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Plants (Basel, Switzerland) May 2023In this study, the biochemical, antioxidant properties, and antimicrobial activity of the epiphytic leafy liverwort (L.) Dumort were investigated. Due to the scarcity...
In this study, the biochemical, antioxidant properties, and antimicrobial activity of the epiphytic leafy liverwort (L.) Dumort were investigated. Due to the scarcity and difficulty in obtaining liverworts, research on their bioactivity is limited; thus, this study aimed to uncover the potential of . The antimicrobial activity was evaluated against various microorganisms, including food isolates, clinical isolates, multidrug-resistant strains, and standard strains, using the disk diffusion method and determining the minimum inhibitory concentration (MIC) values. This study represents the first antioxidant investigation on and an antimicrobial study using ethanol extract and the disk diffusion method. Notably, susceptibility was observed in ATCC 29212, FI, ATCC 7644, MDR, and ATCC 25923. The antioxidant capacity was assessed using the DPPH method, emphasizing the high scavenging performance. Gas chromatography-mass spectrometry (GC-MS) analysis identified the primary compounds as frullanolide (19.08%), 2,3-Dimethylanisole (15.21%), linoleic acid (11.11%), palmitic acid (9.83%), and valerenic acid (5.3%). The results demonstrated the significant antimicrobial activity of against the tested microorganisms and its potent antioxidant properties. These findings emphasize the potential of as a promising source of natural antimicrobial and antioxidant agents, underscoring the importance of further investigation into its bioactive compounds and elucidating the mechanisms of action in future studies.
PubMed: 37176934
DOI: 10.3390/plants12091877 -
Infection and Immunity Jun 2023Providencia rustigianii is potentially enteropathogenic in humans. Recently, we identified a strain carrying a part of the gene homologous to that of that produces an...
Providencia rustigianii is potentially enteropathogenic in humans. Recently, we identified a strain carrying a part of the gene homologous to that of that produces an exotoxin called cytolethal distending toxin (CDT), encoded by three subunit genes (, , and ). In this study, we analyzed the strain for possible presence of the entire gene cluster and its organization, location, and mobility, as well as expression of the toxin as a putative virulence factor of . Nucleotide sequence analysis revealed the presence of the three subunit genes in tandem, and over 94% homology to the corresponding genes carried by P. alcalifaciens both at nucleotide and amino acid sequence levels. The strain produced biologically active CDT, which caused distension of eukaryotic cell lines with characteristic tropism of CHO and Caco-2 cells but not of Vero cells. S1-nuclease digested pulsed-field gel electrophoresis followed by Southern hybridization analysis demonstrated that the genes in both and P. alcalifaciens strains are located on large plasmids (140 to 170 kb). Subsequently, conjugation assays using a genetically marked derivative of the strain showed that the plasmid carrying genes in the was transferable to gene-negative recipient strains of , Providencia rettgeri, and Escherichia coli. Our results demonstrated the presence of genes in for the first time, and further showed that the genes are located on a transferable plasmid, which can potentially spread to other bacterial species.
Topics: Animals; Chlorocebus aethiops; Humans; Providencia; Vero Cells; Caco-2 Cells; Escherichia coli
PubMed: 37158737
DOI: 10.1128/iai.00121-22 -
Biotechnology and Bioengineering Apr 20234-hydroxybenzoic acid (4-HBA) is an industrially important aromatic compound, and there is an urgent need to establish a bioprocess to produce this compound in a...
4-hydroxybenzoic acid (4-HBA) is an industrially important aromatic compound, and there is an urgent need to establish a bioprocess to produce this compound in a sustainable and environmentally friendly manner from renewable feedstocks such as cellulosic biomass. Here, we developed a bioprocess to directly produce 4-HBA from cellulose using a recombinant Pichia pastoris strain that displays heterologous cellulolytic enzymes on its cell surface via the glycosylphosphatidylinositol (GPI)-anchoring system. β-glucosidase (BGL) from Aspergillus aculeatus, endoglucanase (EG) from Trichoderma reesei, and cellobiohydrolase (CBH) from Talaromyces emersonii were co-displayed on the cell surface of P. pastoris using an appropriate GPI-anchoring domain for each enzyme. The cell-surface cellulase activity was further enhanced using P. pastoris SPI1 promoter- and secretion signal sequences. The resulting strains efficiently hydrolyzed phosphoric acid swollen cellulose (PASC) to glucose. Then, we expressed a highly 4-HBA-resistant chorismate pyruvate-lyase (UbiC) from Providencia rustigianii in the cellulase-displaying strain. This strain produced 975 mg/L of 4-HBA from PASC, which corresponding to 36.8% of the theoretical maximum yield, after 96 h of batch fermentation without the addition of commercial cellulase. This 4-HBA yield was over two times higher than that obtained from glucose (12.3% of the theoretical maximum yield). To our knowledge, this is the first report on the direct production of an aromatic compound from cellulose using cellulase-displaying yeast.
