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Alfalfa as a vegetable source of β-carotene: The change mechanism of β-carotene during fermentation.Food Research International (Ottawa,... Oct 2023The objectives of this study were to explore the β-carotene-producing bacteria and ascertain the main factors affecting β-carotene content via investigating the...
The objectives of this study were to explore the β-carotene-producing bacteria and ascertain the main factors affecting β-carotene content via investigating the effects of various additives on β-carotene content, bacterial community succession, and quality of fermented alfalfa, using single-molecule real-time (SMRT) sequencing technology. Fresh alfalfa was fermented without (CON) or with squalene (SQ), the combination of Lactobacillus plantarum and cellulase (LPEN), and the combination of SQ and LPEN (SQLPEN) for 3, 45, and 90 d. The results showed that relative to the fresh alfalfa, extensive β-carotene loss in all groups occurred in the early fermentation phase (3 d) since epiphytic Pantoea agglomerans with the ability to produce β-carotene disappeared and β-carotene was oxidized by lipoxygenase and peroxidase. With the prolonged fermentation days, β-carotene content in all groups increased due to bacterial community succession in the middle and late phases of fermentation (45 and 90 d). The species L. parabuchneri, L. kunkeei, and L. kullabergensis (r = 0.591, 0.366, 0.341, orderly) had positive correlations with β-carotene content (P < 0.05). Bacterial functional potential prediction showed that species L. kunkeei, L. helsingborgensis, and L. kullabergensis had positive (r = 0.478, 0.765, 0.601) correlations with C10-C20 isoprenoid biosynthesis (P < 0.01), and L. helsingborgensis and L. kullabergensis had positive (r = 0.805, 0.522) correlations with β-carotene biosynthesis (P < 0.01). Additionally, the pH and propionic acid (r = -0.567, -0.504) had negative correlations with β-carotene content (P < 0.01). The CON group was preserved well after 90 d, LPEN and SQLPEN further improved fermentation quality. In conclusion, certain Lactobacillus had the potential for β-carotene biosynthesis, and high pH and propionic acid content were the unbenefited factors for β-carotene retention in fermented alfalfa.
Topics: Fermentation; Medicago sativa; Vegetables; beta Carotene
PubMed: 37689873
DOI: 10.1016/j.foodres.2023.113104 -
Genes Nov 2023Maize white spot (MWS), caused by the bacterium , is a serious disease that significantly impacts maize production and productivity. In recent years, outbreaks of white... (Review)
Review
Maize white spot (MWS), caused by the bacterium , is a serious disease that significantly impacts maize production and productivity. In recent years, outbreaks of white spot disease have resulted in substantial maize yield losses in southwest China. Researchers from various countries worldwide have conducted extensive research on this pathogen, including its isolation and identification, the localization of resistance genes, transmission pathways, as well as potential control measures. However, the information related to this disease remains fragmented, and standardized preventive and control strategies have not yet been established. In light of this, this review aims to comprehensively summarize the research findings on MWS, providing valuable insights into understanding its occurrence, prevention, and control measures in the southwestern and southern regions of China while also mitigating the detrimental impact and losses caused by MWS on maize production in China and across the world.
Topics: Zea mays; China
PubMed: 38003004
DOI: 10.3390/genes14112061 -
Archives of Microbiology Aug 2019The genus Pantoea contains a broad range of plant-associated bacteria, including some economically important plant pathogens as well as some beneficial members effective... (Review)
Review
The genus Pantoea contains a broad range of plant-associated bacteria, including some economically important plant pathogens as well as some beneficial members effective as biological control agents of plant pathogens. The most well-characterized representatives of biological control agents from this genus generally produce one or more antimicrobial compounds adding to biocontrol efficacy. Some Pantoea species evaluated as biocontrol agents for fire blight disease of apple and pear produce a histidine-reversible antibiotic. Three commonly studied histidine-reversible antibiotics produced by Pantoea spp. are herbicolin O, MccEh252, and pantocin A. Pantocin A is a novel ribosomally encoded and post-translationally modified peptide natural product. Here, we review the current knowledge on the chemistry, genetics, biosynthesis, and incidence and environmental relevance of pantocin A and related histidine-reversible antibiotics produced by Pantoea.
Topics: Biological Control Agents; Glycopeptides; Pantoea; Peptides; Plant Diseases
PubMed: 30868174
DOI: 10.1007/s00203-019-01647-7 -
Frontiers in Microbiology 2024This paper brings new information about the genome and phenotypic characteristics of strain DBM 3797, isolated from fresh Czech hop () in the Saaz hop-growing region....
