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BMC Microbiology Aug 2023Phosphate-solubilizing bacteria (PSB) can solubilize insoluble phosphate compounds and improve phosphate availability in soil. Road verges are important in urban...
Isolation and characterization of phosphate-solubilizing bacteria from rhizosphere of poplar on road verge and their antagonistic potential against various phytopathogens.
BACKGROUND
Phosphate-solubilizing bacteria (PSB) can solubilize insoluble phosphate compounds and improve phosphate availability in soil. Road verges are important in urban landscaping, but the population structure of PSB and their ecological functions in the road verge soil is still unclear.
RESULTS
Twenty-one mineral PSB strains and 14 organic PSB strains were isolated from the rhizosphere of poplar on urban road verge. All the mineral PSB strains showed better solubilization to Ca(PO) than FePO or AlPO. Among them, 7 strains showed high phosphate-solubilizing (PS) activities to Ca(PO) (150-453 mg/L). All the organic PSB strains displayed weak solubilization to lecithin. 16S rRNA gene-based phylogenetic analysis showed good species diversity of the PSB strains, which belongs to 12 genera: Bacillus, Cedecea, Cellulosimicrobium, Delftia, Ensifer, Paenibacillus, Pantoea, Phyllobacterium, Pseudomonas, Rhizobium, Sinorhizobium and Staphylococcus. Moreover, 8 PSB strains showed various degrees of growth inhibition against 4 plant pathogenic fungi, Fusarium oxysporum S1, F. oxysporum S2, Pythium deliense Meurs Z4, Phomopsis sp. AC1 and a plant pathogenic bacterium, Pectobacterium carotovorum TP1.
CONCLUSIONS
The results indicated that these PSB strains could perform multiple ecological functions on road verge. The development and application of bio-agents based on the strains would provide a new strategy for maintaining and improving the ecosystem stability of road verges.
Topics: Rhizosphere; Phosphates; Populus; Soil Microbiology; Phylogeny; Soil; Bacteria; Ecosystem
PubMed: 37580699
DOI: 10.1186/s12866-023-02953-3 -
Frontiers in Medicine 2023Sepsis-associated liver dysfunction (SALD) has high incidence and mortality in patients with intra-abdominal infection (IAI). The associations between acute...
Acute gastrointestinal injury and altered gut microbiota are related to sepsis-induced cholestasis in patients with intra-abdominal infection: a retrospective and prospective observational study.
BACKGROUND
Sepsis-associated liver dysfunction (SALD) has high incidence and mortality in patients with intra-abdominal infection (IAI). The associations between acute gastrointestinal injury (AGI), gut microbiota, and SALD were evaluated in patients with IAI.
METHODS
A retrospective study was conducted to assess the relationship between AGI and SALD in patients with IAI. Patients were divided into non-SALD and sepsis-induced cholestasis () groups, which is a subtype of SALD. was defined as total bilirubin >2 mg/dL. AGI incidences between the two groups were compared using Chi-square test. Subsequently, a prospective study was conducted to investigate the gut microbiota differences between patients without SALD and those with . Fecal samples were collected on days 1, 3, and 7 after admission to analyze changes in gut microbiota using 16S ribosomal ribonucleic acid sequencing.
RESULTS
One hundred thirty-four patients with IAI were included retrospectively, with 77 SALD and 57 non-SALD cases. Among patients with SALD, 71 were diagnosed with . Patients with had a higher incidence of AGI compared to those without SALD (28.07% vs. 56.34%, < 0.05), and a severity-dependent relationship was found between AGI grade and occurrence. Subsequently, 20 patients with IAI were recruited prospectively, with 10 patients each assigned to the non-SALD and groups. Patients with had a more severe gut microbiota disorder on day 7 than those without SALD, including lower microbiota diversities, decreased abundance of and and increased abundance of and at the phylum level. Furthermore, and the two most abundant genera, were significantly higher in the group than in the non-SALD group. Functional prediction analysis showed that the top three KEGG pathways were ribosome, pyrimidine metabolism, and the two-component system. During the first week, the abundance of decreased significantly, whereas increased in the non-SALD group; however, the phyla taxa did not change significantly in the group.