Topics: Cellulase; Cellulose; Saccharomyces cerevisiae; Glucose
PubMed: 36575132
DOI: 10.1002/bit.28321 -
Chemistry (Weinheim An Der Bergstrasse,... May 2020A general and efficient strategy for synthesis of tri-, hexa- and heptasaccharidic substructures of the lipopolysaccharide of Providencia rustigianii O34 is described....
A general and efficient strategy for synthesis of tri-, hexa- and heptasaccharidic substructures of the lipopolysaccharide of Providencia rustigianii O34 is described. For the heptasaccharide seven different building blocks were employed. Special features of the structures are an α-linked galactosamine and the two embedded α-fucose units, which are either branched at positions-3 and -4 or further linked at their 2-position. Convergent strategies focused on [4+3], [3+4], and [4+2+1] couplings. Whereas the [4+3] and [3+4] coupling strategies failed the [4+2+1] strategy was successful. As monosaccharidic building blocks trichloroacetimidates and phosphates were employed. Global deprotection of the fully protected structures was achieved by Birch reaction.
PubMed: 32092205
DOI: 10.1002/chem.202000496 -
Pathogens and Disease Dec 2018This study was aimed to develop a multiplex PCR (m-PCR) for the detection of Escherichia coli attaching and effacing (eae), Shiga toxin (stx) and cytolethal distending...
This study was aimed to develop a multiplex PCR (m-PCR) for the detection of Escherichia coli attaching and effacing (eae), Shiga toxin (stx) and cytolethal distending toxin (cdt) genes encoding important virulence factors of diarrheagenic E. coli such as EPEC, STEC, and Escherichia albertii. For this purpose, the m-PCR was designed to detect eae, all the subtypes of stx (stx1, stx2a-g except stx2f) and cdt (I-V) genes. The m-PCR was validated with 58 and 55 target gene-positive and negative strains of different sources, respectively. Sensitivity and specificity of the m-PCR were 100%. The m-PCR could also detect the eae, stx and cdt genes in bacteria spiked into stool specimens with or without enrichment culture. Clinical specimens collected from children with diarrhea were tested by the m-PCR, and 27 eae and 32 cdt genes were detected. Among them, three cdt-II and one untypable cdt gene-positive bacteria were isolated and identified as E. albertii and Providencia rustigianii, respectively. This is the first report demonstrating the presence of cdtB gene in P. rustigianii. These results indicate that the m-PCR is useful for surveillance of eae, stx and cdt gene-positive bacteria, not only EPEC, STEC and E. albertii but also P. rustigianii.
Topics: Adhesins, Bacterial; Bacterial Toxins; Child; Child, Preschool; Diarrhea; Enterobacteriaceae Infections; Escherichia coli; Escherichia coli Proteins; Female; Humans; Infant; Male; Multiplex Polymerase Chain Reaction; Providencia; Sensitivity and Specificity; Shiga Toxin
PubMed: 30657893
DOI: 10.1093/femspd/ftz002 -
Journal of Food Science and Technology Dec 2018Ammonia-producing bacteria were isolated and identified from five commercial fermented skates (A1, A2, A3, A4, and A5). In addition, the pH, ammonia nitrogen, total...