BACKGROUND
This paper brings new information about the genome and phenotypic characteristics of strain DBM 3797, isolated from fresh Czech hop () in the Saaz hop-growing region. Although strains are frequently isolated from different materials, there are not usually thoroughly characterized even if they have versatile metabolism and those isolated from plants may have a considerable potential for application in agriculture as a support culture for plant growth.
METHODS
DBM 3797 was cultured under aerobic and anaerobic conditions, its metabolites were analyzed by HPLC and it was tested for plant growth promotion abilities, such as phosphate solubilization, siderophore and indol-3-acetic acid productions. In addition, genomic DNA was extracted, sequenced and assembly was performed. Further, genome annotation, pan-genome analysis and selected genome analyses, such as CRISPR arrays detection, antibiotic resistance and secondary metabolite genes identification were carried out.
RESULTS AND DISCUSSION
The typical appearance characteristics of the strain include the formation of symplasmata in submerged liquid culture and the formation of pale yellow colonies on agar. The genetic information of the strain (in total 4.8 Mb) is divided between a chromosome and two plasmids. The strain lacks any CRISPR-Cas system but is equipped with four restriction-modification systems. The phenotypic analysis focused on growth under both aerobic and anaerobic conditions, as well as traits associated with plant growth promotion. At both levels (genomic and phenotypic), the production of siderophores, indoleacetic acid-derived growth promoters, gluconic acid, and enzyme activities related to the degradation of complex organic compounds were found. Extracellular gluconic acid production under aerobic conditions (up to 8 g/l) is probably the result of glucose oxidation by the membrane-bound pyrroloquinoline quinone-dependent enzyme glucose dehydrogenase. The strain has a number of properties potentially beneficial to the hop plant and its closest relatives include the strains also isolated from the aerial parts of plants, yet its safety profile needs to be addressed in follow-up research.
PubMed: 38389535
DOI: 10.3389/fmicb.2024.1305338 -
PloS One 2021Pantoea agglomerans is a Gram-negative facultative anaerobic bacillus causing a wide range of opportunistic infections in humans including septicemia, pneumonia, septic...
Pantoea agglomerans is a Gram-negative facultative anaerobic bacillus causing a wide range of opportunistic infections in humans including septicemia, pneumonia, septic arthritis, wound infections and meningitis. To date, the determinants of virulence, antibiotic resistance, metabolic features conferring survival and host-associated pathogenic potential of this bacterium remain largely underexplored. In this study, we sequenced and assembled the whole-genome of P. agglomerans KM1 isolated from kimchi in South Korea. The genome contained one circular chromosome of 4,039,945 bp, 3 mega plasmids, and 2 prophages. The phage-derived genes encoded integrase, lysozyme and terminase. Six CRISPR loci were identified within the bacterial chromosome. Further in-depth analysis showed that the genome contained 13 antibiotic resistance genes conferring resistance to clinically important antibiotics such as penicillin G, bacitracin, rifampicin, vancomycin, and fosfomycin. Genes involved in adaptations to environmental stress were also identified which included factors providing resistance to osmotic lysis, oxidative stress, as well as heat and cold shock. The genomic analysis of virulence factors led to identification of a type VI secretion system, hemolysin, filamentous hemagglutinin, and genes involved in iron uptake and sequestration. Finally, the data provided here show that, the KM1 isolate exerted strong immunostimulatory properties on RAW 264.7 macrophages in vitro. Stimulated cells produced Nitric Oxide (NO) and pro-inflammatory cytokines TNF-α, IL-6 and the anti-inflammatory cytokine IL-10. The upstream signaling for production of TNF-α, IL-6, IL-10, and NO depended on TLR4 and TLR1/2. While production of TNF-α, IL-6 and NO involved solely activation of the NF-κB, IL-10 secretion was largely dependent on NF-κB and to a lesser extent on MAPK Kinases. Taken together, the analysis of the whole-genome and immunostimulatory properties provided in-depth characterization of the P. agglomerans KM1 isolate shedding a new light on determinants of virulence that drive its interactions with the environment, other microorganisms and eukaryotic hosts.
Topics: Animals; Anti-Bacterial Agents; Bacterial Typing Techniques; Cytokines; Drug Resistance, Microbial; Enterobacteriaceae Infections; Genomics; Humans; Macrophages; Mice; NF-kappa B; Pantoea; Phylogeny; Plant Diseases; Plasmids; Prophages; RAW 264.7 Cells; Virulence; Virulence Factors
PubMed: 33406073
DOI: 10.1371/journal.pone.0239792 -
Molecular Plant Pathology Oct 2021The endophytic bacterium Pantoea agglomerans DAPP-PG 734 was previously isolated from olive knots caused by infection with Pseudomonas savastanoi pv. savastanoi DAPP-PG...
