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Journal of Microbiology and... Jul 2020This study was focused on developing and obtaining a kimchi starter for use in commercial kimchi production. Kimchi varieties made with selected starters are of high...
This study was focused on developing and obtaining a kimchi starter for use in commercial kimchi production. Kimchi varieties made with selected starters are of high quality, have high levels of mannitol, and extended shelf life. The starters were screened for properties such as mannitol production, low gas/acid production, and acid resistance. Finally, kimchi fermentation testing was performed using selected LAB starters. Kimchi samples were prepared with lactic acid bacteria (LAB) starters, including PBio03 and PBio104. The LAB starters are isolated from kimchi and can grow under pH 3.0 and low temperature conditions of 5°C. Four kimchi samples were fermented and stored for 28 days at 5°C. The kimchi samples made with starters (PBio03 and PBio104) had better quality (production of mannitol and maintenance of heterofermentative LAB dominance) than the non-starter kimchi samples. In the starter kimchi, was the dominant LAB, comprising 80% and 70% of total LAB counts at 7 and 21 days, respectively. Mannitol content of the kimchi with PBio03 was 1,423 ± 19.1 mg/ 100 g at 28 days, which was higher than that of the non-starter kimchi sample (1,027 ± 12.2 mg/100 g). These results show the possibility of producing kimchi with improved qualities using PBio03 and PBio104 as starters.
Topics: DNA, Bacterial; Fermentation; Fermented Foods; Food Microbiology; Hydrogen-Ion Concentration; Lactobacillales; Leuconostoc mesenteroides; Mannitol; Taste
PubMed: 32270659
DOI: 10.4014/jmb.2001.01011 -
Journal of Microbiology and... Jun 2018Influenza viruses that cause recurrent seasonal epidemics to humans can be controlled with vaccine and antiviral therapy. However, the medical treatments often exhibit...
Influenza viruses that cause recurrent seasonal epidemics to humans can be controlled with vaccine and antiviral therapy. However, the medical treatments often exhibit limited efficacy in the elderly or immunosuppressed individuals. In these cases, daily uptake of probiotic microbes may be an option to bring in health benefits against influenza. Here, we demonstrate the effects of probiotics (Lp) and (Lm) against seasonal and avian influenza viruses. As assessed by the plaque size reduction of human H1N1 and avian influenza H7N9 viruses, including green fluorescent protein-tagged H1N1 strain in cells, the selected Lp and Lm strains restrained viral replication in mouse lungs with statistical significance. Against lethal viral challenge, the Lp and Lm strains exhibited their beneficial effects by increasing the mean days and rates of survival of infected mice. These results suggest that, despite rather narrow ranges of protective efficacy, the dietary supplement of and probiotics may promote health benefits against influenza.
Topics: Animals; Antiviral Agents; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H7N9 Subtype; Lactobacillus plantarum; Leuconostoc mesenteroides; Lung; Mice; Orthomyxoviridae Infections; Probiotics; Survival Analysis; Treatment Outcome; Viral Load; Viral Plaque Assay; Virus Replication
PubMed: 29847863
DOI: 10.4014/jmb.1804.04001 -
Food Science and Biotechnology Jun 2020The objective of this study was to track intentionally inoculated (11251) and (B151) strains in kimchi using random amplified polymorphic DNA (RAPD), repetitive...
The objective of this study was to track intentionally inoculated (11251) and (B151) strains in kimchi using random amplified polymorphic DNA (RAPD), repetitive element palindromic PCR (rep-PCR), and comparative housekeeping gene sequences analysis. The 16S rRNA gene provided species-level information for 30 colonies randomly picked from kimchi inoculated with strains 11251 and B151. Out of 30 colonies, one colony was matched to strain 11251, and two colonies were found identical to strain B151 reference strain in inoculated kimchi. Notably, among the three tools, strain 11251 was best tracked by comparative gene sequence analysis, while strain B151 tracked by all three tools. Our results suggest that the gene sequence analysis is a more reliable tool for tracking of desired strains than RAPD and rep-PCR. Based on the findings, it is recommended that gene sequence analysis could be used to avoid misuse of industrially useful strains within the growing food industry.
PubMed: 32523791
DOI: 10.1007/s10068-019-00719-0 -
Food Science & Nutrition Nov 2020Di-n-butyl phthalate (DBP) poses a risk to humans as a ubiquitous environmental contaminant. A strain of DM12 was chosen from lactic acid bacteria strains to study the...
