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BMC Genomic Data Aug 2022Leuconostoc lactis forms a crucial member of the genus Leuconostoc and has been widely used in the fermentation industry to convert raw material into acidified and...
BACKGROUND
Leuconostoc lactis forms a crucial member of the genus Leuconostoc and has been widely used in the fermentation industry to convert raw material into acidified and flavored products in dairy and plant-based food systems. Since the ecological niches that strains of Ln. lactis being isolated from were truly diverse such as the human gut, dairy, and plant environments, comparative genome analysis studies are needed to better understand the strain differences from a metabolic adaptation point of view across diverse sources of origin. We compared eight Ln. lactis strains of 1.2.28, aa_0143, BIOML-A1, CBA3625, LN19, LN24, WIKIM21, and WiKim40 using bioinformatics to elucidate genomic level characteristics of each strain for better utilization of this species in a broad range of applications in food industry.
RESULTS
Phylogenomic analysis of twenty-nine Ln. lactis strains resulted in nine clades. Whole-genome sequence analysis was performed on eight Ln. lactis strains representing human gastrointestinal tract and fermented foods microbiomes. The findings of the present study are based on comparative genome analysis against the reference Ln. lactis CBA3625 genome. Overall, a ~ 41% of all CDS were conserved between all strains. When the coding sequences were assigned to a function, mobile genetic elements, mainly insertion sequences were carried by all eight strains. All strains except LN24 and WiKim40 harbor at least one intact putative prophage region, and two of the strains contained CRISPR-Cas system. All strains encoded Lactococcin 972 bacteriocin biosynthesis gene clusters except for CBA3625.
CONCLUSIONS
The findings in the present study put forth new perspectives on genomics of Ln. lactis via complete genome sequence based comparative analysis and further determination of genomic characteristics. The outcomes of this work could potentially pave the way for developing elements for future strain engineering applications.
Topics: Fermented Foods; Genomics; Humans; Leuconostoc; Microbiota
PubMed: 35918643
DOI: 10.1186/s12863-022-01074-6 -
Emerging Infectious Diseases Sep 2020Leuconostoc lactis is a glycopeptide-resistant, gram-positive, facultative anaerobic coccus isolated from dairy products, whereas Staphylococcus nepalensis is...
Leuconostoc lactis is a glycopeptide-resistant, gram-positive, facultative anaerobic coccus isolated from dairy products, whereas Staphylococcus nepalensis is coagulase-negative coccus that has not been identified as human pathogen. We report an instructive case of L. lactis and S. nepalensis bacteremia in a 71-year-old man who experienced Boerhaave syndrome after a meal.
Topics: Aged; Anti-Bacterial Agents; Bacteremia; Gram-Positive Bacterial Infections; Humans; Japan; Leuconostoc; Male; Staphylococcus
PubMed: 32818417
DOI: 10.3201/eid2609.191123 -
Microorganisms Jan 2021SBC001, isolated from chive, produces glucansucrase and synthesizes oligosaccharides through its enzymatic activity. This study was conducted to optimize...
SBC001, isolated from chive, produces glucansucrase and synthesizes oligosaccharides through its enzymatic activity. This study was conducted to optimize oligosaccharide production using response surface methodology, analyze the structure of purified oligosaccharides, and investigate the prebiotic effect on 24 bacterial and yeast strains and the anti-inflammatory activity using RAW 264.7 macrophage cells. The optimal conditions for oligosaccharide production were a culture temperature of 30 °C and sucrose and maltose concentrations of 9.6% and 7.4%, respectively. Based on H-NMR spectroscopic study, the oligosaccharides were identified as gluco-oligosaccharides that consisted of 23.63% α-1,4 glycosidic linkages and 76.37% α-1,6 glycosidic linkages with an average molecular weight of 1137 Da. The oligosaccharides promoted the growth of bacterial and yeast strains, including , , , , , and . When lipopolysaccharide-stimulated RAW 264.7 cells were treated with the oligosaccharides, the production of nitric oxide was decreased; the expression of inducible nitric oxide synthase, tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and IL-10 was suppressed; and the nuclear factor-kappa B signaling pathway was inhibited. In conclusion, the gluco-oligosaccharides obtained from SBC001 exhibited a prebiotic effect on six bacterial and yeast strains and anti-inflammatory activity in RAW 264.7 macrophage cells.