Synergistic interaction between the type III secretion system of the endophytic bacterium Pantoea agglomerans DAPP-PG 734 and the virulence of the causal agent of olive knot Pseudomonas savastanoi pv. savastanoi DAPP-PG 722.
The endophytic bacterium Pantoea agglomerans DAPP-PG 734 was previously isolated from olive knots caused by infection with Pseudomonas savastanoi pv. savastanoi DAPP-PG 722. Whole-genome analysis of this P. agglomerans strain revealed the presence of a Hypersensitive response and pathogenicity (Hrp) type III secretion system (T3SS). To assess the role of the P. agglomerans T3SS in the interaction with P. savastanoi pv. savastanoi, we generated independent knockout mutants in three Hrp genes of the P. agglomerans DAPP-PG 734 T3SS (hrpJ, hrpN, and hrpY). In contrast to the wildtype control, all three mutants failed to cause a hypersensitive response when infiltrated in tobacco leaves, suggesting that P. agglomerans T3SS is functional and injects effector proteins in plant cells. In contrast to P. savastanoi pv. savastanoi DAPP-PG 722, the wildtype strain P. agglomerans DAPP-PG 734 and its Hrp T3SS mutants did not cause olive knot disease in 1-year-old olive plants. Coinoculation of P. savastanoi pv. savastanoi with P. agglomerans wildtype strains did not significantly change the knot size, while the DAPP-PG 734 hrpY mutant induced a significant decrease in knot size, which could be complemented by providing hrpY on a plasmid. By epifluorescence microscopy and confocal laser scanning microscopy, we found that the localization patterns in knots were nonoverlapping for P. savastanoi pv. savastanoi and P. agglomerans when coinoculated. Our results suggest that suppression of olive plant defences mediated by the Hrp T3SS of P. agglomerans DAPP-PG 734 positively impacts the virulence of P. savastanoi pv. savastanoi DAPP-PG 722.
Topics: Olea; Pantoea; Piperazines; Plant Diseases; Pseudomonas; Type III Secretion Systems; Virulence
PubMed: 34268839
DOI: 10.1111/mpp.13105 -
Frontiers in Microbiology 2023The fermentative production of auxin/indole 3-acetate (IAA) using selected strains can be a promising approach to developing novel plant biostimulants for agriculture...
INTRODUCTION
The fermentative production of auxin/indole 3-acetate (IAA) using selected strains can be a promising approach to developing novel plant biostimulants for agriculture use.
METHODS
By integrating metabolomics and fermentation technologies, this study aimed to define the optimal culture conditions to obtain auxin/IAA-enriched plant postbiotics using strain C1. Metabolomics analysis allowed us to demonstrate that the production of a selected.
RESULTS AND DISCUSSION
Array of compounds with plant growth-promoting- (IAA and hypoxanthine) and biocontrol activity (NS-5, cyclohexanone, homo-L-arginine, methyl hexadecenoic acid, and indole-3-carbinol) can be stimulated by cultivating this strain on minimal saline medium amended with sucrose as a carbon source. We applied a three-level-two-factor central composite design (CCD) based response surface methodology (RSM) to explore the impact of the independent variables (rotation speed and medium liquid-to-flask volume ratio) on the production of IAA and IAA precursors. The ANOVA component of the CCD indicated that all the process-independent variables investigated significantly impacted the auxin/IAA production by train C1. The optimum values of variables were a rotation speed of 180 rpm and a medium liquid-to-flask volume ratio of 1:10. Using the CCD-RSM method, we obtained a maximum indole auxin production of 208.3 ± 0.4 mg IAA/L, which was a 40% increase compared to the growth conditions used in previous studies. Targeted metabolomics allowed us to demonstrate that the IAA product selectivity and the accumulation of the IAA precursor indole-3-pyruvic acid were significantly affected by the increase in the rotation speed and the aeration efficiency.
PubMed: 36970660
DOI: 10.3389/fmicb.2023.1022248 -
Journal of Microbiology and... May 2021Levan is an industrially important, functional biopolymer with considerable applications in the food and pharmaceutical fields owing to its safety and biocompatibility....
