scholarly journals Anti-Toxigenic Effect of Lactic Acid Bacteria Against Aspergillus spp Isolated from Wheat Grains

2020 ◽  
Vol 14 (1) ◽  
pp. 252-259
Author(s):  
Mohamed T. Fouad ◽  
Tarek A. El-Desouky

Introduction: Many fungi infect the wheat grains. Under field and or storage conditions from temperature and humidity, some fungi can produce aflatoxins (AFs), which may cause acute or chronic diseases. Therefore, there is a necessary and urgent need to find an effective and safe way to reduce or remove AFs. Objective: The objective of this study was the evaluation of Lactobacillus rhamnosus, Lactobacillus gasseri, and Lactobacillus plantarum for their ability to reduce and or remove AFs produced by Aspergillus flavus and Aspergillus parasiticus, which were isolated from wheat grains, as well as control of AFs produced on affected wheat grain by A.parasiticus spores only. Methods: LAB, isolated from some local dairy products, were cultured in MRS for the evaluation of their ability to remove AFs, produced by A. flavus and A. parasiticus on (YES) media, in addition to the treatment of wheat grains by LAB cells to prevent AFs produced by A. parasiticus. Results: The L. rhamnosus strain gave the highest reduction rates of AFs produced by A. parasiticus that were 62.6, 44.4, 43.3, and 52.2% for AFG1, AFB1, AFG2, and AFB2, respectively. While in the case of A. flavus, the reduction was 50.4, 42.7, 40.6, and 36.8% in the same order of toxins. When applied, these strains with wheat grains were affected by A. parasiticus, the inhibition rates of AFs were ranged between 61.4 and 75.8% with L. rhamnosus strain and 43.7 to 52.1% with L. gasseri, while L. plantarum strain ranged from 55.5 to 66.9%. Conclusion: According to this study, L. rhamnosus is considered one of the best strains in this field. Therefore, the present study suggests applied use of LAB as a treatment to prevent AFs production in wheat grains.

Author(s):  
J Mättö ◽  
R Fondén ◽  
M Saarela ◽  
Arla Foods Ics ◽  
T Mattila-Sandholm

2021 ◽  
Vol 26 (2) ◽  
pp. 2548-2559
Author(s):  
VIORICA CORBU ◽  
◽  
STEFANA PETRUT ◽  
TATIANA VASSU ◽  
DIANA PELINESCU ◽  
...  

During last decades, there is a growing interest for characterizing new microbial strains isolated from various sources (plants, soil and natural fermentative processes), in order to enhance industrial productivity. The aim of the present study was to assess the profile of cell growth parameters and biomass accumulation of 15 newly isolated yeast and lactic acid bacteria (LAB) strains from Romanian spontaneous fermented dairy products under different environmental stress conditions (chemical and physical). On this purpose, the yeast and LAB strains were characterized and identified using MALDI-TOF MS and selected for their biotechnological potential. Cell growth was evaluated in presence of extreme pH values, temperatures and different NaCl concentrations. All strains included in this study grew well under their optimal conditions; some of them preferred extreme parameters: acid / very alkaline pH, high temperatures or NaCl concentration The characterization of microbiota from Romanian spontaneous fermented dairy products might represent a great opportunity for the development of dairy industry using native microorganisms, preserving thus the Romanian biodiversity and cultural heritage.


2014 ◽  
Vol 5 (8) ◽  
pp. 561-579
Author(s):  
S. EL-Ghaish ◽  
Azza EL-Baz ◽  
N. Hwanhlem ◽  
M. Zommara ◽  
Eman Ayad ◽  
...  

2020 ◽  
Vol 8 (2) ◽  
pp. 301
Author(s):  
Fernando Sánchez-Juanes ◽  
Vanessa Teixeira-Martín ◽  
José Manuel González-Buitrago ◽  
Encarna Velázquez ◽  
José David Flores-Félix

Several artisanal cheeses are elaborated in European countries, being commonly curdled with rennets of animal origin. However, in some Spanish regions some cheeses of type “Torta” are elaborated using Cynara cardunculus L. rennets. Two of these cheeses, “Torta del Casar” and “Torta de Trujillo”, are elaborated in Cáceres province with ewe’s raw milk and matured over at least 60 days without starters. In this work, we identified the lactic acid bacteria present in these cheeses using MALDI-TOF MS and pheS gene analyses, which showed they belong to the species Lactobacillus curvatus, Lactobacillus diolivorans, Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus rhamnosus, Lactococcus lactis and Leuconostoc mesenteroides. The pheS gene analysis also allowed the identification of the subspecies La. plantarum subsp. plantarum, La. paracasei subsp. paracasei and Le. mesenteroides subsp. jonggajibkimchii. Low similarity values were found in this gene for some currently accepted subspecies of Lc. lactis and for the two subspecies of La. plantarum, and values near to 100% for the subspecies of Le. mesenteroides and La. paracasei. These results, which were confirmed by the calculated ANIb and dDDH values of their whole genomes, showed the need to revise the taxonomic status of these species and their subspecies.


2019 ◽  
Vol 7 (10) ◽  
pp. 407 ◽  
Author(s):  
Hadar Kimelman ◽  
Moshe Shemesh

Live probiotic bacteria obtained with food are thought to have beneficial effects on a mammalian host, including their ability to reduce intestinal colonization by pathogens. To ensure the beneficial effects, the probiotic cells must survive processing and storage of food, its passage through the upper gastrointestinal tract (GIT), and subsequent chemical ingestion processes until they reach their target organ. However, there is considerable loss of viability of the probiotic bacteria during the drying process, in the acidic conditions of the stomach, and in the high bile concentration in the small intestine. Bacillus subtilis, a spore-forming probiotic bacterium, can effectively maintain a favorable balance of microflora in the GIT. B. subtilis produces a protective extracellular matrix (ECM), which is shared with other probiotic bacteria; thus, it was suggested that this ECM could potentially protect an entire community of probiotic cells against unfavorable environmental conditions. Consequently, a biofilm-based bio-coating system was developed that would enable a mutual growth of B. subtilis with different lactic acid bacteria (LAB) through increasing the ECM production. Results of the study demonstrate a significant increase in the survivability of the bio-coated LAB cells during the desiccation process and passage through the acidic environment. Thus, it provides evidence about the ability of B. subtilis in rescuing the desiccation-sensitive LAB, for instance, Lactobacillus rhamnosus, from complete eradication. Furthermore, this study demonstrates the antagonistic potential of the mutual probiotic system against pathogenic bacteria such as Staphylococcus aureus. The data show that the cells of B. subtilis possess robust anti-biofilm activity against S. aureus through activating the antimicrobial lipopeptide production pathway.


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