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BMC Plant Biology Jun 2022Chemical fertilisers are extensively used for crop production, which may cause soil deterioration and water pollution. Endophytic bacteria with plant-growth-promoting...
BACKGROUND
Chemical fertilisers are extensively used for crop production, which may cause soil deterioration and water pollution. Endophytic bacteria with plant-growth-promoting (PGP) activities may provide a solution to sustainably improve crop yields, including in-demand staples such as wheat. However, the diversity of the PGP endophytic bacteria in wheat across plant organs and growth stages has not been thoroughly characterised.
RESULTS
Here, we report the isolation of endophytic bacteria from root, stem, leaf and seed of three winter wheat varieties at tillering, jointing, heading and seed-filling growth stages that were identified via 16S rRNA gene sequence analysis. Strains were screened for indole-3-acetic acid (IAA) production, potassium and phosphate solubilisation and the ability to grow on a nitrogen-free medium. Strain's capacity to stimulate various plant growth parameters, such as dry root weight, dry above-ground parts weight and plant height, was evaluated in pot trials. A total of 127 strains were randomly selected from 610 isolated endophytic bacterial cultures, representing ten genera and 22 taxa. Some taxa were organ-specific; others were growth-stage-specific. Bacillus aryabhattai, B. stratosphericus, Leclercia adecarboxylata and Pseudomonas oryzihabitans were detected as wheat endophytes for the first time. The IAA production, inorganic phosphorous solubilisation, organic phosphorus solubilisation, potassium solubilisation and growth on N-free medium were detected in 45%, 29%, 37%, 2.4% and 37.8% of the 127 strains, respectively. In pot trials, each strain showed variable effects on inoculated wheat plants regarding the evaluated growth parameters.
CONCLUSIONS
Wheat endophytic bacteria showed organ- and growth-stage diversity, which may reflect their adaptations to different plant tissues and seasonal variations, and differed in their PGP abilities. Bacillus was the most predominant bacterial taxa isolated from winter wheat plants. Our study confirmed wheat root as the best reservoir for screening endophytic bacteria with potential as biofertilisers.
Topics: Bacteria; Endophytes; Phylogeny; Plant Roots; Potassium; RNA, Ribosomal, 16S; Triticum
PubMed: 35659526
DOI: 10.1186/s12870-022-03615-8 -
Journal of Medical Case Reports Mar 2017Pseudomonas oryzihabitans is a Pseudomonas bacterial organism rarely implicated in human infections. The bacterium has been isolated in a few reported cases of...
BACKGROUND
Pseudomonas oryzihabitans is a Pseudomonas bacterial organism rarely implicated in human infections. The bacterium has been isolated in a few reported cases of neurosurgical infections and patients with end-stage cirrhosis, sickle cell disease, and community-acquired urinary tract infections. Limited information exists in developing countries, however, because of the lack of advanced microbiological tools for identification and characterization of this bacterium. This case report describes the isolation of a rare Pseudomonas bacterium in a patient presenting with sepsis and skin infection.
CASE PRESENTATION
A 1-year-old girl was presented to a hospital in the northeastern part of Ghana with a 1-week history of pustular rashes on her scalp and neck, which occasionally ruptured, along with discharge of yellowish purulent fluid. The child is of Mole-Dagbon ethnicity and hails from the northern part of Ghana. Pseudomonas oryzihabitans was identified in the patient's blood culture using the 16S ribosomal deoxyribonucleic acid sequencing technique. The rash on the patient's scalp and skin resolved after continuous treatment with gentamicin while her condition improved clinically.
CONCLUSIONS
This finding suggests the potential of this bacterium to cause disease in unsuspected situations and emphasizes the need to have evidence for the use of the appropriate antibiotic in clinical settings, particularly in rural settings in Africa. It also brings to the fore the unreliability of conventional methods for identification of Pseudomonas bacteria in clinical samples and thus supports the use of 16S ribosomal deoxyribonucleic acid in making the diagnosis.
Topics: Anti-Bacterial Agents; Exanthema; Female; Gentamicins; Ghana; Humans; Infant; Neck; Pseudomonas; Pseudomonas Infections; RNA, Ribosomal, 16S; Scalp; Sepsis; Treatment Outcome
PubMed: 28330494
DOI: 10.1186/s13256-017-1230-6 -
Nanomaterials (Basel, Switzerland) Sep 2021We studied the effects of new chemically synthesized selenium (Se) nanocomposites (NCs) based on natural polysaccharide matrices arabinogalactan (AG), starch (ST), and...