Di-n-butyl phthalate (DBP) poses a risk to humans as a ubiquitous environmental contaminant. A strain of DM12 was chosen from lactic acid bacteria strains to study the DBP binding mechanisms. Adsorption of DBP by strain DM12 reached the highest binding rate of 87% after 11 hr of incubation, which could be explained by pseudo-second-order kinetics. The adsorption isotherm coincided with the model of Langmuir-Freundlich, indicating physical and chemical adsorption processes involved. Further, NaIO and TCA treatments were used to analyze the DBP binding mechanism of strain DM12, which indicated that peptidoglycan on the bacterial cell wall was involved in the process. The O-H, C-O, and N-H bonds were possibly involved in the binding process as the main functional groups.
PubMed: 33282266
DOI: 10.1002/fsn3.1908 -
Foods (Basel, Switzerland) May 2023strains are common contributors in fermented foods producing a wide variety of polysaccharides from sucrose through glycosyltransferases (GTFs). These polymers have...
strains are common contributors in fermented foods producing a wide variety of polysaccharides from sucrose through glycosyltransferases (GTFs). These polymers have been proposed as protective barriers against acidity, dehydration, heat, and oxidative stress. Despite its presence in many traditional fermented products and their association with food functional properties, regulation of GTFs expression in is still poorly understood. The strain ATCC 8293 contains three glucansucrases genes not found in operons, and three fructansucrases genes arranged in two operons, and -, a Glycoside-hydrolase. We described the first differential gene expression analysis of this strain when cultivated in different carbon sources. We observed that while GTFs are expressed in the presence of most sugars, they are down-regulated in xylose. We ruled out the regulatory effect of CcpA over GTFs and did not find regulatory elements with a direct effect on glucansucrases in the condition assayed. Our findings suggest that only operon is repressed in xylose by LexA and that both fructansucrases operons can be regulated by the VicK/VicR system and PerR. It is essential to further explore the effect of environmental conditions in bacteria to better understand GTFs regulation and polymer function.
PubMed: 37174431
DOI: 10.3390/foods12091893 -
Microorganisms Jul 2021In many dairy products, spp. is a natural part of non-starter lactic acid bacteria (NSLAB) accounting for flavor development. However, data on the genomic diversity of...
In many dairy products, spp. is a natural part of non-starter lactic acid bacteria (NSLAB) accounting for flavor development. However, data on the genomic diversity of spp. isolates obtained from cheese are still scarce. The focus of this study was the genomic characterization of spp. obtained from different traditional Montenegrin brine cheeses with the aim to explore their diversity and provide genetic information as a basis for the selection of strains for future cheese production. In 2019, sixteen spp. isolates were obtained from white brine cheeses from nine different producers located in three municipalities in the northern region of Montenegro. All isolates were identified as Classical multilocus sequence tying (MLST) and core genome (cg) MLST revealed a high diversity of the Montenegrin cheese isolates. All isolates carried genes of the bacteriocin biosynthetic gene clusters, eight out of 16 strains carried the CDEFG operon, 14 carried and all 16 isolates carried and , genes involved in forming important aromas and flavor compounds. Safety evaluation indicated that isolates carried no pathogenic factors and no virulence factors. In conclusion, isolates from Montenegrin traditional cheeses displayed a high genetic diversity and were unrelated to strains deposited in GenBank.
PubMed: 34442691
DOI: 10.3390/microorganisms9081612 -
Foods (Basel, Switzerland) Feb 2022includes strains used as starter and/or adjunct cultures for the production of several fermented foods. In this study, the effect of anaerobic and respiratory...
includes strains used as starter and/or adjunct cultures for the production of several fermented foods. In this study, the effect of anaerobic and respiratory cultivations, as well as of citrate supplementation and different pH values, was evaluated on growth, biomass, metabolite, and enzymatic activities (pyruvate oxidase, POX; NADH-dependent oxidase, NOX; NADH-dependent peroxidase, NPR) of subsp. E30. We compared the respiration-increased growth rate and biomass production of E30 to anaerobic cultivation. A supplementation of citrate impaired the growth rate of the respiratory cells. As expected, anaerobic cultures did not consume oxygen, and a similar trend in oxygen uptake was observed in respiratory cultures. The aerobic incubation caused changes in the metabolic pattern, reducing the production of ethanol in favour of acetic acid. Citrate was already exhausted in the exponential phase and did not affect the yields in acetic acid and ethanol. NOX activity increased in the presence of oxygen, while catalase was also detected in the absence of hemin. The absence of HO suggested its degradation by NPR and catalase. Respiratory cultivation provided benefits (increase in growth rate, biomass, and activity in antioxidant enzymes) for E30. Therefore, the exploitation of respiratory phenotypes may be useful for the formulation of competitive starter or adjunct cultures.
