Identification and Antimicrobial Susceptibility of Lactic Acid Bacteria from Retail Fermented Foods

One important safety criterion of using lactic acid bacteria (LAB) in food applications is to ensure that they do not carry transferable antimicrobial resistance (AR) determinants. In this study, 63 LAB belonging to six genera, Streptococcus, Lactobacillus, Lactococcus, Enterococcus, Leuconostoc, and Pediococcus, were recovered from 28 retail fermented food products in Maryland, identified to species with 16S–23S rRNA spacer PCRs, and characterized for antimicrobial susceptibility against eight antimicrobials. Besides intrinsic resistance to ciprofloxacin or vancomycin in some lactobacilli, tetracycline resistance was observed in two Streptococcus thermophilus isolates from one cheese and one sour cream sample and was associated with the presence of a nonconjugative tet(S) gene. The results indicated a low level of AR among naturally occurring and starter LAB cultures in fermented dairy and meat products in the United States; therefore, the probability for foodborne LAB to serve as reservoirs of AR is low. Further studies involving a larger sample size are needed to assess the potential risk of AR gene transfer from LAB in fermented food products.

Download Full-text

Lactic Acid Bacteria: Food Safety and Human Health Applications

Dairy ◽

10.3390/dairy1030015 ◽

2020 ◽

Vol 1 (3) ◽

pp. 202-232

Author(s):

Raphael D. Ayivi ◽

Rabin Gyawali ◽

Albert Krastanov ◽

Sulaiman O. Aljaloud ◽

Mulumebet Worku ◽

...

Keyword(s):

Lactic Acid ◽

Food Safety ◽

Lactic Acid Bacteria ◽

Human Health ◽

Food Products ◽

Industrial Applications ◽

Fermented Food ◽

Fermented Foods ◽

Probiotic Properties ◽

Probiotic Lactic Acid Bacteria

Research on lactic acid bacteria has confirmed how specific strains possess probiotic properties and impart unique sensory characteristics to food products. The use of probiotic lactic acid bacteria (LAB) in many food products, thus confers various health benefits to humans when they are frequently consumed in adequate amounts. The advent of functional food or the concept of nutraceuticals objectively places more emphasis on seeking alternatives to limit the use of medications thus promoting the regular consumption of fermented foods. Probiotic use has thus been recommended to fulfill the role of nutraceuticals, as no side effects on human health have been reported. Probiotics and lactic acid bacteria can boost and strengthen the human immune system, thereby increasing its resistance against numerous disease conditions. Consumer safety and confidence in dairy and fermented food products and the desire of the food industry to meet the sensory and health needs of consumers, has thus increased the demand for probiotic starter cultures with exceptional performance coupled with health benefiting properties. The potential of probiotic cultures and lactic acid bacteria in many industrial applications including fermented food products generally affects product characteristics and also serves as health-promoting foods for humans. The alleviation of lactose intolerance in many populations globally has been one of the widely accepted health claims attributed to probiotics and lactic acid bacteria, although many diseases have been treated with probiotic lactic acid bacteria and have been proven with scientific and clinical studies. The aim of our review was to present information related to lactic acid bacteria, the new classification and perspectives on industrial applications with a special emphasis on food safety and human health.

Download Full-text

Large-scale genome-wide analysis links lactic acid bacteria from food with the gut microbiome

Nature Communications ◽

10.1038/s41467-020-16438-8 ◽

2020 ◽

Vol 11 (1) ◽

Cited By ~ 10

Author(s):

Edoardo Pasolli ◽

Francesca De Filippis ◽

Italia E. Mauriello ◽

Fabio Cumbo ◽

Aaron M. Walsh ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Gut Microbiome ◽

Large Scale ◽

Streptococcus Thermophilus ◽

Fermented Food ◽

Fermented Foods ◽

Genome Wide Analysis ◽

Genome Wide ◽

Stool Samples

Abstract Lactic acid bacteria (LAB) are fundamental in the production of fermented foods and several strains are regarded as probiotics. Large quantities of live LAB are consumed within fermented foods, but it is not yet known to what extent the LAB we ingest become members of the gut microbiome. By analysis of 9445 metagenomes from human samples, we demonstrate that the prevalence and abundance of LAB species in stool samples is generally low and linked to age, lifestyle, and geography, with Streptococcus thermophilus and Lactococcus lactis being most prevalent. Moreover, we identify genome-based differences between food and gut microbes by considering 666 metagenome-assembled genomes (MAGs) newly reconstructed from fermented food microbiomes along with 154,723 human MAGs and 193,078 reference genomes. Our large-scale genome-wide analysis demonstrates that closely related LAB strains occur in both food and gut environments and provides unprecedented evidence that fermented foods can be indeed regarded as a possible source of LAB for the gut microbiome.

