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Pharmaceutics Oct 2021The present study describes the isolation and characterization of novel bacterial species sp. nov., applied for the green synthesis of AgNPs, and investigates its...
Characterization and Genome Analysis of sp. nov., Applied for the Green Synthesis of Silver Nanoparticles and Their Antibacterial Efficacy against Drug-Resistant Human Pathogens.
The present study describes the isolation and characterization of novel bacterial species sp. nov., applied for the green synthesis of AgNPs, and investigates its antibacterial efficacy against drug-resistant pathogenic Typhimurium and . Novel strain MAHUQ-56 is Gram-positive, aerobic, non-motile, and rod-shaped. Colonies were spherical and milky white. The strain showed positive activity for catalase and nitrate reductase, and the hydrolysis of starch, L-tyrosine, casein, and Tween 20. On the basis of the 16S rRNA gene sequence, strain MAHUQ-56 belongs to the genus and is most closely related to P3B162 (98.6%). MAHUQ-56 has a genome 4,566,112 bp long (26 contigs) with 4125 protein-coding genes, 51 tRNA and 6 rRNA genes. The culture supernatant of MAHUQ-56 was used for the easy and green synthesis of AgNPs. Synthesized AgNPs were characterized by UV-vis spectroscopy, FE-TEM, XRD, DLS, and FT-IR. Synthesized AgNPs were spherical and 12-50 nm in size. FT-IR analysis revealed various biomolecules that may be involved in the synthesis process. Synthesized AgNPs showed strong antibacterial activity against multidrug-resistant pathogenic and . MIC values of the synthesized AgNPs against and were 6.2 and 3.1 ug/mL, respectively. The MBC of synthesized AgNPs for both pathogens was 12.5 ug/mL. FE-SEM analysis revealed the morphological and structural alterations, and damage of pathogens treated by AgNPs. These changes might disturb normal cellular functions, which ultimately leads to the death of cells.
PubMed: 34683984
DOI: 10.3390/pharmaceutics13101691 -
World Journal of Microbiology &... Jul 2022Leucaena leucocephala growing in the tropics and subtropics serves as potential forage for livestock because its foliage is rich in protein, fiber, and minerals....
Leucaena leucocephala growing in the tropics and subtropics serves as potential forage for livestock because its foliage is rich in protein, fiber, and minerals. However, its use for livestock feed has been hindered by toxic nonprotein amino acid mimosine. Therefore, it is necessary to develop a method to reduce or eliminate mimosine from foliage. A previous study found that the fermentation of L. leucocephala foliage reduced the mimosine content and prompted the authors to isolate potent mimosine degrading microorganisms and characterize the mimosinase for the complete elimination of mimosine in the L. leucocephala foliage. The soil screening of the L. leucocephala tree surroundings led to the isolation of Arthrobacter sp. Ryudai-S1, which can degrade and assimilate mimosine as a nitrogen and carbon source. Mimosinase in this strain was found to be thermostable and showed strong activity. Docking model's inspection and the interaction energy calculation between mimosine-pyridoxal-5'-phosphate (PLP) complex and the active site of this enzyme identified 11 important amino acid residues that stabilized the binding. Of these amino acid residues, mutation experiment suggested that Tyr-263' and Phe-34 stabilizes the substrate binding and play a critical role in guiding the substrate to proper positions to accomplish high catalytic efficacy and selectivity. These observations suggest that Arthrobacter sp. Ryudai-S1 could be potentially useful for the development of L. leucocephala feed with reduced mimosine content.
Topics: Arthrobacter; Catalytic Domain; Fabaceae; Hydrolases; Mimosine; Pyridoxal Phosphate
PubMed: 35908235
DOI: 10.1007/s11274-022-03344-y -
Antioxidants (Basel, Switzerland) Jul 2022The genus is a source of many natural products that are critical in the development of new medicines. Here, we isolated a novel carotenoid from sp. QL17 and...
