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International Microbiology : the... May 2021High-altitude cold habitats of the Karakoram are rarely explored for their bacterial community characterization and metabolite productions. In the present study,...
High-altitude cold habitats of the Karakoram are rarely explored for their bacterial community characterization and metabolite productions. In the present study, bacterial communities in ice, water, and sediments of Batura Glacier were investigated using culture-dependent and culture-independent methods. Twenty-seven cold-adapted bacterial strains (mostly psychrotrophic) were isolated using R2A, Tryptic Soy Agar (TSA), and Luria-Bertani (LB) media, at 4 °C and 15 °C. Most of the isolates exhibited growth at a wide range of temperature (4-35 °C), pH (5-12), and salinity (1-6%). Among the bacterial isolates, 52% were identified as Gram-positive and the remaining 48% represented as Gram-negative. The results of phylogenetic analysis indicated that all the culturable bacteria belonged to 3 major phylogenetic groups, i.e., Actinobacteria (48%), Bacteroidetes (26%), and Proteobacteria (22%), while Flavobacterium (26%), Arthrobacter (22%), and Pseudomonas (19%) were represented as the dominant genera. Similarly, Illumina amplicon sequencing of 16S rRNA genes after PCR amplification of DNA from the whole community revealed dominance of the same phylogenetic groups, Proteobacteria, Actinobacteria, and Bacteroidetes, while Arthrobacter, Mycoplana, Ochrobactrum, Kaistobacter, Janthinobacterium, and Flavobacterium were found as the dominant genera. Among the culturable isolates, 70% demonstrated activity for cellulases, 48% lipases, 41% proteases, 41% DNases, and only 7% for amylases. Most of the glacial isolates demonstrated antimicrobial activity against other microorganisms including the multiple-drug-resistant strains of Candida albicans, Klebsiella pneumoniae, Acinetobacter sp., and Bacillus sp. 67% of Gram-negative while 46% of Gram-positive glacial bacteria were resistant to trimethoprim/sulfamethoxazole. Resistance against methicillin and vancomycin among the Gram-positive isolates was 23% and 15%, respectively, while 11% of the Gram-negative isolates exhibited resistance against both colistin sulfate and nalidixic acid.
Topics: Anti-Bacterial Agents; Bacteria; DNA, Bacterial; DNA, Ribosomal; Ice Cover; Microbiota; Pakistan; Phylogeny; RNA, Ribosomal, 16S
PubMed: 33404934
DOI: 10.1007/s10123-020-00153-x -
Plants (Basel, Switzerland) Feb 2024The application of biostimulants has been proven to be an advantageous tool and an appropriate form of management towards the effective use of natural resources, food... (Review)
Review
The application of biostimulants has been proven to be an advantageous tool and an appropriate form of management towards the effective use of natural resources, food security, and the beneficial effects on plant growth and yield. Plant-growth-promoting rhizobacteria (PGPR) are microbes connected with plant roots that can increase plant growth by different methods such as producing plant hormones and molecules to improve plant growth or providing increased mineral nutrition. They can colonize all ecological niches of roots to all stages of crop development, and they can affect plant growth and development directly by modulating plant hormone levels and enhancing nutrient acquisition such as of potassium, phosphorus, nitrogen, and essential minerals, or indirectly via reducing the inhibitory impacts of different pathogens in the forms of biocontrol parameters. Many plant-associated species such as , , , , , and can increase plant growth by improving plant disease resistance, synthesizing growth-stimulating plant hormones, and suppressing pathogenic microorganisms. The application of biostimulants is both an environmentally friendly practice and a promising method that can enhance the sustainability of horticultural and agricultural production systems as well as promote the quantity and quality of foods. They can also reduce the global dependence on hazardous agricultural chemicals. Science Direct, Google Scholar, Springer Link, CAB Direct, Scopus, Springer Link, Taylor and Francis, Web of Science, and Wiley Online Library were checked, and the search was conducted on all manuscript sections in accordance with the terms , , , , , , , , Biostimulants, Plant growth promoting rhizobactera, and . The aim of this manuscript is to survey the effects of plant-growth-promoting rhizobacteria by presenting case studies and successful paradigms in various agricultural and horticultural crops.
PubMed: 38475460
DOI: 10.3390/plants13050613 -
Frontiers in Plant Science 2021The rhizosheath is a critical interface supporting the exchange of resources between plants and their associated environment of soil. Favorable microenvironment of...
