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•We evaluated AFM1 adsorption by LAB and S. cerevisiaein cheese during 30 days storage.•Lactic acid bacteria decrease 94% of AFM1in cheese at day 10.•S.cerevisiaedecrease 100% of ...AFM1in cheese at day 20.•Lactic acid bacteria and S.cerevisiaedecrease 100% of AFM1in cheese at day 10.•Heat-killed cells of LAB and S.cerevisiaemay be used to reduce AFM1 exposure by cheese.
The purpose of this study was to evaluate the ability of heat-killed cells (121 °C, 10 min) from two strains of lactic acid bacteria (LAB) (Lactobacillus rhamnosus and Lactococcus lactis) and one strain of yeast (Saccharomyces cerevisiae), alone or in combination, to reduce the levels of aflatoxin M1 (AFM1) in Frescal cheese during 30 days of storage. The experimental design was totally randomized, in a 2 × 2 × 2 factorial arrangement, corresponding to two levels of LAB (0 and L. rhamnosus at 1010 cells/kg + L. lactis at 1010 cells/kg), two levels of S. cerevisiae in milk (0 and 1010 yeast cells/kg) and two AFM1 levels (0 and 0.5 µg/kg) added to the cheese curd, totaling 8 treatments with three replicates per treatment. AFM1 levels in Frescal cheese were evaluated by using a high-performance liquid chromatography. Cheese fat and protein contents were not affected (P > 0.05) by any of the treatments, and only pH decreased (P < 0.05) in all treatments from days 2 to 30 of storage (usual shelf life of this type of cheese). AFM1 levels detected in contaminated cheeses decreased on day 2 of storage, varying from 0.09 µg/kg (cheese with addition of bacterial cells) to 0.29 µg/kg (no addition of LAB or yeast cells), this may have occurred due to loss of AFM1 in the Frescal cheese whey. The concentrations of detected AFM1 decreased (P < 0.05) in all treatments from days 2 to 10 of storage, and the maximum percentage reduction of the detectable levels (100%) was achieved after 10 and 20 days of storage in cheeses containing LAB and yeast cells, or prepared with yeast cells alone, respectively. The addition of heat-killed LAB (cells of L. rhamnosus and L. lactis) and Saccharomyces cerevisiae alone or in combination, has a potential ability for adsorbing the AFM1 in Frescal cheese during 30 days of storage.
Grana Padano (GP) is the most appreciated and marketed cheese with Protected Designation of Origin in the world. The use of raw milk, the addition of undefined cultures (defined as 'sieroinnesto ...naturale'), the peculiar manufacturing proces, and the long ripening make the cheese microbiota play a decisive role in defining the quality and the organoleptic properties of the product. The knowledge on the microbial diversity associated with GP has been the subject, in recent years, of several studies aimed at understanding its composition and characteristics in order, on the one hand, to improve its technological performances and, on the other hand, to indirectly enhance the nutritional quality of the product. This review aims to briefly illustrate the main available knowledge on the composition and properties of the GP microbiota, inferred from dozens of studies carried out by both classical microbiology techniques and metagenomic analysis. The paper will essentially, but not exclusively, be focused on the lactic acid bacteria (LAB) derived from starter (SLAB) and the non-starter bacteria, both lactic (NSLAB) and non-lactic, of milk origin.
Beta-lactoglobulin (β-LG) is considered to be the major allergenic protein in milk. Lactic acid bacteria (LAB) possess a protein hydrolysis system that holds great promise for hydrolyzing β-LG and ...reducing its allergenicity. Therefore, this study aimed to screen LAB with β-LG hydrolysis activity from Yunnan traditional fermented foods. The results showed that Pediococcus pentosaceus C1001, Pediococcus acidilactici E1601–1, and Lactobacillus paracasei E1601–2, could effectively hydrolyze β-LG and further reduce its sensitization (more than 40%). All 3 lactic acid bacteria hydrolyzed β-LG allergenic fragments V41–K60 and L149–I162. Moreover, they encode a variety of genes related to proteolysis, such as aminopeptidase pepC and pepN, proline peptidase pepIP and endopeptidase pepO, and L. paracasei E1601–2 contains extracellular protease coding gene prtP. And they encode a variety of genes associated with hydrolyzed proteins. The 3 strains screened in this study can be used to develop hypoallergenic dairy products.
Lactic Acid Bacteria (LAB) have a long history of safe use in milk fermentation and are generally recognized as health-promoting microorganisms when present in fermented foods. LAB are also important ...components of the human intestinal microbiota and are widely used as probiotics. Considering their safe and health-beneficial properties, LAB are considered appropriate vehicles that can be genetically modified for food, industrial and pharmaceutical applications. Here, this review describes (1) the potential opportunities for application of genetically modified LAB strains in dairy fermentation and (2) the various genomic modification tools for LAB strains, such as random mutagenesis, adaptive laboratory evolution, conjugation, homologous recombination, recombineering, and CRISPR (clustered regularly interspaced short palindromic repeat)- Cas (CRISPR-associated protein) based genome engineering. Lastly, this review also discusses the potential future developments of these genomic modification technologies and their applications in dairy fermentations.