PubMed: 33477973
DOI: 10.3390/microorganisms9010200 -
Journal of Microbiology and... Mar 2022has been used as a principal starter in natural kimchi fermentation, but limited research has been conducted on its phages. In this study, prophage distribution and...
has been used as a principal starter in natural kimchi fermentation, but limited research has been conducted on its phages. In this study, prophage distribution and characterization in kimchi-derived strains were investigated, and phage induction was performed. Except for one strain, 16 strains had at least one prophage region with questionable and incomplete regions, which comprised 0.5-6.0% of the bacterial genome. Based on major capsid protein analysis, ten intact prophages and an induced incomplete prophage of CBA3626 belonged to the family and were similar to Lc-Nu-like, sha1-like, phiMH1-like, and TPA_asm groups. Bacterial immunology genes, such as superinfection exclusion proteins and methylase, were found on several prophages. One prophage of CBA3626 was induced using mitomycin C and was confirmed as belonging to the family. Homology of the induced prophage with 21 reported prophages was not high (< 4%), and 47% identity was confirmed only with TPA_asm from sp. isolate ct3pk4. Therefore, it is suggested that from kimchi had diverse prophages with less than 6% genome proportion and some immunological genes. Interestingly, the induced prophage was very different from the reported prophages of other species.
Topics: Fermented Foods; Genomics; Leuconostoc; Prophages
PubMed: 34949750
DOI: 10.4014/jmb.2110.10046 -
Microorganisms May 2023Synbiotics contain health-beneficial bacteria, i.e., probiotics and prebiotics selectively utilized by the probiotics. Herein, three probiotic strains, CCK940, SBC001,...
Synbiotics contain health-beneficial bacteria, i.e., probiotics and prebiotics selectively utilized by the probiotics. Herein, three probiotic strains, CCK940, SBC001, and YRK005, and the oligosaccharides produced by these strains (CCK, SBC, and YRK, respectively) were used to prepare nine synbiotic combinations. Macrophages (RAW 264.7) were treated with these synbiotic combinations and the corresponding lactic acid bacteria and oligosaccharides alone to evaluate the treatments' immunostimulatory activities. The level of nitric oxide (NO) production was significantly higher in the macrophages treated with the synbiotics than in those treated with the corresponding probiotic strains and the oligosaccharide alone. The immunostimulatory activities of the synbiotics increased regardless of the probiotic strain and the type of oligosaccharide used. The expressions of tissue necrosis factor-α, interleukin-1β, cyclooxygenase-2, inducible NO synthase genes, and extracellular-signal-regulated and c-Jun N-terminal kinases were significantly higher in the macrophages treated with the three synbiotics than in those treated with the corresponding strains or with the oligosaccharides alone. These results indicate that the synergistic immunostimulatory activities of probiotics and the prebiotics they produced in the studied synbiotic preparations resulted from the activation of the mitogen-activated protein-kinase-signaling pathway. This study suggests the combined use of these probiotics and prebiotics in the development of synbiotic preparations as health supplements.
PubMed: 37317327
DOI: 10.3390/microorganisms11051354 -
Korean Journal For Food Science of... Oct 2018Although bacteriocins with anti-listerial activity have been isolated from a wide variety of lactic acid bacteria, little is known about those from , a...
Although bacteriocins with anti-listerial activity have been isolated from a wide variety of lactic acid bacteria, little is known about those from , a heterofermentative bacterium that produces diacetyl and exopolysaccharides in dairy foods. In this study, an anti-listerial bacteriocin was isolated from SD501 and characterized. It was particularly potent against and also inhibited . Anti-listerial activity reached a maximum during the early stationary phase and then decreased gradually. The anti-listerial substance was sensitive to proteinase K and ɑ-chymotrypsin, confirming its proteinaceous nature. Its activity remained stable at pH values ranging from 1 to 10. In addition, it was strongly resistant to high temperatures, retaining its activity even after incubation for 15 min at 121℃. The apparent molecular mass of the partially purified anti-listerial bacteriocin was approximately 7 kDa. The characteristics of the SD501 bacteriocin, including its small molecular size (<10 kDa), strong anti-listerial activity, wide pH stability and good thermostability, indicate its classification as a Class IIa bacteriocin.
PubMed: 30479507
DOI: 10.5851/kosfa.2018.e33 -
MicrobiologyOpen Aug 2020High levels of gums such as dextran, produced by Leuconostoc and Lactobacillus spp., have a severe impact on factory throughput and sugar quality. This study aimed to...