Ammonia-producing bacteria were isolated and identified from five commercial fermented skates (A1, A2, A3, A4, and A5). In addition, the pH, ammonia nitrogen, total volatile nitrogen (TVBN), trimethylamine nitrogen (TMAN), and amino nitrogen contents of skate samples were also determined. A total of 88 strains of ammonia-producing bacteria was isolated and seven hyper-ammonia-producing bacteria isolates (A2-2, A2-3, A2-12, A2-18, A2-20, A3-6 and A3-14) were selected based on ammonia nitrogen producing ability. Those isolates were identified as (three strains), (three strains), and . The pH and ammonia nitrogen content in skate samples were ranged from 8.63 to 9.03, and 4.86 to 7.31 g/kg, respectively. No significant difference of pH values was observed in skate samples A2, A3, A4 and A5. While, skate samples A3, A4 and A5 showed similar level of TVBN and TMAN content. Skate sample A2 showed the highest amino nitrogen content among all samples, which indicated the highest degree of protein degradation of skate muscle during fermentation. Bivariate cluster analysis showed that skate samples A3, A4, and A5 clustered together at a relatively high level, implying a similar microbial environment during fermentation. The cluster analysis allowed different commercial fermented skates to be clearly differentiated based on the characteristics determined in this study. This study can provide important information for investigating the mechanisms underlying ammonia flavor formation in skate muscle during fermentation.
PubMed: 30483004
DOI: 10.1007/s13197-018-3447-9 -
Applied and Environmental Microbiology Mar 2018was metabolically engineered to produce 4-hydroxybenzoic acid (4-HBA), a valuable aromatic compound used as a raw material for the production of liquid crystal polymers...
was metabolically engineered to produce 4-hydroxybenzoic acid (4-HBA), a valuable aromatic compound used as a raw material for the production of liquid crystal polymers and paraben. was found to have a higher tolerance to 4-HBA toxicity than previously reported hosts used for the production of genetically engineered 4-HBA. To obtain higher titers of 4-HBA, we employed a stepwise overexpression of all seven target genes in the shikimate pathway in Specifically, multiple chromosomal integrations of a mutated gene from , encoding a 3-deoxy-d-arabinoheptulosonic acid 7-phosphate (DAHP) synthase, and wild-type from , encoding chorismate synthase, shikimate kinase, and 3-dehydroquinate synthase, were effective in increasing product titers. The last step of the 4-HBA biosynthesis pathway was recreated in by expressing a highly 4-HBA-resistant chorismate pyruvate-lyase (UbiC) from the intestinal bacterium To enhance the yield of 4-HBA, we reduced the formation of by-products, such as 1,3-dihydroxyacetone and pyruvate, by deleting , a gene coding for a haloacid dehalogenase superfamily phosphatase, and , a gene coding for a pyruvate kinase, from the bacterial chromosome. The maximum concentration of 4-HBA produced by the resultant strain was 36.6 g/liter, with a yield of 41% (mol/mol) glucose after incubation for 24 h in minimal medium in an aerobic growth-arrested bioprocess using a jar fermentor. To our knowledge, this is the highest concentration of 4-HBA produced by a metabolically engineered microorganism ever reported. Since aromatic compound 4-HBA has been chemically produced from petroleum-derived phenol for a long time, eco-friendly bioproduction of 4-HBA from biomass resources is desired in order to address environmental issues. In microbial chemical production, product toxicity often causes problems, but we confirmed that wild-type has high tolerance to the target 4-HBA. A growth-arrested bioprocess using this microorganism has been successfully used for the production of various compounds, such as biofuels, organic acids, and amino acids. However, no production method has been applied for aromatic compounds to date. In this study, we screened for a novel final reaction enzyme possessing characteristics superior to those in previously employed microbial 4-HBA production. We demonstrated that the use of the highly 4-HBA-resistant UbiC from the intestinal bacterium is very effective in increasing 4-HBA production.
Topics: Aerobiosis; Corynebacterium glutamicum; Glucose; Metabolic Engineering; Parabens
PubMed: 29305513
DOI: 10.1128/AEM.02587-17 -
BMC Research Notes Oct 2017Providencia are gram negative motile rods and is a member of the Enterobacteriaceae family. It consists of five species, namely Providencia alcalifaciens, Providencia...
BACKGROUND
Providencia are gram negative motile rods and is a member of the Enterobacteriaceae family. It consists of five species, namely Providencia alcalifaciens, Providencia rustigianii, Providencia stuartii, Providencia rettgeri and Providencia heimbachae. These are opportunistic pathogens and leads to infections in immunocompromised host. Providencia rettgeri has been associated with the nosocomial infections of the urinary tract and infections of wounds, burns and blood. Providencia rettgeri is very rare cause of neonatal sepsis and we report first case of neonatal late onset sepsis secondary to it.