The rhizosheath is a critical interface supporting the exchange of resources between plants and their associated environment of soil. Favorable microenvironment of rhizosphere soil provides the rhizosheath formed and then promotes desert plant survival. However, it remains unclear how rhizosheath benefits the colonization of pioneer plants in alpine desert under changing environment. In this study, we investigated the effect of different soil moisture and sterilization treatments (three moisture levels and unsterilized or sterilized soil) on rhizosheath forming process of (), a sand-inhabiting and drought-resistant pioneer plant of the Tibetan Plateau desert. The results showed that in both unsterilized and sterilized soil, increasing soil moisture first increased and then decreased rhizosheath weight, with the highest value is 25%. During rhizosheath formation, developing rhizosheaths were selectively enriched in the bacterial genera and . These suggest the existence of a highly specialized signal recognition system during rhizosheath formation that involves the accumulation of bacteria. These bacterial species exhibited different roles in the process of rhizosheath formation and is an advantageous strategy for .
PubMed: 35154178
DOI: 10.3389/fpls.2021.785971 -
International Journal of Infectious... Nov 2023We report the isolation of a rare Gram-positive coccobacillary bacterium from synovial fluids of a patient with periprosthetic joint infection on three occasions over an...
We report the isolation of a rare Gram-positive coccobacillary bacterium from synovial fluids of a patient with periprosthetic joint infection on three occasions over an 8-month period. As routine microbiological methods were not able to identify the isolate definitely, sequence analyses of the bacterial 16S ribosomal RNA gene and whole genome were performed. Analysis of the bacterial 16S ribosomal RNA gene showed the highest similarity (98.1%) with that of Falsarthrobacter (previously known as Arthrobacter) nasiphocae, which was first isolated from the nasal cavities of common seals (Phoca vitulina). The genome size of the strain (designated as UM1) is 2.4 Mb. With a high G+C content (70.4 mol%), strain UM1 is phylogenetically most closely related to F. nasiphocae based on whole genome analysis. Strain UM1 was susceptible to vancomycin, linezolid, trimethoprim-sulfamethoxazole, doxycycline, and intermediate to penicillin and ciprofloxacin. Ceftriaxone resistance was noted. The patient who was also on hemodialysis for his end stage kidney disease died approximately 3 weeks following implant removal and fusion with an external fixator. This study describes the first isolation of F. nasiphocae from human clinical samples. The use of emerging technologies has supported more definitive etiological diagnosis associated with rarely encountered organisms in periprosthetic joint infection.
Topics: Humans; Prosthesis-Related Infections; Micrococcaceae; Bacteria; Arthritis, Infectious; Gram-Positive Bacteria
PubMed: 37660726
DOI: 10.1016/j.ijid.2023.08.025 -
Journal of Applied Microbiology Sep 2019Study is focused on the influence of cadmium addition to growth media on production yield, their size and molecular mass of exopolysaccharides (EPS) synthesized by three...
AIM
Study is focused on the influence of cadmium addition to growth media on production yield, their size and molecular mass of exopolysaccharides (EPS) synthesized by three rhizosphere bacteria strains. Inhibition of bacterial growth by increasing concentrations of Cd was also analysed.
METHODS AND RESULTS
The highest impact of Cd was noticed on the growth of Arthrobacter sp. and Rhizobium metallidurans. Chryseobacterium sp. and Arthrobacter sp. produced significantly lower when compared to R. metallidurans amounts of EPS under the influence of Cd . In all bacterial strains both size and molecular mass decreased after addition of Cd to growth media. It causes a change in EPS conformation to more planar, which minimizes the volume of liquid in the interglobular space next to the bacterial wall. Results confirmed strong effect of Cd on the structure and synthesis of bacterial EPS what can be a key factor in the interactions between rhizosphere bacteria and host plants in heavy metal polluted soils.
CONCLUSION
This work proves that due to the presence of cadmium ions, the size and conformation of EPS produced by selected bacterial strains is changed to minimize their impact on cell. We suggest that shifting in EPS conformation from bigger globular particles to the smaller planar ones could be one of the probable mechanisms of Cd resistance in metallotolerant bacteria, and finally explain increased efficiency of heavy metal phytoextraction by EPS-producing plant growth-promoting micro-organisms.
SIGNIFICANCE AND IMPACT OF THE STUDY
One of the most promising remediation technique for Cd-contaminated areas is the phytoremediation in which rhizosphere bacteria play an important role by protecting plants' roots from toxic condition thus enhancing efficiency of intake. EPS secretion by bacteria is one of the most common mechanisms to protect the cell from impact of unpleasant environmental conditions, for example, toxicity of heavy metals like Cd.
