.) rhamnosus ATCC 7469, Lactococcus lactis subsp. lactis ATCC 11454, Lb. paracasei 78/37 (DSM 26911), and Lb. plantarum 118/37 (DSM 26912) on the postcalving udder health of dairy heifers. The study used a split-udder design. Two weeks before the expected calving date, one of two contralateral teats of a teat pair was dipped with an aqueous suspension of lactic acid bacteria (final bacterial counts 8.40–8.47 log10-transformed CFU/mL) once in a week until calving; the other teat of the pair was not treated. After calving, quarter foremilk samples were taken and investigated cyto-microbiologically. In total, 629 teat pairs of 319 heifers were included. There was an association between the treatment and intramammary infections caused by the major udder-pathogenic bacteria Staphylococcus aureus, Streptococcus dysgalactiae, and enterococci, as well as clinical mastitis in the first 100 days after calving. The present study indicates that intramammary infections with major pathogens and clinical mastitis may be prevented by regular prepartum external application of lactic acid bacteria in dairy heifers.

scholarly journals Bacteriocins of lactic acid bacteria and their application on food as biopreservatives. (II)

2017 ◽  
Vol 54 (1) ◽  
pp. 69
Author(s):  
J. METAXOPOULOS (Ι. ΜΕΤΑΞΟΠΟΥΛΟΣ) ◽  
M. MATARAGAS (M. ΜΑΤΑΡΑΓΚΑΣ) ◽  
E. H. DROSINOS (Ε.Χ. ΔΡΟΣΙΝΟΣ)
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Peroxide ◽  
Molecular Weight ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Pathogenic Bacteria ◽  
Antimicrobial Properties ◽  
Small Molecular Weight ◽  
Inhibitory Spectrum ◽  
Protective Cultures

Lactic acid bacteria produce a variety of small molecular weight compounds, which have antimicrobial properties. Such substances are: organic acids, alcohols, carbon dioxide, diacetyl, hydrogen peroxide and bacteriocins. Many of these compounds have a wide inhibitory spectrum but the bacteriocins are able to inhibit species, namely, related with the bacteriocin-producing strain. In the last years bacteriocins have gained a lot of concern because some of them are able to inhibit the growth of pathogenic bacteria, like Listeria monocytogenes. The term "biopreservation" refers to the extension of storage life, as well as to the enhancement of the food safety, using the bacteriocin-producing lactic acid strains or their metabolic antibacterial products. In this review will be reported bacteriocins, which are produced by the lactic acid bacteria and will be discussed the potential application of the bacteriocinogenic strains or their bacteriocins on the foods, as protective cultures or as protective compounds, respectively.

scholarly journals Evaluation of the probiotic and postbiotic potential of lactic acid bacteria from artisanal dairy products against pathogens

2021 ◽  
Vol 15 (01) ◽  
pp. 102-112
Author(s):  
Nazar Hussain ◽  
Muhammad Tariq ◽  
Per Erik Joakim Saris ◽  
Arsalan Zaidi
Keyword(s):  
Antibacterial Activity ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Pathogenic Bacteria ◽  
16S Rrna Gene Sequencing ◽  
Lactobacillus Delbrueckii ◽  
Human Consumption ◽  
Rrna Gene ◽  
Microdilution Method

Introduction: Probiotic and postbiotic potential of thirty-two strains of lactic acid bacteria (LAB), obtained earlier from artisanal dairy sources in Pakistan, have been investigated against major multi-drug resistant (MDR) and food borne pathogenic bacteria. Methodology: LAB strains were identified by 16S rRNA gene sequencing and their antibacterial activity was assessed by the microdilution method. Four LAB isolates, Weissella confusa PL6, Enterococcus faecium PL7, and Lactobacillus delbrueckii PL11 and PL13 were shortlisted. Their ability to degrade lactose and safety for human consumption in terms of hemolysis and antibiotic susceptibility were assessed in vitro. The antibacterial components in the cell-free supernatants (CFSs) of isolate cultures were characterized biochemically by HPLC. Results: Acid neutralization but not protease treatment abolished the antibacterial activity of CFSs. Lactic, acetic and propionic acids were the main acids in the CFSs, and acid production peaked in the stationary phase of growth. The antibacterial activity of the LAB cultures resulted from secretion of organic acids that lowered the pH. The strains exhibited variable ability to degrade lactose and were non-hemolytic and susceptible to the most common antibiotics. Conclusions: These LAB strains are probiotic candidates for further investigation of their postbiotic role in naturally preserving processed foods and for attenuation of lactose intolerance.

scholarly journals Antilisterial Potential of Lactic Acid Bacteria in Eliminating Listeria monocytogenes in Host and Ready-to-Eat Food Application

2021 ◽  
Vol 12 (1) ◽  
pp. 234-257
Author(s):  
Phui-Chyng Yap ◽  
Nor-Aziyah MatRahim ◽  
Sazaly AbuBakar ◽  
Hai Yen Lee
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Vaccine Development ◽  
Antimicrobial Properties ◽  
Listeriolysin O ◽  
Gene Coding ◽  
Food Borne ◽  
Eagle Effect ◽  
Contaminated Food