CONCLUSION
There exists a severity-dependent relationship between AGI grade and occurrence in adult patients with IAI. A severe gut microbiota disorder was discovered in during the first week of the intensive care unit stay.
PubMed: 37575984
DOI: 10.3389/fmed.2023.1144786 -
Nutrients Jul 2023Exertional-heat stress (EHS) compromises intestinal epithelial integrity, potentially leading to the translocation of pathogenic agents into circulation. This study...
Exertional-heat stress (EHS) compromises intestinal epithelial integrity, potentially leading to the translocation of pathogenic agents into circulation. This study aimed to explore the impact of EHS on the systemic circulatory bacterial profile and to determine the impact of a short-term low (LFOD) and high (HFOD) fermentable oligo- di- mono-saccharide and polyol dietary intervention before EHS on this profile. Using a double-blind randomized cross-over design, thirteen endurance runners ( = 8 males, = 5 females), with a history of exercise-associated gastrointestinal symptoms (Ex-GIS), consumed a 24 h LFOD and HFOD before 2 h running at 60% V.O in 35.6 °C. Blood and fecal samples were collected pre-EHS to determine plasma microbial DNA concentration, and sample bacteria and short chain fatty acid (SCFA) profiles by fluorometer quantification, 16S rRNA amplicon gene sequencing, and gas chromatography, respectively. Blood samples were also collected post-EHS to determine changes in plasma bacteria. EHS increased plasma microbial DNA similarly in both FODMAP trials (0.019 ng·μL to 0.082 ng·μL) ( < 0.01). Similar pre- to post-EHS increases in plasma (+1.6%) and (+0.6%) phyla relative abundance were observed in both FODMAP trials. This included increases in several genus ( and ) groups. LFOD presented higher fecal (74%) and lower (10%) relative abundance pre-EHS, as a result of an increase in and family and respective genus groups, compared with HFOD (64% and 25%, respectively). Pre-EHS plasma total SCFA ( = 0.040) and acetate ( = 0.036) concentrations were higher for HFOD (188 and 178 μmol·L, respectively) vs. LFOD (163 and 153 μmol·L, respectively). Pre-EHS total fecal SCFA concentration (119 and 74 μmol·g; < 0.001), including acetate (74 and 45 μmol·g; = 0.001), butyrate (22 and 13 μmol·g; = 0.002), and propionate (20 and 13 μmol·g; = 0.011), were higher on HFOD vs LFOD, respectively. EHS causes the translocation of whole bacteria into systemic circulation and alterations to the plasma bacterial profile, but the FODMAP content of a 24 h diet beforehand does not alter this outcome.
PubMed: 37571312
DOI: 10.3390/nu15153376 -
Journal of Invertebrate Pathology Sep 2023The gut microflora plays an important role in insect development and physiology. The gut bacterial microbiome of the fall armyworm (FAW), Spodoptera frugiperda, in both...