Topics: Arthrobacter; Bacteria; Biodegradation, Environmental; Cadmium; Flavobacteriaceae; Polysaccharides, Bacterial; Rhizobium; Rhizosphere; Soil Pollutants
PubMed: 31211899
DOI: 10.1111/jam.14354 -
Environmental Microbiology Reports Oct 2023The gram-positive soil bacterium, Arthrobacter nicotianae, uses multiple organic acid functional groups to adsorb lanthanides onto its cell surface. At relevant soil pH...
The gram-positive soil bacterium, Arthrobacter nicotianae, uses multiple organic acid functional groups to adsorb lanthanides onto its cell surface. At relevant soil pH conditions of 4.0-6.0, many of these functional groups are de-protonated and available for cation sorption and metal immobilization. However, among the plethora of naturally occurring site types, A. nicotianae is shown to possess high-affinity amide and phosphate sites that disproportionately affect lanthanide adsorption to the cell wall. We quantify neodymium (Nd)-selective site types, reporting an amide-Nd stability constant of log K = 6.41 ± 0.23 that is comparable to sorption via phosphate-based moieties. These sites are two to three orders of magnitude more selective for Nd than the adsorption of divalent metals to ubiquitous carboxyl-based moieties. This implies the importance of lanthanide biosorption in the context of metal transport in subsurface systems despite trace concentrations of lanthanides found in the natural environment.
Topics: Lanthanoid Series Elements; Soil; Adsorption; Amides; Bacteria; Phosphates
PubMed: 37150598
DOI: 10.1111/1758-2229.13162 -
International Journal of Molecular... Jan 2021Phosphorous, in the form of phosphate, is a key element in the nutrition of all living beings. In nature, it is present in the form of phosphate salts,... (Review)
Review
Phosphorous, in the form of phosphate, is a key element in the nutrition of all living beings. In nature, it is present in the form of phosphate salts, organophosphates, and phosphonates. Bacteria transport inorganic phosphate by the high affinity phosphate transport system PstSCAB, and the low affinity PitH transporters. The PstSCAB system consists of four components. PstS is the phosphate binding protein and discriminates between arsenate and phosphate. In the species, the PstS protein, attached to the outer side of the cell membrane, is glycosylated and released as a soluble protein that lacks its phosphate binding ability. Transport of phosphate by the PstSCAB system is drastically regulated by the inorganic phosphate concentration and mediated by binding of phosphorylated PhoP to the promoter of the PstSCAB operon. In an additional high affinity transport system, PhnCDE, is also under PhoP regulation. Additionally, have a duplicated low affinity phosphate transport system encoded by the genes In this system phosphate is transported as a metal-phosphate complex in simport with protons. Expression of , but not that of in is regulated by PhoP. Interestingly, in many species, three gene clusters (for a polyphosphate kinase), are linked in a supercluster formed by nine genes related to phosphate metabolism. Glycerol-3-phosphate may be transported by the actinobacteria that contains a gene cluster for glycerol-3-P uptake, but the cluster is not present in genomes. Sugar phosphates and nucleotides are used as phosphate source by the species, but there is no evidence of the gene involved in the transport of sugar phosphates. Sugar phosphates and nucleotides are dephosphorylated by extracellular phosphatases and nucleotidases. An isolated gene for a hexose phosphate antiporter is present in several pathogenic corynebacteria, such as , but not in non-pathogenic ones. Phosphonates are molecules that contains phosphate linked covalently to a carbon atom through a very stable C-P bond. Their utilization requires the genes for phosphonates/phosphate transport and genes for degradation, including those for the subunits of the C-P lyase. Strains of the and genera were reported to degrade simple phosphonates, but bioinformatic analysis reveals that whole sets of genes for putative phosphonate degradation are present only in three species and a few species. Genes encoding the C-P lyase subunits occur in several species associated with plant roots or with mangroves, but not in the laboratory model species; however, the genes that encode phosphonates/phosphate transport systems are frequent in species, suggesting that these genes, in the absence of C-P lyase genes, might be used as surrogate phosphate transporters. In summary, and related actinobacteria seem to be less versatile in phosphate transport systems than Enterobacteria.
Topics: Actinobacteria; Arsenates; Bacterial Proteins; Biological Transport; Gene Expression Regulation, Bacterial; Glycosylation; Organophosphonates; Phosphate Transport Proteins; Phosphates; Phosphoric Monoester Hydrolases; Promoter Regions, Genetic; Signal Transduction; Streptomyces; Teichoic Acids
PubMed: 33498785
DOI: 10.3390/ijms22031129 -
Environmental Microbiology Reports Jun 2022Two related salmonids, Arctic char (Salvelinus alpinus) and lake whitefish (Coregonus clupeaformis) sampled from the high Arctic region of Nunavut, Canada are anadromous...