PubMed: 35206012
DOI: 10.3390/foods11040535 -
Data in Brief Apr 2023Kimchi, a traditional Korean fermented food, contains many lactic acid bacteria. KNU-2 strain with low-temperature tolerance and MBEL1842 with antibacterial activity...
Kimchi, a traditional Korean fermented food, contains many lactic acid bacteria. KNU-2 strain with low-temperature tolerance and MBEL1842 with antibacterial activity were isolated from kimchi. The genomes of KNU-2 and MBEL1842 are composed of one circular chromosomal genome of 1,973,419 bp (37.9% G+C content) and 1,887,056 bp (37.9% G+C content), as well as four and one plasmids, respectively, The sequence data of the strains were deposited in GenBank under the accession numbers CP089782 ( KNU-2) and CP086020 ( MBEL1842).
PubMed: 36819902
DOI: 10.1016/j.dib.2023.108919 -
Journal of Dairy Science Sep 1994Leuconostoc spp. are lactic acid bacteria that are commonly associated with foods and that are used as starter bacteria in some dairy fermentations. Lactic acid bacteria... (Review)
Review
Leuconostoc spp. are lactic acid bacteria that are commonly associated with foods and that are used as starter bacteria in some dairy fermentations. Lactic acid bacteria are inhibitory to other bacteria because of pH, organic acids, hydrogen peroxide, and other chemicals produced during their growth, including bacteriocins. Bacteriocin production by Leuconostoc spp. was first observed in the 1950s, but only since 1984, when antagonistic activity of Leuconostoc spp. was reported, have more extensive studies of bacteriocins produced by Leuconostoc spp. been conducted, including mesentericin Y105, produced by Leuconostoc mesenteroides spp. mesenteroides; leucocin A-UAL 187, produced by Leuconostoc gelidum; carnosin 44A, produced by Leuconostoc carnosum; and leuconocin S, produced by Leuconostoc paramesenteroides. Bacteriocins produced by leuconostocs may or may not be active against other lactic acid bacteria, but all include Listeria in their activity spectra. Mesentericin Y105 is reported to be exclusively active against Listeria spp. The amino acid sequences for leucocin A and mesentericin Y105 have been determined. Despite considerable differences in antibacterial spectra, only two amino acids differ between these bacteriocins. The prevalence of leuconostocs in many adventitious fermentations of food and the use of leuconostocs as starter bacteria in controlled fermentations make the bacteriocins produced by these bacteria of interest as possible food preservatives by addition of the bacteriocin or its producer organism to foods.
Topics: Amino Acid Sequence; Bacteriocins; Leuconostoc; Molecular Sequence Data
PubMed: 7814741
DOI: 10.3168/jds.S0022-0302(94)77214-3 -
Frontiers in Microbiology 2023The emergent human coronavirus SARS-CoV-2 and its resistance to current drugs makes the need for new potent treatments for COVID-19 patients strongly necessary. Dextran...
The emergent human coronavirus SARS-CoV-2 and its resistance to current drugs makes the need for new potent treatments for COVID-19 patients strongly necessary. Dextran sulfate (DS) polysaccharides have long demonstrated antiviral activity against different enveloped viruses . However, their poor bioavailability has led to their abandonment as antiviral candidates. Here, we report for the first time the broad-spectrum antiviral activity of a DS-based extrapolymeric substance produced by the lactic acid bacterium B512F. Time of addition assays with SARS-CoV-2 pseudoviruses in models confirm the inhibitory activity of DSs in the early stages of viral infection (viral entry). In addition, this exopolysaccharide substance also reports broad-spectrum antiviral activity against several enveloped viruses such as SARS-CoV-2, HCoV229E, HSV-1, in models and in human lung tissue. The toxicity and antiviral capacity of DS from was tested in mouse models which are susceptible to SARS-CoV-2 infection. The described DS, administered by inhalation, a new route of administration for these types of polymers, shows strong inhibition of SARS-CoV-2 infection , significantly reducing animal mortality and morbidity at non-toxic doses. Therefore, we suggest that it may be considered as a potential candidate for antiviral therapy against SARS-CoV-2.
PubMed: 37206325
DOI: 10.3389/fmicb.2023.1185504