Listeriosis is a severe food borne disease with a mortality rate of up to 30% caused by pathogenic Listeria monocytogenes via the production of several virulence factors including listeriolysin O (LLO), transcriptional activator (PrfA), actin (Act), internalin (Int), etc. It is a foodborne disease predominantly causing infections through consumption of contaminated food and is often associated with ready-to-eat food (RTE) and dairy products. Common medication for listeriosis such as antibiotics might cause an eagle effect and antibiotic resistance if it is overused. Therefore, exploration of the use of lactic acid bacteria (LAB) with probiotic characteristics and multiple antimicrobial properties is increasingly getting attention for their capability to treat listeriosis, vaccine development, and hurdle technologies. The antilisterial gene, a gene coding to produce antimicrobial peptide (AMP), one of the inhibitory substances found in LAB, is one of the potential key factors in listeriosis treatment, coupled with the vast array of functions and strategies; this review summarizes the various strategies by LAB against L. monocytogenes and the prospect in development of a ‘generally regarded as safe’ LAB for treatment of listeriosis.

scholarly journals Prevalence and Antimicrobial Properties of Lactic Acid Bacteria in Nigerian Women During the Menstrual Cycle

2019 ◽  
Vol 68 (2) ◽  
pp. 203-209 ◽  
Author(s):  
FOLASHADE GRACE ADEOSHUN ◽  
WERNER RUPPITSCH ◽  
FRANZ ALLERBERGER ◽  
FUNMILOLA ABIDEMI AYENI
Keyword(s):  
Lactic Acid ◽  
Menstrual Cycle ◽  
Lactic Acid Bacteria ◽  
Antimicrobial Properties ◽  
Lactobacillus Brevis ◽  
Acetic Acid Bacteria ◽  
Antimicrobial Activities ◽  
Protective Role ◽  
Rrna Gene ◽  
Nigerian Women

The composition of vagina lactic acid bacteria (LAB) differs within the different ethnic group. This study is aimed at determining the prevalence of LAB with their antimicrobial properties in Nigerian women’s vagina during different stages of the menstrual cycle. Microorganisms were isolated from vaginal swabs of ten Nigerian women during different stages of the menstrual cycle and identified by partial sequencing of the 16S rRNA gene. The antimicrobial properties of the LAB were tested against the multidrug-resistant uropathogens. The prevalence of LAB was higher during ovulation period while during menstruation period, it declined. Twenty-five LAB isolates were identified as three species, namely: Lactobacillus plantarum (15), Lactobacillus fermentum (9), Lactobacillus brevis (1) and one acetic acid bacteria – Acetobacter pasteurianus. The LAB had antimicrobial activities against the three uropathogens with zones of inhibition from 8 to 22 mm. The presence of LAB inhibits the growth of Staphylococcus sp. GF01 also in the co-culture. High LAB counts were found during ovulation period with L.plantarum as a dominant species while during menstruation, there was a decrease in the LAB counts. The isolated LAB has antimicrobial properties against the urogenital pathogens tested thus exhibiting their potential protective role against uropathogens.

scholarly journals Identification and probiotic properties of lactobacilli isolated from two different fermented beverages

2019 ◽  
Vol 69 (13) ◽  
pp. 1557-1565 ◽  
Author(s):  
Iulia-Roxana Angelescu ◽  
Medana Zamfir ◽  
Mihaela-Marilena Stancu ◽  
Silvia-Simona Grosu-Tudor
Keyword(s):  
Antibacterial Activity ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Pathogenic Bacteria ◽  
Scientific Information ◽  
Lactobacillus Delbrueckii ◽  
Rrna Gene ◽  
Probiotic Properties ◽  
Fermented Beverages ◽  
Water Kefir

Abstract Purpose Scientific information regarding the microbial content and functional aspects of fermented beverages traditionally produced in certain parts of Europe are scarce. However, such products are believed to have some health benefits and might contain functional bacterial strains, such as probiotics. The aim of the study was to identify such lactic acid bacteria strains isolated from water kefir and, for the first time, from braga, a Romanian fermented beverage made of cereals. Methods Lactic acid bacteria (LAB) were identified to species level based on (GTG)5-PCR fingerprinting and 16S rRNA gene sequencing. Selected strains were screened for their antibacterial activity and probiotic potential. Results Eight isolates belonging to seven Lactobacillus species were recovered from the two drinks. The identification of LAB involved in the fermentation of braga (Lactobacillus plantarum, Lactobacillus fermentum, and Lactobacillus delbrueckii) is firstly reported here. Five of the Lactobacillus isolates showed antibacterial activity against pathogenic bacteria, including Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Salmonella enterica. Moreover, most of them showed a good resistance to pH 2.5 and some survived at high concentrations of bile salts (up to 2%). Two L. plantarum isolates were able to inhibit all the indicator strains, and showed the best viability (about 70%) after a sequential treatment simulating the passage through the gastrointestinal tract. Conclusion Based on the results, the most promising candidates for designing new probiotic products are: L. plantarum BR9 from braga and L. plantarum CR1 from water kefir.

Sign in / Sign up

Export Citation Format

Share Document