The genus is a source of many natural products that are critical in the development of new medicines. Here, we isolated a novel carotenoid from sp. QL17 and characterized its properties. The carotenoid was extracted with methanol, and purified by column chromatography and semi-preparative HPLC. Based on micrOTOF-Q and NMR analyses, the pigment was chemically characterized as 2,2'-((((1E,3E,5E,7E,9E,11E,13E,15E,17E,19E)-3,7,14,18-tetramethylicosa-1,3,5,7,9,11,13,15,17,19-decaene-1,20-diyl)bis(2,2,4-trimethylcyclohex-3-ene-3,1-diyl)) bis(ethan-2-yl-1-ylidene))bi(propane-1,3-diol), and named arthroxanthin. The biological activities of arthroxanthin were evaluated with DPPH, ABTS and MTT assays. Arthroxanthin exhibited excellent radical scavenging properties, as shown for 2, 20-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-n-(3,2-ethyl-benzothiazole-6-sulfonic acid) ammonium salt (ABTS), respectively, with IC50s of 69.8 and 21.5 µg/mL. It also showed moderate anticancer activities against HepG2, Hela, MDAB-231, SW480, and MKN-45 with IC50 values of 107.6, 150.4, 143.4, 195.9, and 145.5 μg/mL, respectively. Therefore, arthroxanthin derived from sp. QL17 may be a potent antioxidant and anticancer agent for food and pharmaceutical use.
PubMed: 36009212
DOI: 10.3390/antiox11081493 -
Microbiology Resource Announcements Nov 2022We report the genome sequence of bacteriophage NathanVaag, an actinobacteriophage isolated from soil in El Paso, Texas, that infects sp. strain ATCC 21022. The...
We report the genome sequence of bacteriophage NathanVaag, an actinobacteriophage isolated from soil in El Paso, Texas, that infects sp. strain ATCC 21022. The 49,645-bp genome contains 73 predicted protein-coding genes. Based on gene content similarity to phages in the Actinobacteriophage Database, NathanVaag is assigned to phage cluster AO1.
PubMed: 36250873
DOI: 10.1128/mra.00940-22 -
Journal of Biotechnology Jan 2021Small molecules inhibitors of neuraminidases (NAs) are ones of the most prospective molecules proposed for the treatment of influenza viruses. The determination of their... (Review)
Review
Small molecules inhibitors of neuraminidases (NAs) are ones of the most prospective molecules proposed for the treatment of influenza viruses. The determination of their inhibition activity in vitro is an important step during the development of antiviral drugs. However, the analytical methods typically used for the evaluation of NA activity and inhibition (fluorescence-based assays using MUNANA substrate or thiobarbituric acid assay, TBA) may suffer from interferences caused by tested inhibitors as signal quenching or self-fluorescence, moreover in TBA are used toxic and carcinogenic reagents. The determination of the NA activity can be effectively performed by alternative methods based on lectin - glycan recognition, usually as enzyme-linked lectin assay (ELLA). We have adapted the ELLA assay to a lectin-based assay in a microplate format with fluorescence detection for determination of NA inhibitory activity. We optimized our protocol and the developed method was tested using four different small molecule NA inhibitors or potential NA inhibitors (DANA, zanamivir, quercetin and α-mangostin) with three bacterial NAs (from Clostridium perfringens, Vibrio cholerae and Arthrobacter ureafaciens), and the IC values for NA inhibitors were determined. The inhibition effect of DANA was observed for all 3 tested NAs (IC = 10.1 μM for V. cholerae, 13.4 μM for C. perfringens and 402.9 μM for A. ureafaciens, respectively) and of Zanamivir only for NA from V. cholerae (IC = 101.9 μM). For both quercetin and α-mangostin, no inhibition effect to the tested NAs was observed. The main advantages of herein described method are good sensitivity due to fluorescent signal detection, the absence of the interference caused by fluorescent signal quenching by tested inhibitors, the use of natural substrates (glycoproteins) and the avoiding the use of toxic reagents.
Topics: Antiviral Agents; Enzyme Inhibitors; Lectins; Micrococcaceae; Neuraminidase; Prospective Studies; Zanamivir
PubMed: 33220341
DOI: 10.1016/j.jbiotec.2020.11.016 -
Frontiers in Cellular and Infection... 2022Bile reflux can cause inflammation, gastric mucosa atrophy, and diseases such as stomach cancer. Alkaline bile flowing back into the stomach affects the intragastric...
BACKGROUND
Bile reflux can cause inflammation, gastric mucosa atrophy, and diseases such as stomach cancer. Alkaline bile flowing back into the stomach affects the intragastric environment and can alter the gastric bacterial community. We sought to identify the characteristics of the stomach mucosal microbiota in patients with bile reflux.