This study aimed to analyze the dynamics of biomass growth, lactic acid production, and glucose consumption for three microorganisms; Weissella cibaria IBUN 090–03684, Lactobacillus pantarum IBUN ...090–03774, and Lactobacillus pantarum IBUN 04139 by using an extended logistic model. The microorganisms were cultivated in a 1 L bioreactor with pH control by using MRS medium at 37 ∘C for 24 h at 100 rpm. Weissella cibaria IBUN 090–03684 exhibited the highest product yield (1.26 gg−1), followed by Lactobacillus plantarum IBUN 04139 (0.96 gg−1), and Lactobacillus plantarum IBUN 090–03774 (0.90 gg−1), respectively. The results indicate that Weissella cibaria IBUN 090–03684 holds significant potential for large-scale lactic acid production. Furthermore, the reported modeling strategy fits well with experimental data for the three microorganisms evaluated.
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•The logistics function is a good option for estimating kinetic parameters.•W. cibaria IBUN 090–03684 is a good option for large scale lactic acid production.•Lb. plantarum IBUN 04139 has the highest lactic acid production rate.•PLA from microbial lactic acid production can replace the plastic packaging.
Resistance to antibiotics is escalating and threatening humans and animals worldwide. Different countries have legislated or promoted the ban of antibiotics as growth promoters in livestock and ...aquaculture to reduce this phenomenon. Therefore, to improve animal growth and reproduction performance and to control multiple bacterial infections, there is a potential to use probiotics as non-antibiotic growth promoters. Lactic acid bacteria (LAB) offer various advantages as potential probiotics and can be considered as alternatives to antibiotics during food-animal production. LAB are safe microorganisms with abilities to produce different inhibitory compounds such as bacteriocins, organic acids as lactic acid, hydrogen peroxide, diacetyl, and carbon dioxide. LAB can inhibit harmful microorganisms with their arsenal, or through competitive exclusion mechanism based on competition for binding sites and nutrients. LAB endowed with specific enzymatic functions (amylase, protease…) can improve nutrients acquisition as well as animal immune system stimulation. This review aimed at underlining the benefits and inputs from LAB as potential alternatives to antibiotics in poultry, pigs, ruminants, and aquaculture production.
Fructophilic lactic acid bacteria (FLAB) are a recently discovered group, consisting of a few
and
species. Because of their unique characteristics, including poor growth on glucose and preference of ...oxygen, they are regarded as "unconventional" lactic acid bacteria (LAB). Their unusual growth characteristics are due to an incomplete gene encoding a bifunctional alcohol/acetaldehyde dehydrogenase (
). This results in the imbalance of NAD/NADH and the requirement of additional electron acceptors to metabolize glucose. Oxygen, fructose, and pyruvate are used as electron acceptors. FLAB have significantly fewer genes for carbohydrate metabolism than other LAB, especially due to the lack of complete phosphotransferase system (PTS) transporters. They have been isolated from fructose-rich environments, including flowers, fruits, fermented fruits, and the guts of insects that feed on plants rich in fructose, and are separated into two groups on the basis of their habitats. One group is associated with flowers, grapes, wines, and insects, and the second group is associated with ripe fruits and fruit fermentations. Species associated with insects may play a role in the health of their host and are regarded as suitable vectors for paratransgenesis in honey bees. Besides their impact on insect health, FLAB may be promising candidates for the promotion of human health. Further studies are required to explore their beneficial properties in animals and humans and their applications in the food industry.
The present research was focused on probiotic characterization of lactic acid bacteria from fermented foods and beverage of Ladakh. Twenty five lactic acid bacteria were examined in vitro for ...potential probiotic properties based on their low pH tolerance, bile-salt resistance, lysozyme tolerance, cholesterol removal, hydrophobicity, autoaggragation, production of antimicrobial substances, exopolysaccharide production, β-galactosidase activity and haemolytic activity. The outcome of these studied parameters was used as input data for a principal component analysis (PCA) to select the most promising isolate and ten most potential probiotic isolates were identified through 16S rDNA sequencing. On the basis of PCA, isolate 84 (Lactobacillus plantarum KJ722784) showed similar trend to Lactobacillus casei Shirota used as reference strain in terms of probiotic properties. Fermented milk sample inoculated with L. plantarum KJ722784 exhibited decrease in viable count during storage at 4 °C on day 28. However, the survival count is greater than 7 log CFU/ml which is higher than the requirement of 6 log CFU/ml to exhibit health benefit.
•LAB from fermented foods and beverage of Ladakh, India were characterized.•Principal component analysis (PCA) used to select the most promising isolate.•Isolates 29, 55, 72 and 84 were the most promising probiotic candidates.
Kimchi, a traditional Korean food made by the fermentation of vegetables, has become popular globally because of its organoleptic, beneficial, and nutritional properties. Spontaneous kimchi ...fermentation in unsterilized raw materials leads to the growth of various lactic acid bacteria (LAB), which results in variations in the taste and sensory qualities of kimchi products and difficulties in the standardized industrial production of kimchi. Raw materials, kimchi varieties, ingredients, and fermentation conditions have significant effects on the microbial communities and fermentative characteristics of kimchi during fermentation. Heterofermentative LAB belonging to the genera Leuconostoc, Lactobacillus, and Weissella are likely to be key players in kimchi fermentation and have been subjected to genomic and functional studies to gain a better understanding of the fermentation process and beneficial effects of kimchi. The use of starter cultures has been considered for the industrial production of high quality, standardized kimchi. Here, we review the composition and biochemistry of kimchi microflora communities, functional and genomic studies of kimchi LAB, and perspectives for industrial kimchi production.
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