Two related salmonids, Arctic char (Salvelinus alpinus) and lake whitefish (Coregonus clupeaformis) sampled from the high Arctic region of Nunavut, Canada are anadromous fish, migrating annually from the same ice-covered freshwater waterbodies to spend summers in the marine waters of the Arctic Ocean. Microbiota associated with the skin-associated mucus undergo community change coincident with migration, and irrespective of this turnover, antibiotic resistance was detected in mixed bacterial cultures initiated with mucus samples. Although as expected most bacteria were unculturable, however, 5/7 isolates showed susceptibility to a panel of five common antibiotics. The fish were sampled under severe conditions and at remote locations far from human habitation. Regardless, two isolates, 'Carnobacterium maltaromaticum sm-2' and 'Arthrobacter citreus sm', showed multi-resistance to two or more antibiotics including ampicillin and streptomycin indicating multiple resistance genes. It is unknown if these fish bacteria have 'natural' resistance phenotypes or if resistance has been acquired. As result of these observations, we urge long-term monitoring of drug-resistant bacteria in the region and caution the assumption of a lack of drug-resistant organisms even in such extreme environments.
Topics: Animals; Anti-Bacterial Agents; Arctic Regions; Bacteria; Drug Resistance, Microbial; Fresh Water; Salmonidae; Trout
PubMed: 34109745
DOI: 10.1111/1758-2229.12975 -
Frontiers in Microbiology 2022Heat stress can have an impact on parental gamete maturation and reproduction functions. According to current research, the microbial composition of the vaginal cavity...
Heat stress can have an impact on parental gamete maturation and reproduction functions. According to current research, the microbial composition of the vaginal cavity is species specific. Pregnancy, menstruation, and genital diseases have been linked to the dynamics of vaginal ecology. In this study, we characterized the vaginal microbiota and metabolites after heat stress. At the phylum level, the rabbit's vaginal microbial composition of rabbit showed high similarity with that of humans. In the Heat group, the relative abundance of the dominant microbiota , , and increased, while the relative abundance of decreased. Furthermore, heat stress significantly increased the relative abundance of , , , , , and , whereas the relative abundance of 12 genera significantly decreased, including , , , , , , , , , , , and Besides, the relative concentrations of 158 metabolites differed significantly between the Heat and Control groups. Among them, the endocrine hormone estradiol (E) increased in the Heat group and was positively associated with a number of metabolites such as linolelaidic acid (C18:2N6T), N-acetylsphingosine, N-oleoyl glycine, trans-petroselinic acid, syringic acid, 2-(1-adamantyl)-1-morpholinoethan-1-one, 5-OxoETE, and 16-heptadecyne-1,2,4-triol. Further, the majority of the differential metabolites were enriched in steroid biosynthesis and endocrine and other factor-regulated calcium reabsorption pathways, reflecting that heat stress may affect calcium metabolism, hormone-induced signaling, and endocrine balance of vaginal ecology. These findings provide a comprehensive depiction of rabbit vaginal ecology and reveal the effects of heat stress on the vagina the analysis of vaginal microbiome and metabolome, which may provide a new thought for low female fertility under heat stress.
PubMed: 35495670
DOI: 10.3389/fmicb.2022.813622 -
Acta Crystallographica. Section F,... Apr 2020Human O-phosphoethanolamine phospho-lyase (hEtnppl; EC 4.2.3.2) is a pyridoxal 5'-phosphate-dependent enzyme that catalyzes the degradation of O-phosphoethanolamine...
Human O-phosphoethanolamine phospho-lyase (hEtnppl; EC 4.2.3.2) is a pyridoxal 5'-phosphate-dependent enzyme that catalyzes the degradation of O-phosphoethanolamine (PEA) into acetaldehyde, phosphate and ammonia. Physiologically, the enzyme is involved in phospholipid metabolism, as PEA is the precursor of phosphatidylethanolamine in the CDP-ethanolamine (Kennedy) pathway. Here, the crystal structure of hEtnppl in complex with pyridoxamine 5'-phosphate was determined at 2.05 Å resolution by molecular replacement using the structure of A1RDF1 from Arthrobacter aurescens TC1 (PDB entry 5g4i) as the search model. Structural analysis reveals that the two proteins share the same general fold and a similar arrangement of active-site residues. These results provide novel and useful information for the complete characterization of the human enzyme.
Topics: Carbon-Oxygen Lyases; Catalytic Domain; Crystallography, X-Ray; Cytidine Diphosphate; Ethanolamines; Humans; Models, Molecular; Protein Structure, Quaternary; Pyridoxal Phosphate
PubMed: 32254049
DOI: 10.1107/S2053230X20002988