The Configuration of Aspartic Acid in Cell Walls of Lactic Acid Bacteria and Factors Affecting the Racemization of Aspartic Acid*

Background: Ochratoxin A is a nephrotoxin which may occur in wines characterised by higher pH than the average. In the last decades the mechanisms responsible for ochratoxin A reduction by lactic acid bacteria have been investigated and identified as mainly cell walls adsorption and / or enzymatic conversion to ochratoxin-α, a non-toxic metabolite. Since lactic acid bacteria are involved in the malolactic fermentation during the wine-making process, selected starter cultures could be exploited to guarantee safe ochratoxin A level in wines also from contaminated grapes. A lactic acid bacteria strain (Lactobacillus plantarum V22) was previously selected for its ability of both degrading ochratoxin A and carrying out malolactic fermentation at high pH. Objective: This study was aimed at assessing if the selected L. plantarum strain, can reduce ochratoxin A because it can use it as a carbon source. Methods: L. plantarum V22 was grown in the presence of ochratoxin A in two different synthetic substrates, with or without malic acid, monitoring the reduction of ochratoxin A and the presence of ochratoxin α as an indicator for a toxin enzymatic hydrolysis. The presence of residual not hydrolysed ochratoxin A bound to the bacteria cell walls was also evaluated to quantify the ochratoxin A removal due to simple adsorption. Result: A significant reduction of 19.5 ± 2.0% in ochratoxin A concentration was observed only in the presence of malic acid. The quantified fraction of ochratoxin A adsorbed on cell walls was irrelevant and the metabolite ochratoxin α could not be detected. Conclusion: There is a possibility that L. plantarum V22 can degrade ochratoxin A through a not yet identified metabolic pathway.

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Typical Moroccan goat Lactic Acid Bacteria and their assay as starters

Nova Biotechnologica et Chimica ◽

10.36547/nbc.958 ◽

2021 ◽

Author(s):

Linda Zaaraoui ◽

Abdellah Bouksaim ◽

Maha Elhamdani ◽

Aouatif Benali ◽

Mohammed Oukassou ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Research Study ◽

Goat Milk ◽

Lactobacillus Brevis ◽

Raw Milk ◽

Isolation And Identification ◽

Lactobacillus Pentosus ◽

Factors Affecting ◽

Main Factors

The knowledge of lactic acid bacteria of raw milk and the main factors affecting their variability are particularly important issues for the control of cheese processing and the bioconservation of farm raw milk food products. The present research study concerned the isolation and identification of twenty strains of the Lactobacillus genus from goat milk originating from the Oulmes region, using the API 50 CH system. All isolates found represented five species: Lactobacillus plantarum (43.75 %), Lactobacillus brevis (37.75 %), Lactobacillus pentosus (6.25 %), Lactobacillus salivarus (6.25 %), and Lactobacillus acidophilus (6.25 %). According to biochemical activities, the majority of the strains displayed weak acidification and autolysis activities in milk. In contrast, they showed high extracellular proteolytic activity. All isolates produced exopolysaccharides and most of them could metabolize citrate. The absence of hemolytic activity may suggest the use of these isolates as adjunct starters in the food fermentation process.

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Products of Metabolism and Processing of Lactic Acid Bacteria as Functional Ingredients

Food Science and Applied Biotechnology ◽

10.30721/fsab2018.v1.i1.13 ◽

2018 ◽

Vol 1 (1) ◽

pp. 47 ◽

Cited By ~ 1

Author(s):

Antonina Ivanovna Kapustian ◽

Natalia Cherno ◽

Alexei Kovalenko ◽

Kristina Naumenko ◽

Igor Kushnir

Keyword(s):