We studied the effects of new chemically synthesized selenium (Se) nanocomposites (NCs) based on natural polysaccharide matrices arabinogalactan (AG), starch (ST), and kappa-carrageenan (CAR) on the viability of phytopathogen , rhizospheric bacteria, and potato productivity in the field experiment. Using transmission electron microscopy (TEM), it was shown that the nanocomposites contained nanoparticles varying from 20 to 180 nm in size depending on the type of NC. All three investigated NCs had a fungicidal effect even at the lowest tested concentrations of 50 µg/mL for Se/AG NC (3 µg/mL Se), 35 µg/mL for Se/ST NC (0.5 µg/mL Se), and 39 µg/mL for Se/CAR NC (1.4 µg/mL Se), including concentration of 0.000625% Se (6.25 µg/mL) in the final suspension, which was used to study Se NC effects on bacterial growth of the three common rhizospheric bacteria , and isolated from the rhizosphere of plants growing in the Irkutsk Region, Russia. The AG-based Se NC (Se/AG NC) and CAR-based Se NC (Se/CAR NC) exhibited the greatest inhibition of fungal growth up to 60% (at 300 µg/mL) and 49% (at 234 µg/mL), respectively. The safe use of Se NCs against phytopathogens requires them to be environmentally friendly without negative effects on rhizospheric microorganisms. The same concentration of 0.000625% Se (6.25 µg/mL) in the final suspension of all three Se NCs (which corresponds to 105.57 µg/mL for Se/AG NC, 428.08 µg/mL for Se/ST NC and 170.30 µg/mL for Se/CAR NC) was used to study their effect on bacterial growth (bactericidal, bacteriostatic, and biofilm formation effects) of the three rhizospheric bacteria. Based on our earlier studies this concentration had an antibacterial effect against the phytopathogenic bacterium that causes diseases of potato ring rot, but did not negatively affect the viability of potato plants at this concentration. In this study, using this concentration no bacteriostatic and bactericidal activity of all three Se NCs were found against based on the optical density of a bacterial suspension, agar diffusion, and intensity of biofilm formation, but Se/CAR and Se/AG NCs inhibited the growth of . The cell growth was decrease by 15-30% during the entire observation period, but the stimulation of biofilm formation by this bacterium was observed for Se/CAR NC. Se/AG NC also had bacteriostatic and antibiofilm effects on the rhizospheric bacterium . There was a 2.5-fold decrease in bacterial growth and a 30% decrease in biofilm formation, but Se/CAR NC stimulated the growth of . According to the results of the preliminary field test, an increase in potato productivity by an average of 30% was revealed after the pre-planting treatment of tubers by spraying them with Se/AG and Se/CAR NCs with the same concentration of Se of 0.000625% (6.25 µg/mL) in a final suspension. The obtained and previously published results on the positive effect of natural matrix-based Se NCs on plants open up prospects for further investigation of their effects on rhizosphere bacteria and resistance of cultivated plants to stress factors.
PubMed: 34578589
DOI: 10.3390/nano11092274 -
Antibiotics (Basel, Switzerland) Jun 2022This study is focused on resistance to carbapenems and third-generation cephalosporins in Gram-negative microorganisms isolated from swine, whose transmission to humans...
This study is focused on resistance to carbapenems and third-generation cephalosporins in Gram-negative microorganisms isolated from swine, whose transmission to humans via pork consumption cannot be excluded. In addition, the common carriage of carbapenem-resistant (CR) bacteria between humans and pigs was evaluated. Sampling involved 300 faecal samples collected from slaughtered pigs and 300 urine samples collected from 187 hospitalised patients in Parma Province (Italy). In swine, MIC testing confirmed resistance to meropenem for isolates of and and resistance to cefotaxime and ceftazidime for , , , and . For , , , , and , no EUCAST MIC breakpoints were available. However, ESBL genes (, , , and ) and AmpC genes (, , and ) were found in 38 and 16 isolates, respectively. was the only CR species shared by pigs (4/300 pigs; 1.3%) and patients (2/187; 1.1%). ST938 carrying and was detected in one pig as well as an 83-year-old patient. Although no direct epidemiological link was demonstrable, SNP calling and cgMLST showed a genetic relationship of the isolates (86 SNPs and 661 allele difference), thus suggesting possible circulation of CR bacteria between swine and humans.