The gut microflora plays an important role in insect development and physiology. The gut bacterial microbiome of the fall armyworm (FAW), Spodoptera frugiperda, in both cornfield and laboratory-reared populations was investigated using a 16S metagenomic approach. The alpha- and beta-diversity of the cornfield FAW populations varied among sampling sites and were higher than those of the laboratory-reared FAW population, indicating that different diets and environments influence the gut bacterial composition. To better understand the interaction between the microbiome and entomopathogenic fungi (EPF), FAWs from organic and conventionally managed corn fields and from the laboratory-reared colony were inoculated with Beauveria bassiana NCHU-153 (Bb-NCHU-153). A longer median lethal time (LT) was observed in the Bb-NCHU-153-infected cornfield FAW population than in the laboratory-reared FAWs. In terms of the microbiome, three Bb-NCHU-153-infected FAW groups showed different gut bacterial compositions compared to noninfected FAW. Further investigation of the cooccurrence network and linear discriminant analysis (LDA) of effect size (LEfSe) revealed that the enriched bacterial genera, such as Enterococcus, Serratia, Achromobacter, and Tsukamurella, in the gut might play the role of opportunistic pathogens after fungal infection; in contrast, some gut bacteria of Methylobacterium, Marinomonas, Paenochrobactrum, Pseudomonas, Acinetobacter, Delftia, Dietzia, Gordonia, Leucobacter, Paracoccus, and Stenotrophomonas might be probiotics against EPF infection. These results indicated that EPF infection can change the gut bacterial composition and lead to a pathobiome in the FAW and that some bacterial species might protect the FAW from EPF infection. These findings could be applied to the design of pathobiome-inducing biocontrol strategies.
Topics: Animals; Spodoptera; Gastrointestinal Microbiome; Zea mays; Beauveria; Larva
PubMed: 37541570
DOI: 10.1016/j.jip.2023.107976 -
Science (New York, N.Y.) Aug 2023Malaria control demands the development of a wide range of complementary strategies. We describe the properties of a naturally occurring, non-genetically modified...
Malaria control demands the development of a wide range of complementary strategies. We describe the properties of a naturally occurring, non-genetically modified symbiotic bacterium, TC1, which was isolated from mosquitoes incapable of sustaining the development of parasites. TC1 inhibits early stages of development and subsequent transmission by the mosquito through secretion of a small-molecule inhibitor. We have identified this inhibitor to be the hydrophobic molecule harmane. We also found that, on mosquito contact, harmane penetrates the cuticle, inhibiting development. TC1 stably populates the mosquito gut, does not impose a fitness cost on the mosquito, and inhibits development for the mosquito's life. Contained field studies in Burkina Faso and modeling showed that TC1 has the potential to complement mosquito-targeted malaria transmission control.
Topics: Animals; Anopheles; Malaria, Falciparum; Plasmodium falciparum; Delftia; Symbiosis; Humans; Host-Parasite Interactions
PubMed: 37535741
DOI: 10.1126/science.adf8141 -
Improvement of growth, yield and associated bacteriome of rice by the application of probiotic and .Frontiers in Microbiology 2023Plant probiotic bacteria enhance growth and yield of crop plants when applied at the appropriate time and dose. Two rice probiotic bacteria, strain BRRh-4 and sp....
Plant probiotic bacteria enhance growth and yield of crop plants when applied at the appropriate time and dose. Two rice probiotic bacteria, strain BRRh-4 and sp. strain BTL-M2 promote growth and yield of plants. However, no information is available on application of these two bacteria on growth, yield, and diversity and population of bacteriome in roots and rhizosphere soils of the treated rice plants. This study aimed to assess the effect of BRRh-4 and BTL-M2 application on growth, yield and bacteriome in roots and rhizosphere soil of rice under varying doses of N, P and K fertilizers. Application of BRRh-4 and BTL-M2 strains significantly ( < 0.05) increased seed germination, growth and yield of rice compared to an untreated control. Interestingly, the grain yield of rice by these bacteria with 50% less of the recommended doses of N, P, and K fertilizers were statistically similar to or better than the rice plants treated with 100% doses of these fertilizers. Targeted amplicon (16S rRNA) sequence-based analysis revealed significant differences (PERMANOVA, = 0.00035) in alpha-diversity between the root (R) and rhizosphere soil (S) samples, showing higher diversity in the microbial ecosystem of root samples. Additionally, the bacteriome diversity in the root of rice plants that received both probiotic bacteria and chemical fertilizers were significantly higher (PERMANOVA, = 0.0312) compared to the rice plants treated with fertilizers only. Out of 185 bacterial genera detected, , an anaerobic and Gram-negative bacterium, was found to be the predominant genus in both rhizosphere soil and root metagenomes. However, the relative abundance of remained two-fold higher in the rhizosphere soil metagenome (52.02%) than in the root metagenome (25.04%). The other predominant bacterial genera detected in the rice root metagenome were (11.07%), (4.06%), (3.91%), (2.97%), (2.61%), and (2.30%). On the other hand, rhizosphere soil metagenome had (12.38%), (9.50%), (5.94%), (3.40%), and (3.02%). Interestingly, we found the presence and/or abundance of specific genera of bacteria in rice associated with the application of a specific probiotic bacterium. Taken together, our results indicate that improvement of growth and yield of rice by strain BRRh-4 and sp. strain BTL-M2 is likely linked with modulation of diversity, structures, and signature of bacteriome in roots and rhizosphere soils. This study for the first time demonstrated that application of plant growth promoting bacteria significantly improve growth, yield and increase the diversity of bacterial community in rice.