High levels of gums such as dextran, produced by Leuconostoc and Lactobacillus spp., have a severe impact on factory throughput and sugar quality. This study aimed to determine the phylogenetic relationships between gum-producing Leuconostoc and Lactobacillus bacteria which were isolated from various locations in a sugarcane processing factory at times when low- and high-dextran raw sugar, respectively, were produced. Phylogenetic analysis of 16S rRNA gene sequences grouped 81 isolates with the type strains of Leuconostoc mesenteroides (subspp. mesenteroides, dextranicum, and cremoris), Leuconostoc pseudomesenteroides, Leuconostoc lactis, and Leuconostoc citreum, respectively. Forty-three isolates clustered with the type strain of Lactobacillus fermentum. The phylogenetic relatedness of the isolates was determined by sequencing and analysis of the housekeeping genes rpoA and dnaA for Leuconostoc spp. and the pheS and tuf genes for the Lactobacillus spp. The rpoA gene proved discriminatory for the phylogenetic resolution of all of the isolated Leuconostoc spp. and the dnaA housekeeping gene was shown to be effective for isolates clustering with the type strains of Leuc. mesenteroides and Leuc. citreum. None of the loci examined permitted differentiation at the subspecies level of Leuc. mesenteroides. Single-locus analysis, as well as the concatenation of the pheS and tuf housekeeping gene sequences, yielded identical phylogenies for the Lactobacillus isolates corresponding to L. fermentum.
Topics: Bacterial Proteins; DNA, Bacterial; DNA-Binding Proteins; DNA-Directed RNA Polymerases; Dextrans; Gene Amplification; Genes, Essential; Lactobacillus; Leuconostoc; Phylogeny; RNA, Ribosomal, 16S; Saccharum; Sequence Analysis, DNA
PubMed: 32496663
DOI: 10.1002/mbo3.1065 -
Applied and Environmental Microbiology Feb 2020This study aimed at establishing the effects of attenuated starters and surface bacteria on various features of caciotta cheese. The cheese undergoes a ripening period...
This study aimed at establishing the effects of attenuated starters and surface bacteria on various features of caciotta cheese. The cheese undergoes a ripening period during which the house microbiota contaminates the surface. Conventional cheese (the control cheese [CC]) is made using only primary starters. Primary starters and attenuated (i.e., unable to grow and synthesize lactic acid) () subsp. were used to produce caciotta cheese without (ATT cheese) or with an inoculum of surface bacteria: (i) () (LL cheese), (ii) (VC cheese), (iii) (SE cheese), (iv) (BX cheese), and (v) a mixture of all four (MIX cheese). Attenuated increased microbial diversity during cheese ripening. At the core, attenuated starter mainly increased indigenous lactococci and group bacteria. At the surface, the main effect was on Autochthonous strains took advantage of the attenuated starter, becoming dominant. Adjunct positively affected group bacteria on the LL cheese surface. Adjunct , , and did not become dominant. Surfaces of VC, SE, and BX cheeses mainly harbored Peptidase activities were higher in cheeses made with attenuated starter than in CC, which had the lowest concentration of free amino acids. Based on the enzymatic activities of adjunct , LL and MIX cheeses exhibited the highest glutamate dehydrogenase, cystathionine-γ-lyase, and esterase activities. As shown by multivariate statistical analyses, LL and MIX cheeses showed the highest similarity for microbiological and biochemical features. LL and MIX cheeses received the highest scores for overall sensory acceptability. This study provides in-depth knowledge of the effects of attenuated starters and surface bacterial strains on the microbiota and related metabolic activities during cheese ripening. The use of attenuated strongly impacted the microbiota assembly of caciotta cheese. This led to improved biochemical and sensory features compared to conventional cheese. Among surface bacterial strains, played a key role in the metabolic activities involved in cheese ripening. This resulted in an improvement of the sensory quality of caciotta cheese. The use of attenuated lactic acid bacteria and the surface adjunct could be a useful biotechnology to improve the flavor formation of caciotta cheese.
Topics: Cheese; Food Microbiology; Lactococcus lactis; Microbiota; Taste
PubMed: 31862717
DOI: 10.1128/AEM.02165-19 -
BMC Microbiology Jul 2020Probiotics are being considered as valuable microorganisms related to human health. Hu sheep is referred as one of the important sheep breeds in China. Goat milk...