PubMed: 35740183
DOI: 10.3390/antibiotics11060777 -
Biotechnology Reports (Amsterdam,... Dec 2021In this study, three wastes based on potato peels and pulps, tomato seeds and wheat bran were used as basis for the preparation of a cheap medium to produce the...
In this study, three wastes based on potato peels and pulps, tomato seeds and wheat bran were used as basis for the preparation of a cheap medium to produce the bacterium PGP01. In flasks experiments, PGP01 growth at 25 °C in a medium based on frozen potato peels and pulp (FPP) with tryptone as a nitrogen source resulted in the maximum production compared to the commercial TSB medium. In the scale-up to 2 L bioreactors, FPP supplemented with tryptone, molasses, NaCl and KHPO allowed to reach similar biomass production than in the TSB medium. A maximum growth of 4.4 × 10 CFU mL after setting the agitation and the air flux conditions at 400 rpm and 0.75 vvm. Finally, PGP01 growing in this optimized medium conserved its biological activity showing the expected effect in root development previously reported for this microorganism.
PubMed: 34603978
DOI: 10.1016/j.btre.2021.e00675 -
Microorganisms Apr 2023The aim of this work was to assess the natural microbiota of packed fresh-cut apples during refrigerated storage. Two different films were tested for the package, a...
The aim of this work was to assess the natural microbiota of packed fresh-cut apples during refrigerated storage. Two different films were tested for the package, a biodegradable (PLA) film and a conventional and commercial one (OPP). Two antioxidant additives were applied, a natural olive pomace extract and the commercial ascorbic acid used by the industries. The results revealed lower bacteria counts in samples with olive pomace extract and PLA films than in those with ascorbic acid and OPP films after 5 and 12 days of storage. These findings suggest that the use of such natural extracts as additives in fruits could delay the growth of mesophilic bacteria. The characterization and identification of the bacterial isolates from fresh-cut apple samples showed that the most prevalent species were , , , , , spp., and spp. Furthermore, an increase in the microbial diversity during the storage time at refrigerated temperatures was observed, except for the sample treated with olive pomace extract and packaged in OPP film. The highest microbial diversity was found for samples with ascorbic acid as an additive. This could indicate a negative effect of ascorbic acid on the microbial inhibition of apple slices. The natural olive pomace extract demonstrated potential as an antimicrobial additive for fresh-cut apples.
PubMed: 37317130
DOI: 10.3390/microorganisms11051157 -
Frontiers in Microbiology 2021Phyllosphere-the harsh foliar plant part exposed to vagaries of environmental and climatic variables is a unique habitat for microbial communities. In the present work,...
Phyllosphere-the harsh foliar plant part exposed to vagaries of environmental and climatic variables is a unique habitat for microbial communities. In the present work, we profiled the phyllosphere microbiome of the rice plants using 16S rRNA gene amplicon sequencing (hereafter termed metabarcoding) and the conventional microbiological methods (culturomics) to decipher the microbiome assemblage, composition, and their functions such as antibiosis and defense induction against rice blast disease. The blast susceptible rice genotype (PRR78) harbored far more diverse bacterial species (294 species) than the resistant genotype (Pusa1602) that showed 193 species. Our metabarcoding of bacterial communities in phyllomicrobiome revealed the predominance of the phylum, Proteobacteria, and its members , , , and on the phyllosphere of both rice genotypes. The microbiological culturomic validation of metabarcoding-taxonomic annotation further confirmed the prevalence of 31 bacterial isolates representing 11 genera and 16 species with the maximum abundance of The phyllomicrobiome-associated bacterial members displayed antifungal activity on rice blast fungus, , by volatile and non-volatile metabolites. Upon phyllobacterization of rice cultivar PB1, the bacterial species such as , , , , , , sp., and sp. elicited a defense response and contributed to the suppression of blast disease. qRT-PCR-based gene expression analysis indicated over expression of defense-associated genes such as , , and phytohormone-associated genes such as , , , , , and in phyllobacterized rice seedlings. The phyllosphere bacterial species showing blast suppressive activity on rice were found non-plant pathogenic in tobacco infiltration assay. Our comparative microbiome interrogation of the rice phyllosphere culminated in the isolation and identification of agriculturally significant bacterial communities for blast disease management in rice farming through phyllomicrobiome engineering in the future.