Levan is an industrially important, functional biopolymer with considerable applications in the food and pharmaceutical fields owing to its safety and biocompatibility. Here, levan-type exopolysaccharide produced by Pantoea agglomerans ZMR7 was purified by cold ethanol precipitation and characterized using TLC, FTIR, H, and C NMR spectroscopy. The maximum production of levan (28.4 g/l) was achieved when sucrose and ammonium chloride were used as carbon and nitrogen sources, respectively, at 35°C and an initial pH of 8.0. Some biomedical applications of levan like antitumor, antiparasitic, and antioxidant activities were investigated in vitro. The results revealed the ability of levan at different concentrations to decrease the viability of rhabdomyosarcoma and breast cancer cells compared with untreated cancer cells. Levan appeared also to have high antiparasitic activity against the promastigote of . Furthermore, levan had strong DPPH radical scavenging (antioxidant) activity. These findings suggest that levan produced by ZMR7 can serve as a natural biopolymer candidate for the pharmaceutical and medical fields.
Topics: Antineoplastic Agents; Antioxidants; Antiparasitic Agents; Cell Line, Tumor; Cell Proliferation; Culture Media; Fructans; Humans; Leishmania tropica; Pantoea; Polysaccharides, Bacterial
PubMed: 33820887
DOI: 10.4014/jmb.2101.01025 -
Microorganisms Aug 2021The bacterial genus has been widely evaluated as promising bacteria to increase phosphorus (P) availability in soil. The aim of this study was to characterize the...
The bacterial genus has been widely evaluated as promising bacteria to increase phosphorus (P) availability in soil. The aim of this study was to characterize the phosphate solubilizing (PS) activity of a strain and to evaluate the impact of its application in a semi-arid soil on phosphate availability and structure of the bacterial communities as a whole. An incubation experiment under close-to-natural soil environmental conditions was conducted for 15 days at 30 °C. High-throughput sequencing of the bacterial 16S rRNA gene was used to characterize and to compare the bacterial community structure of -inoculated soil with non-inoculated control. Furthermore, a qPCR-based method was developed for detection and quantification of the functional genes related to the expression of mineral phosphate solubilization (MPS) phenotype in . The results showed that in vitro solubilization of Ca(PO) by strain was very efficient (980 mg/L), and it was associated with a drop in pH due to the secretion of gluconic acid; these changes were concomitant with the detection of and genes. Moreover, inoculum application significantly increased the content of available P in semi-arid soil by 69%. Metagenomic analyses showed that treatment modified the overall edaphic bacterial community, significantly impacting its structure and composition. In particular, during inoculation the relative abundance of bacteria belonging to Firmicutes (mainly class) significantly increased, whereas the abundance of Actinobacteria together with Acidobacteria and Chloroflexi phyla decreased. Furthermore, genera known for their phosphate solubilizing activity, such as , , , and were exclusively detected in -treated soil. Pearson's correlation analysis revealed that changes in soil bacterial community composition were closely affected by soil characteristics, such as pH and available P. This study explores the effect of the inoculation of on the bacterial community structure of a semi-arid soil. The effectiveness in improving the phosphate availability and modification in soil bacterial community suggested that represent a promising environmental-friendly biofertilizer in arid and semi-arid ecosystems.
PubMed: 34442740
DOI: 10.3390/microorganisms9081661 -
PloS One 2019The Enterobacterial genus Pantoea contains both free-living and host-associating species, with considerable debate as to whether documented reports of human infections...
The Enterobacterial genus Pantoea contains both free-living and host-associating species, with considerable debate as to whether documented reports of human infections by members of this species group are accurate. MALDI-TOF-based identification methods are commonly used in clinical laboratories as a rapid means of identification, but its reliability for identification of Pantoea species is unclear. In this study, we carried out cpn60-based molecular typing of 54 clinical isolates that had been identified as Pantoea using MALDI-TOF and other clinical typing methods. We found that 24% had been misidentified, and were actually strains of Citrobacter, Enterobacter, Kosakonia, Klebsiella, Pseudocitrobacter, members of the newly described Erwinia gerundensis, and even several unclassified members of the Enterobacteriaceae. The 40 clinical strains that were confirmed to be Pantoea were identified as Pantoea agglomerans, Pantoea allii, Pantoea dispersa, Pantoea eucalypti, and Pantoea septica as well as the proposed species group, Pantoea latae. Some species groups considered largely environmental or plant-associated, such as P. allii and P. eucalypti were also among clinical specimens. Our results indicate that MALDI-TOF-based identification methods may misidentify strains of the Enterobacteriaceae as Pantoea.
Topics: Bacterial Typing Techniques; Diagnostic Errors; Enterobacteriaceae Infections; Humans; Pantoea; Phylogeny; Plants; Reproducibility of Results; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 31682625
DOI: 10.1371/journal.pone.0224731