Download Full-text

Positive interactions between lactic acid bacteria promoted by nitrogen-based nutritional dependencies

Applied and Environmental Microbiology ◽

10.1128/aem.01055-21 ◽

2021 ◽

Author(s):

Fanny Canon ◽

Marie-Bernadette Maillard ◽

Gwénaële Henry ◽

Anne Thierry ◽

Valérie Gagnaire

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Volatile Compound ◽

Nitrogen Sources ◽

Food Products ◽

Defined Medium ◽

Fermented Food ◽

Strong Interactions ◽

Positive Interactions ◽

Carbohydrate Consumption

Nutritional dependencies, especially those regarding nitrogen sources, govern numerous microbial positive interactions. As for lactic acid bacteria (LAB), responsible for the sanitary, organoleptic, and health properties of most fermented products, such positive interactions have previously been studied between yogurt bacteria. However, they have never been exploited to create artificial co-cultures of LAB that would not necessarily coexist naturally, i.e from different origins. The objective of this study was to promote LAB positive interactions, based on nitrogen dependencies in co-cultures, and to investigate how these interactions affect some functional outputs, e.g. acidification rates, carbohydrate consumption, and volatile compound production. The strategy was to exploit both proteolytic activities and amino acid auxotrophies of LAB. A chemically defined medium was thus developed to specifically allow the growth of six strains used, three proteolytic and three non-proteolytic. Each of the proteolytic strains, Enterococcus faecalis CIRM-BIA2412, Lactococcus lactis NCDO2125, and CIRM-BIA244, was co-cultured with each one of the non-proteolytic LAB strains: L. lactis NCDO2111, Lactiplantibacillus plantarum CIRM-BIA465 and CIRM-BIA1524. Bacterial growth was monitored using compartmented chambers to compare growth in mono- and co-cultures. Acidification, carbohydrate consumption and volatile compound production was evaluated in direct co-cultures. Each proteolytic strain induced different types of interactions: either strongly positive, weakly positive, or no interactions, with E. faecalis CIRM-BIA2412, L. lactis NCDO2125 and L. lactis CIRM-BIA244, respectively. Strong interactions were associated with higher concentrations in tryptophan, valine, phenylalanine, leucine, isoleucine, and peptides. They led to faster acidification rates, lower pH, higher raffinose utilization and concentrations in five volatile compounds. Importance: Lactic acid bacteria (LAB) interactions are often studied in association with yeasts or propionibacteria in various fermented food products and the mechanisms underlying their interactions are being quite well characterized. Concerning interactions between LAB, they have mainly been investigated to test antagonistic interactions. Understanding how they can positively interact could be useful in multiple food-related fields: production of fermented food products with enhanced functional properties or fermentation of new food matrices. This study investigates the exploitation of the proteolytic activity of LAB strains to promote positive interactions between proteolytic and non-proteolytic strains. The results suggest that proteolytic LAB do not equally stimulate non-proteolytic LAB and that the stronger the interactions between LAB are, the more functional outputs we can expect. Thus, this study gives insight into how to create new associations of LAB strains and to guaranty their positive interactions.

Download Full-text

Metabolism Characteristics of Lactic Acid Bacteria and the Expanding Applications in Food Industry

Frontiers in Bioengineering and Biotechnology ◽

10.3389/fbioe.2021.612285 ◽

2021 ◽

Vol 9 ◽

Author(s):

Yaqi Wang ◽

Jiangtao Wu ◽

Mengxin Lv ◽

Zhen Shao ◽

Meluleki Hungwe ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Food Industry ◽

Short Chain Fatty Acids ◽

Fermented Food ◽

The Body ◽

Fermented Foods ◽

Metabolic Characteristics ◽

The One

Lactic acid bacteria are a kind of microorganisms that can ferment carbohydrates to produce lactic acid, and are currently widely used in the fermented food industry. In recent years, with the excellent role of lactic acid bacteria in the food industry and probiotic functions, their microbial metabolic characteristics have also attracted more attention. Lactic acid bacteria can decompose macromolecular substances in food, including degradation of indigestible polysaccharides and transformation of undesirable flavor substances. Meanwhile, they can also produce a variety of products including short-chain fatty acids, amines, bacteriocins, vitamins and exopolysaccharides during metabolism. Based on the above-mentioned metabolic characteristics, lactic acid bacteria have shown a variety of expanded applications in the food industry. On the one hand, they are used to improve the flavor of fermented foods, increase the nutrition of foods, reduce harmful substances, increase shelf life, and so on. On the other hand, they can be used as probiotics to promote health in the body. This article reviews and prospects the important metabolites in the expanded application of lactic acid bacteria from the perspective of bioengineering and biotechnology.