METHODS
Gastric mucosal samples were collected from 52 and 40 chronic gastritis patients with and without bile reflux, respectively. The bacterial profile was determined using 16S rRNA gene analysis.
RESULTS
In the absence of H. pylori infection, the richness (based on the Sobs and Chao1 indices; P <0.05) and diversity (based on Shannon indices; P <0.05) of gastric mucosa microbiota were higher in patients with bile reflux patients than in those without. There was a marked difference in the microbiota structure between patients with and without bile reflux (ANOSIM, R=0.058, P=0.011). While the genera, , , , , , , and were enriched in patients with bile reflux, the genera, , , and , were enriched in those without bile reflux.
CONCLUSION
Our results demonstrate that bile reflux significantly alters the composition of the gastric microbiota.
Topics: Bile Reflux; Gastric Mucosa; Gastritis; Helicobacter Infections; Helicobacter pylori; Humans; Microbiota; RNA, Ribosomal, 16S
PubMed: 36159635
DOI: 10.3389/fcimb.2022.940687 -
Frontiers in Bioengineering and... 2021Dextran has aroused increasingly more attention as the primary pollutant in sucrose production and storage. Although enzymatic hydrolysis is more efficient and...
Dextran has aroused increasingly more attention as the primary pollutant in sucrose production and storage. Although enzymatic hydrolysis is more efficient and environmentally friendly than physical methods, the utilization of dextranase in the sugar industry is restricted by the mismatch of reaction conditions and heterogeneity of hydrolysis products. In this research, a dextranase from G6-4B was purified and characterized. Through anion exchange chromatography, dextranase was successfully purified up to 32.25-fold with a specific activity of 288.62 U/mg protein and a Mw of 71.12 kDa. The optimum reaction conditions were 55°C and pH 7.5, and it remained relatively stable in the range of pH 7.0-9.0 and below 60°C, while significantly inhibited by metal ions, such as Ni, Cu, Zn, Fe, and Co. Noteworthily, a distinction of previous studies was that the hydrolysates of dextran were basically isomalto-triose (more than 73%) without glucose, and the type of hydrolysates tended to be relatively stable in 30 min; dextranase activity showed a great influence on hydrolysate. In conclusion, given the superior thermal stability and simplicity of hydrolysates, the dextranase in this study presented great potential in the sugar industry to remove dextran and obtain isomalto-triose.
PubMed: 35223821
DOI: 10.3389/fbioe.2021.813079 -
PloS One 2021Despite the formation of biofilms on catheters for extracorporeal membrane oxygenation (ECMO), some patients do not show bacteremia. To elucidate the specific linkage...
Despite the formation of biofilms on catheters for extracorporeal membrane oxygenation (ECMO), some patients do not show bacteremia. To elucidate the specific linkage between biofilms and bacteremia in patients with ECMO, an improved understanding of the microbial community within catheter biofilms is necessary. Hence, we aimed to evaluate the biofilm microbiome of ECMO catheters from adults with (n = 6) and without (n = 15) bacteremia. The microbiomes of the catheter biofilms were evaluated by profiling the V3 and V4 regions of bacterial 16s rRNA genes using the Illumina MiSeq sequencing platform. In total, 2,548,172 reads, with an average of 121,341 reads per sample, were generated. Although alpha diversity was slightly higher in the non-bacteremic group, the difference was not statistically significant. In addition, there was no difference in beta diversity between the two groups. We found 367 different genera, of which 8 were present in all samples regardless of group; Limnohabitans, Flavobacterium, Delftia, Massilia, Bacillus, Candidatus, Xiphinematobacter, and CL0-1 showed an abundance of more than 1% in the sample. In particular, Arthrobacter, SMB53, Neisseria, Ortrobactrum, Candidatus Rhabdochlamydia, Deefgae, Dyella, Paracoccus, and Pedobacter were highly abundant in the bacteremic group. Network analysis indicated that the microbiome of the bacteremic group was more complex than that of the non-bacteremic group. Flavobacterium and CL0.1, which were abundant in the bacteremic group, were considered important genera because they connected different subnetworks. Biofilm characteristics in ECMO catheters varied according to the presence or absence of bacteremia. There were no significant differences in diversity between the two groups, but there were significant differences in the community composition of the biofilms. The biofilm-associated community was dynamic, with the bacteremic group showing very complex network connections within the microbiome.