CASE PRESENTATION
A term male infant presented on day 4 of post-natal life with the complaint of decreased appetite, fast respiration and lethargy. The clinical examination showed features of sepsis and shock with chest radiogram showing pneumonia. The infant was started on invasive ventilation, intravenous fluids, antibiotic and inotropes. The blood culture was suggestive of multi-drug resistant P. rettgeri. The antibiotics were changed according to organism antibiotic susceptibility pattern and infant gradually improved and was discharged successfully.
CONCLUSION
Providencia rettgeri is a very rare organism to cause neonatal sepsis. The management involves early diagnosis, treatment with appropriate antibiotics and finding the source of infection.
Topics: Drug Resistance, Multiple, Bacterial; Humans; Infant, Newborn; Male; Neonatal Sepsis; Providencia
PubMed: 29084590
DOI: 10.1186/s13104-017-2866-4 -
Microbiology (Reading, England) Apr 2012Enterobacteria of the genus Providencia are opportunistic human pathogens associated with urinary tract and wound infections, as well as enteric diseases. The...
Enterobacteria of the genus Providencia are opportunistic human pathogens associated with urinary tract and wound infections, as well as enteric diseases. The lipopolysaccharide (LPS) O antigen confers major antigenic variability upon the cell surface and is used for serotyping of Gram-negative bacteria. Recently, Providencia O antigen structures have been extensively studied, but no data on the location and organization of the O antigen gene cluster have been reported. In this study, the four Providencia genome sequences available were analysed, and the putative O antigen gene cluster was identified in the polymorphic locus between the cpxA and yibK genes. This finding provided the necessary information for designing primers, and cloning and sequencing the O antigen gene clusters from five more Providencia alcalifaciens strains. The gene functions predicted in silico were in agreement with the known O antigen structures; furthermore, annotation of the genes involved in the three-step synthesis of GDP-colitose (gmd, colD and colC) was supported by cloning and biochemical characterization of the corresponding enzymes. In one strain (P. alcalifaciens O39), no polysaccharide product of the gene cluster in the cpxA-yibK locus was found, and hence genes for synthesis of the existing O antigen are located elsewhere in the genome. In addition to the putative O antigen synthesis genes, homologues of wza, wzb, wzc and (in three strains) wzi, required for the surface expression of capsular polysaccharides, were found upstream of yibK in all species except Providencia rustigianii, suggesting that the LPS of these species may be attributed to the so-called K LPS (K(LPS)). The data obtained open a way for development of a PCR-based typing method for identification of Providencia isolates.
Topics: Cloning, Molecular; DNA, Bacterial; Genetic Loci; Guanosine Diphosphate Sugars; Molecular Sequence Data; Multigene Family; O Antigens; Providencia; Sequence Analysis, DNA
PubMed: 22282517
DOI: 10.1099/mic.0.055210-0 -
Carbohydrate Research Feb 2012An acidic polysaccharide was isolated from Providencia rustigianii O11 by the phenol-water extraction. The polysaccharide was cleaved by solvolysis with triflic acid to...
An acidic polysaccharide was isolated from Providencia rustigianii O11 by the phenol-water extraction. The polysaccharide was cleaved by solvolysis with triflic acid to yield disaccharides with uronic acid derivatives at the non-reducing end. The polysaccharide and the disaccharides were studied by chemical analyses, high-resolution ESI MS, and 2D (1)H and (13)C NMR spectroscopy, and the following structure of the tetrasaccharide repeating unit of the polysaccharide was established: where GalNAcA stands for 2-acetamido-2-deoxygalacturonic acid, GalNAcA6GluAla for N-(2-acetamido-2-deoxygalacturonoyl)-l-glutam-1-yl-l-alanine, QuiNAc4NAcyl for 2-acetamido-4-[(S)-3-hydroxybutanoylamino]-2,4,6-trideoxyglucose (∼75%) or 2,4-diacetamido-2,4,6-trideoxyglucose (∼25%); the d configuration of GalNA and QuiN4N was ascribed tentatively. To the best of our knowledge, this is for the first time that an amide of uronic acid with a dipeptide is found in bacterial polysaccharides.
Topics: Amides; Carbohydrate Conformation; Dipeptides; Polysaccharides, Bacterial; Providencia
PubMed: 22230711
DOI: 10.1016/j.carres.2011.12.012