Download Full-text

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

Microorganisms ◽

10.3390/microorganisms7120709 ◽

2019 ◽

Vol 7 (12) ◽

pp. 709 ◽

Cited By ~ 4

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.

Download Full-text

Effects of Sodium Chloride on Tyramine Production in a Fermented Food Model and its Inhibition by Tyrosine-degrading Lactobacillus plantarum JA-1199

CHIMIA International Journal for Chemistry ◽

10.2533/chimia.2020.391 ◽

2020 ◽

Vol 74 (5) ◽

pp. 391-397

Author(s):

Janine Anderegg ◽

Florentin Constancias ◽

Leo Meile

Keyword(s):

Lactic Acid ◽

Sodium Chloride ◽

Lactic Acid Bacteria ◽

Lactobacillus Plantarum ◽

Chloride Concentration ◽

Fermented Food ◽

Starter Cultures ◽

Fermented Foods ◽

Bacterial Strains ◽

Safety Level

Tyramine is a health-adverse biogenic amine, which can accumulate in fermented foods like cheese by decarboxylation of the free amino acid tyrosine by either starter cultures or resident microbes such as lactic acid bacteria including Enterococcus spp., respectively. Our study aimed to show the effect of sodium chloride concentrations on tyramine production as well as to characterise bacterial strains as anti-tyramine biocontrol agents in a 2 mL micro-cheese fermentation model. The effect of sodium chloride on tyramine production was assayed with tyramine producing strains from eight different species or subspecies. Generally, an increase in sodium chloride concentration enhanced tyramine production, e.g. from 0% to 1.5% of sodium chloride resulted in an increase of tyramine of 870% with a Staphylococcus xylosus strain. In the biocontrol screening among lactic acid bacteria, a Lactobacillus plantarum JA-1199 strain was screened that could consume in successful competition with other resident bacteria tyrosine in the micro-cheese model as a source of energy gain. Thereby tyramine accumulation was reduced between 4% to 99%. The results of this study disclose a feasible strategy for decreasing tyramine concentration and increasing the safety level of fermented food. It is an example of development and application of bacterial isolates as starter or protective cultures in food, a biocontrol topic, which Oreste Ghisalba – in his project evaluation function of SNF and later on CTI – was promoting with great emphasis in our ETH Food Biotechnology research group.

Download Full-text

Determining probiotic potential of exopolysaccharide producing lactic acid bacteria isolated from vegetables and traditional Indian fermented food products

Food Bioscience ◽

10.1016/j.fbio.2013.10.002 ◽

2014 ◽

Vol 5 ◽

pp. 27-33 ◽

Cited By ~ 43

Author(s):

Ami Patel ◽

J.B. Prajapati ◽

Olle Holst ◽

Asa Ljungh

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Food Products ◽

Fermented Food ◽

Probiotic Potential

Download Full-text

Isolation and Characterization of Lactic Acid Bacteria Isolated from Fermented Food of North-West Himalayas

Journal of Pure and Applied Microbiology ◽

10.22207/jpam.15.3.50 ◽

2021 ◽

Author(s):

Heenu Sharma ◽

Jasveen Bajwa

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Pathogenic Bacteria ◽

Biochemical Characterization ◽

Antagonistic Activity ◽

Fermented Food ◽

Fermented Foods ◽

North West ◽

The North ◽

Isolation And Characterization

Lactic acid bacteria (LAB) are ubiquitous and are one of the major microbial groups involved in the fermentation of various types of food. They are the most dominant microbes present in milk or milk products and fermented foods where they play vital roles in both the manufacturing and ripening processes. Kaladhi is one of the traditional fermented products of the North-West Himalaya region. It is a hard and dry cheese. In our research, a total of 9 isolates was isolated and was evaluated on the basis of preliminary characterization viz. morphological as well as biochemical characterization and was examined for their antagonistic activity against following pathogens. On the basis of their maximum antagonistic potential against food-borne pathogenic bacteria, isolate K1 is characterized by 16S rRNA sequencing. The isolate was identified as Lactobacillus paracasei subsp. Tolerans strain NBRC 15906 K1|MN814072|.This research was aimed to study the unexplored microflora of Kaladhi and to determine its probiotic potential.

Download Full-text