BACKGROUND
Probiotics are being considered as valuable microorganisms related to human health. Hu sheep is referred as one of the important sheep breeds in China. Goat milk produced by Hu sheep is characterized with high nutritional value and hypoallergenic in nature. Particularly, this milk contains plenty of milk prebiotic and probiotic bacteria. This study was aimed to scrutinize more bacterial strains from Hu sheep milk with potential probiotic activity.
RESULTS
Based on 16S rRNA sequence analysis, pool of forty bacterial strains were identified and evaluated their antimicrobial activities against Staphylococcus aureus, enterohemorrhagic Escherichia coli (EHEC), Salmonella typhimurium, Listeria monocytogenes enterotoxigenic E. coli (ETEC) and Aeromonas caviae. Four out of these isolated strains demonstrated their efficient bacteriostatic ability and potential healthy properties. We also examined the safety aspects of these bacterial candidates including three Lactococcus lactis strains (named as HSM-1, HSM-10, and HSM-18) and one Leuconostoc lactis strain (HSM-14), and were further evaluated via in vitro tests, including antimicrobial activity, cell surface characteristics (hydrophobicity, co-aggregation, and self-aggregation), heat treatment, antibiotic susceptibility, simulated transport tolerance in the gastrointestinal tract, and acid/bile tolerance. The obtained results revealed that HSM-1, HSM-10, HSM-14, and HSM-18 showed high survival rate at different conditions for example low pH, presence of bovine bile and demonstrated high hydrophobicity. Moreover, HSM-14 had an advantage over other strains in terms of gastrointestinal tract tolerance, antimicrobial activities against pathogens, and these results were significantly better than other bacterial candidates.
CONCLUSION
Hu sheep milk as a source of exploration of potential lactic acid bacteria (LAB) probiotics open the new horizon of probiotics usage from unconventional milk sources. The selected LAB strains are excellent probiotic candidates which can be used for animal husbandry in the future. Rationale of the study was to utilize Hu sheep milk as a source of potential probiotic LABs. The study has contributed to the establishment of a complete bacterial resource pool by exploring the Hu sheep milk microflora.
Topics: Animals; Anti-Bacterial Agents; Bile Acids and Salts; Gastrointestinal Tract; Hydrophobic and Hydrophilic Interactions; Lactobacillales; Microbial Viability; Milk; Phylogeny; Probiotics; RNA, Ribosomal, 16S; Sheep
PubMed: 32723292
DOI: 10.1186/s12866-020-01920-6 -
Frontiers in Microbiology 2022is found in vegetables, fruits, and meat and is used by the food industry in the preparation of dairy products, wines, and sugars. We have previously demonstrated that...
is found in vegetables, fruits, and meat and is used by the food industry in the preparation of dairy products, wines, and sugars. We have previously demonstrated that the dextransucrase of (DsrLL) AV1n produces a high-molecular-weight dextran from sucrose, indicating its potential use as a dextran-forming starter culture. We have also shown that this bacterium was able to produce 10-fold higher levels of dextran at 20°C than at 37°C, at the former temperature accompanied by an increase in gene expression. However, the general physiological response of AV1n to cold temperature in the presence of sucrose, leading to increased production of dextran, has not been yet investigated. Therefore, we have used a quantitative proteomics approach to investigate the cold temperature-induced changes in the proteomic profile of this strain in comparison to its proteomic response at 37°C. In total, 337 proteins were found to be differentially expressed at the applied significance criteria (adjusted -value ≤ 0.05, FDR 5%, and with a fold-change ≥ 1.5 or ≤ 0.67) with 204 proteins overexpressed, among which 13% were involved in protein as well as cell wall, and envelope component biosynthesis including DsrLL. Proteins implicated in cold stress were expressed at a high level at 20°C and possibly play a role in the upregulation of DsrLL, allowing the efficient synthesis of the protein essential for its adaptation to cold. Post-transcriptional regulation of DsrLL expression also seems to take place through the interplay of exonucleases and endonucleases overexpressed at 20°C, which would influence the half-life of the transcript. Furthermore, the mechanism of cold resistance of AV1n seems to be also based on energy saving through a decrease in growth rate mediated by a decrease in carbohydrate metabolism and its orientation toward the production pathways for storage molecules. Thus, this better understanding of the responses to low temperature and mechanisms for environmental adaptation of could be exploited for industrial use of strains belonging to this species.
PubMed: 36713162
DOI: 10.3389/fmicb.2022.1077375