PubMed: 34917058
DOI: 10.3389/fmicb.2021.780458 -
Frontiers in Plant Science 2021Plant-associated beneficial strains inhabiting plants grown under harsh ecosystems can help them cope with abiotic stress factors by positively influencing plant...
Plant-associated beneficial strains inhabiting plants grown under harsh ecosystems can help them cope with abiotic stress factors by positively influencing plant physiology, development, and environmental adaptation. Previously, we isolated a potential plant growth promoting strain (AXSa06) identified as , possessing 1-aminocyclopropane-1-carboxylate deaminase activity, producing indole-3-acetic acid and siderophores, as well as solubilizing inorganic phosphorus. In this study, we aimed to further evaluate the effects of AXSa06 seed inoculation on the growth of tomato seedlings under excess salt (200 mM NaCl) by deciphering their transcriptomic and metabolomic profiles. Differences in transcript levels and metabolites following AXSa06 inoculation seem likely to have contributed to the observed difference in salt adaptation of inoculated plants. In particular, inoculations exerted a positive effect on plant growth and photosynthetic parameters, imposing plants to a primed state, at which they were able to respond more robustly to salt stress probably by efficiently activating antioxidant metabolism, by dampening stress signals, by detoxifying Na, as well as by effectively assimilating carbon and nitrogen. The primed state of AXSa06-inoculated plants is supported by the increased leaf lipid peroxidation, ascorbate content, as well as the enhanced activities of antioxidant enzymes, prior to stress treatment. The identified signatory molecules of AXSa06-mediated salt tolerance included the amino acids aspartate, threonine, serine, and glutamate, as well as key genes related to ethylene or abscisic acid homeostasis and perception, and ion antiporters. Our findings represent a promising sustainable solution to improve agricultural production under the forthcoming climate change conditions.
PubMed: 34484277
DOI: 10.3389/fpls.2021.713984 -
Microorganisms Sep 2021Aspens ( and its hybrids), economically and ecologically important fast-growing trees, are often damaged by , a rot-causing fungus. Plant-associated bacteria can be used...
Aspens ( and its hybrids), economically and ecologically important fast-growing trees, are often damaged by , a rot-causing fungus. Plant-associated bacteria can be used to increase plant growth and resistance; however, no systematic studies relating the activity of symbiotic bacteria to aspen resistance against have been conducted so far. The present pioneer study investigated the responses of two and two × genotypes to in vitro inoculations with, first, either sp. or sp. bacteria (isolated originally from hybrid aspen tissue cultures and being most closely related to and , respectively) and, in the subsequent stage, with . Both morphological parameters of in vitro-grown plants and biochemical content of their leaves, including photosynthesis pigments and secondary metabolites, were analyzed. It was found that both × genotypes, whose development in vitro was significantly damaged by , were characterized by certain responses to the studied bacteria: decreased shoot development by both sp. and sp. and increased phenol content by sp. In turn, these responses were lacking in both genotypes that showed in vitro resistance to the fungus. Moreover, these genotypes showed positive long-term growth responses to bacterial inoculation, even synergistic with the subsequent fungal inoculation. Hence, the studied bacteria were demonstrated as a potential tool for the improved in vitro propagation of fungus-resistant aspen genotypes.
PubMed: 34576797
DOI: 10.3390/microorganisms9091901 -
Standards in Genomic Sciences 2017We report here the draft genome sequences of eight bacterial strains of the genera , and . These isolates were obtained from aerosol sampling of bathrooms of five...
Draft genome sequences of eight bacteria isolated from the indoor environment: strain H36, strain H65, strain H62, strain H69, sp. strain H83, strain H39, sp. strain H53, and strain H72.
We report here the draft genome sequences of eight bacterial strains of the genera , and . These isolates were obtained from aerosol sampling of bathrooms of five residences in the San Francisco Bay area. Taxonomic classifications as well as the genome sequence and gene annotation of the isolates are described. As part of the "Built Environment Reference Genome" project, these isolates and associated genome data provide valuable resources for studying the microbiology of the built environment.
PubMed: 28163826
DOI: 10.1186/s40793-017-0223-9