PubMed: 37520368
DOI: 10.3389/fmicb.2023.1212505 -
Food & Function Aug 2023The prevalence of oral health problems is ubiquitous in contemporary society, with particular emphasis placed on the central role of oral flora in mitigating this issue....
The prevalence of oral health problems is ubiquitous in contemporary society, with particular emphasis placed on the central role of oral flora in mitigating this issue. Both ancient literature and modern research have highlighted the promising application of tea with substantial bioactive properties, particularly dark tea, in preserving and promoting oral health. Liubao tea, a widely consumed dark tea with increasing popularity in recent years, has been reported to possess abundant bioactive constituents, exhibit remarkable antioxidant and anti-inflammatory effects, modulate the flora structure and so on. It may be a promising candidate for addressing oral health problems. In this study, Liubao tea was meticulously extracted, purified and identified, followed by an investigation of its potential to modulate oral microecology by virtue of an acetic acid-induced oral disorder murine model. The results revealed that Liubao tea extract (LTE) application commendably reconstructed the oral mucosal barrier, promoted tissue regeneration and mitigated micro-inflammation. Furthermore, LTE treatment could also ameliorate the oral flora composition by decreasing the abundance of and increasing the abundance of and at the phylum level, as well as inhibiting pernicious bacteria such as and . So, it could promote the generation of a beneficial microenvironment and regulate the immune process. Overall, LTE demonstrated remarkable potential in regulating the balance of oral microecology, suggesting that it may represent a promising therapeutic strategy for oral health concerns.
PubMed: 37475617
DOI: 10.1039/d3fo02277c -
Frontiers in Microbiology 2023The aim of this study was to compare the effect of different additives on nutritional quality, fermentation variables and microbial diversity of hybrid silages. A...
The aim of this study was to compare the effect of different additives on nutritional quality, fermentation variables and microbial diversity of hybrid silages. A control (CK - no additives) and seven treatments were tested, namely, (LP), (LB), propionic acid (PA), calcium propionate (CAP), LP + LB; LP + PA and LP + CAP. In comparison with CK, all treatments increased the contents of crude protein and lactic acid, decreased the content of butyric acid, and altered the bacterial communities of the silage. Except for the CAP and LP + CAP treatments, the additives decreased pH and the ammonia nitrogen:total nitrogen (NH-N:TN) ratio. The results of principal component analysis revealed that the PA, LP + PA and LP + LB treatments ranked as the top three silages. The PA and LP + PA treatments exhibited higher water-soluble carbohydrate content, but lower pH, and NH-N:TN ratio than the other treatments. With the PA and LP + PA treatments, the relative abundances of and decreased, and of and increased, while the carbohydrate metabolism of the microorganisms improved. The LP and LB treatments reduced the Shannon and Simpson diversities. In the beta diversity, PA and LP + PA separated from the other treatments, indicating that there were differences in the composition of bacterial species. The relative abundance of increased in the LP and LB treatments and of and increased in the CAP and LP + CAP treatments. In summary, the addition of , , propionic acid, calcium propionate, and their combinations improved fermentation quality, inhibited harmful bacteria and conserved the nutrients of hybrid .