Amino Acids ◽

Molecular Weight ◽

Lactic Acid ◽

Lactic Acid Bacteria ◽

Organic Acids ◽

Cell Walls ◽

Degradation Products ◽

Lactobacillus Delbrueckii ◽

Low Molecular Weight ◽

Gel Chromatography

Lactic acid bacteria (LAB) and bifidobacteria (BB) are unique substances that have a lot of biological and physiological effects. Structural components of LAB and BB – peptidoglycans, compounds of the muramylpeptide series, teichoic acids – have powerful immunological properties. Metabolites of LAB and BB – organic acids, hydrogen peroxide, bacteriocins, etc. – provide antagonistic activity, have an indirect impact on the immune system, reducing the antigenic load caused by pathogenic microorganisms. The expediency of peptidoglycans degradation of LAB and BB cell walls is substantiated. Low molecular weight products of the degradation can easily be absorbed and enter into biochemical processes, accelerating the expected functional-physiological effect. To obtain low-molecular products of peptidoglycans degradation, a combination of LAB and BB was used. The combination of LAB and BB is the sum of the test cultures of Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. Bulgaricus, Bifidobacterium bifidum, Lactococcus cremoris, Streptococcus termophilus. Destruction of peptidoglycans of bacterial cell walls was carried out using a combination of disintegrating factors. The efficiency of destruction was determined by the accumulation of low molecular weight peptides (with molecular weight up to 1500 Da), amino acids and soluble protein in the disintegrate. It has been established that the highest accumulation of low molecular weight degradation products occurs when using autolysis followed by enzymatic hydrolysis during 180 min with the ratio of the enzyme : substrate 1 : 100. At the same time ≈ 53% of protein substances pass from insoluble to soluble state. The molecular weight of the obtained products is determined by the gel chromatography method. The qualitative and quantitative content of organic acids, amino acids and vitamins of group В in the hydrolysis products composition was investigated. It was shown that the obtained product possesses high biological effect in the experiment on animals.

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Indigenous lactic acid bacteria of various food commodities and factors affecting their growth and survival

Lactic Acid Bacteria ◽

10.1007/978-3-642-61462-0_11 ◽

1996 ◽

pp. 253-267

Author(s):

Friedrich-Karl Lücke

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Growth And Survival ◽

Factors Affecting ◽

Food Commodities

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Nutritional factors affecting the production of two bacteriocins from lactic acid bacteria on whey

International Journal of Food Microbiology ◽

10.1016/s0168-1605(01)00551-7 ◽

2001 ◽

Vol 70 (3) ◽

pp. 267-281 ◽

Cited By ~ 62

Author(s):

Nelson P Guerra ◽

M.Luisa Rua ◽

Lorenzo Pastrana

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Nutritional Factors ◽

Factors Affecting

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Proinflammatory Cytokine and Nitric Oxide Induction in Murine Macrophages by Cell Wall and Cytoplasmic Extracts of Lactic Acid Bacteria

Journal of Food Protection ◽

10.4315/0362-028x-62.12.1435 ◽

1999 ◽

Vol 62 (12) ◽

pp. 1435-1444 ◽

Cited By ~ 76

Author(s):

MARIA VICTORIA TEJADA-SIMON ◽

JAMES J. PESTKA

Keyword(s):

Nitric Oxide ◽

Cell Wall ◽

Lactic Acid ◽

Lactic Acid Bacteria ◽

Cell Walls ◽

Streptococcus Thermophilus ◽

No Production ◽

Peyer’S Patch ◽

Peyer's Patch

Cells from a number of bacterial genera have been shown to possess mitogenic and polyclonal activating properties when cultured with cells of the immune system. Based on previously reported health immune-enhancing effects of fermented dairy products, we tested the potentiating effects of representative lactic acid bacteria and their extracts on leukocyte function. Specifically, the effects of in vitro exposure to heat-killed cells of Bifidobacterium, Lactobacillus acidophilus, L. bulgaricus, L. casei, L. gasseri, L. helveticus, L. reuteri, and Streptococcus thermophilus, their cell walls, and their cytoplasmic extracts on proliferation as well as cytokine and nitric oxide (NO) production were examined in the RAW 264.7 macrophage cell line. A similar strategy was applied to murine cultures composed of peritoneal, spleen, and Peyer's patch cells. Both the cell wall and cytoplasmic fractions of lactic acid bacteria were able to stimulate cloned macrophages to produce significant amounts of tumor necrosis factor-α, (interleukin) IL-6, and NO. Pronounced enhancement of IL-6 production by peritoneal cells was observed when cultured with those extracts, whereas, effects were not noted in spleen and Peyer's patch cell cultures from mice. Based on the results, it appears that, as a group, the lactic acid bacteria were capable of stimulating macrophages and possibly other immune cells to produce cytokines and NO, and both their cell walls and cytoplasm contributed to these capacities.

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