Topics: Arthrobacter; Bacteremia; Bacteria; Biofilms; Catheter-Related Infections; Extracorporeal Membrane Oxygenation; Female; Humans; Male; Microbiota; Middle Aged; Neisseria; RNA, Ribosomal, 16S; Retrospective Studies
PubMed: 34529734
DOI: 10.1371/journal.pone.0257449 -
Environmental Science and Pollution... Dec 2020The effect of fungicides, commonly used in vine cultures, on the health of terrestrial and aquatic ecosystems has been poorly studied. The objective of this study was to...
The effect of fungicides, commonly used in vine cultures, on the health of terrestrial and aquatic ecosystems has been poorly studied. The objective of this study was to evaluate the toxicity of three viticulture fungicides (myclobutanil, cymoxanil, and azoxystrobin) on non-target organisms, the bacteria Rhodopirellula rubra, Escherichia coli, Pseudomonas putida, and Arthrobacter sp., the microalgae Raphidocelis subcapitata, and the macrophyte Lemna minor. Fungicide toxicity was performed in acute cell viability assay for bacteria; 72-h and 7-day growth inhibition tests for R. subcapitata and L. minor, respectively. Contents of photosynthetic pigments and lipid peroxidation in L. minor were evaluated. Arthrobacter sp. and P. putida showed resistance to these fungicides. Even though azoxystrobin affected R. rubra and E. coli cell viability, this effect was due to the solvent used, acetone. Cell viability decrease was obtained for R. rubra exposed to cymoxanil and E. coli exposed to myclobutanil (30 min of exposure at 10 mg/L and 240 min of exposure at 46 mg/L, respectively). R. subcapitata showed about 10-fold higher sensitivity to azoxystrobin (EC = 0.25 mg/L) and cymoxanil (EC = 0.36 mg/L) than L. minor to azoxystrobin and myclobutanil (EC = 1.53 mg/L and EC = 1.89 mg/L, respectively). No lipid peroxidation was observed in L. minor after fungicide exposure, while changes of total chlorophyll were induced by azoxystrobin and myclobutanil. Our results showed that non-target aquatic organisms of different trophic levels are affected by fungicides used in viticulture.
Topics: Ecosystem; Ecotoxicology; Escherichia coli; Fungicides, Industrial; Planctomycetales
PubMed: 32748361
DOI: 10.1007/s11356-020-10245-w -
Journal of Applied Microbiology Nov 2022The rhizosphere is the region around the plant roots where maximum microbial activities occur. In the rhizosphere, microorganisms' beneficial and harmful activities... (Review)
Review
The rhizosphere is the region around the plant roots where maximum microbial activities occur. In the rhizosphere, microorganisms' beneficial and harmful activities affect plant growth and development. The mutualistic rhizospheric bacteria which improve plant growth and health are known as plant growth-promoting rhizobacteria (PGPR). They are very important due to their ability to help the plant in diverse ways. PGPR such as Pseudomonas, Bacillus, Azospirillum, Azotobacter, Arthrobacter, Achromobacter, Micrococcus, Enterobacter, Rhizobium, Agrobacterium, Pantoea and Serratia are now very well known. Rhizomicrobiome plays critical roles in nutrient acquisition and assimilation, improved soil texture, secreting and modulating extracellular molecules such as hormones, secondary metabolites, antibiotics and various signal compounds, all leading to the enhancement of plant growth and development. The microbes and compounds they secrete constitute valuable biostimulants and play pivotal roles in modulating plant stress responses. In this review, we highlight the rhizobacteria diversity and cutting-edge findings focusing on the role of a PGPR in plant growth and development. We also discussed the role of PGPR in resisting the adverse effects arising from various abiotic (drought, salinity, heat, heavy metals) stresses.
Topics: Plant Development; Rhizosphere; Stress, Physiological; Plant Roots; Soil Microbiology; Soil; Metals, Heavy; Pantoea; Anti-Bacterial Agents; Hormones
PubMed: 36017561
DOI: 10.1111/jam.15796