PubMed: 37455750
DOI: 10.3389/fmicb.2023.1216722 -
Frontiers in Plant Science 2023The endosphere of a plant is an interface containing a thriving community of endobacteria that can affect plant growth and potential for bioremediation. is an aquatic...
INTRODUCTION
The endosphere of a plant is an interface containing a thriving community of endobacteria that can affect plant growth and potential for bioremediation. is an aquatic macrophyte, adapted to estuarine and freshwater ecosystems, which harbors a diverse bacterial community. Despite this, we currently lack a predictive understanding of how taxonomically structure the endobacterial community assemblies across distinct habitats (root, stem, and leaf).
METHODS
In the present study, we assessed the endophytic bacteriome from different compartments using 16S rRNA gene sequencing analysis and verified the plant beneficial potential of isolated bacterial endophytes of .
RESULTS AND DISCUSSION
Plant compartments displayed a significant impact on the endobacterial community structures. Stem and leaf tissues were more selective, and the community exhibited a lower richness and diversity than root tissue. The taxonomic analysis of operational taxonomic units (OTUs) showed that the major phyla belonged to Proteobacteria and Actinobacteriota (> 80% in total). The most abundant genera in the sampled endosphere was in both stem and leaf samples. Members of the family Rhizobiaceae, such as in both stem and leaf samples. Members of the family Rhizobiaceae, such as were mainly associated with leaf tissue, whereas the genera and from the families Nannocystaceae and Nitrospiraceae, respectively, were statistically significantly associated with root tissue. were putative keystone taxa of stem tissue. Most of the endophytic bacteria isolated from showed plant beneficial effects known to stimulate plant growth and induce plant resistance to stresses. This study provides new insights into the distribution and interaction of endobacteria across different compartments of Future study of endobacterial communities, using both culture-dependent and -independent techniques, will explore the mechanisms underlying the wide-spread adaptability of to various ecosystems and contribute to the development of efficient bacterial consortia for bioremediation and plant growth promotion.
PubMed: 37404529
DOI: 10.3389/fpls.2023.1176648 -
Microbial Ecology Nov 2023Agricultural crops are exposed to various abiotic and biotic stresses that can constrain crop productivity. Focusing on a limited subset of key groups of organisms has...
Agricultural crops are exposed to various abiotic and biotic stresses that can constrain crop productivity. Focusing on a limited subset of key groups of organisms has the potential to facilitate the monitoring of the functions of human-managed ecosystems. Endophytic bacteria can enhance plant stress resistance and can help plants to cope with the negative impacts of stress factors through the induction of different mechanisms, influencing plant biochemistry and physiology. In this study, we characterise endophytic bacteria isolated from different plants based on their metabolic activity and ability to synthesise 1-aminocyclopropane-1-carboxylic acid deaminase (ACCD), the activity of hydrolytic exoenzymes, the total phenolic compounds (TPC) and iron-complexing compounds (ICC). Test GEN III MicroPlate indicated that the evaluated endophytes are highly metabolically active, and the best used substrates were amino acids, which may be important in selecting potential carrier components for bacteria in biopreparations. The ACCD activity of strain ES2 (Stenotrophomonas maltophilia) was the highest, whereas that of strain ZR5 (Delftia acidovorans) was the lowest. Overall, the obtained results indicated that ∼91.3% of the isolates were capable of producing at least one of the four hydrolytic enzymes. In addition, most of the tested strains produced ICC and TPC, which play a significant role in reducing stress in plants. The results of this study suggest that the tested endophytic bacterial strains can potentially be used to mitigate climate change-associated stresses in plants and to inhibit plant pathogens.
Topics: Humans; Ecosystem; Bacteria; Endophytes; Crops, Agricultural; Stress, Physiological
PubMed: 37392205
DOI: 10.1007/s00248-023-02260-4