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Frontiers in Microbiology 2024Legumes are renowned for their distinctive biological characteristic of forming symbiotic associations with soil bacteria, mostly belonging to the familiy, leading to... (Review)
Review
Legumes are renowned for their distinctive biological characteristic of forming symbiotic associations with soil bacteria, mostly belonging to the familiy, leading to the establishment of symbiotic root nodules. Within these nodules, rhizobia play a pivotal role in converting atmospheric nitrogen into a plant-assimilable form. However, it has been discerned that root nodules of legumes are not exclusively inhabited by rhizobia; non-rhizobial endophytic bacteria also reside within them, yet their functions remain incompletely elucidated. This comprehensive review synthesizes available data, revealing that and are the most prevalent genera of nodule endophytic bacteria, succeeded by , , , , and . To date, the bibliographic data available show that followed by and are the main hosts for nodule endophytic bacteria. Clustering analysis consistently supports the prevalence of and as the most abundant nodule endophytic bacteria, alongside , , and . Although non-rhizobial populations within nodules do not induce nodule formation, their presence is associated with various plant growth-promoting properties (PGPs). These properties are known to mediate important mechanisms such as phytostimulation, biofertilization, biocontrol, and stress tolerance, emphasizing the multifaceted roles of nodule endophytes. Importantly, interactions between non-rhizobia and rhizobia within nodules may exert influence on their leguminous host plants. This is particularly shown by co-inoculation of legumes with both types of bacteria, in which synergistic effects on plant growth, yield, and nodulation are often measured. Moreover these effects are pronounced under both stress and non-stress conditions, surpassing the impact of single inoculations with rhizobia alone.
PubMed: 38812696
DOI: 10.3389/fmicb.2024.1386742 -
Microbial Cell Factories May 2024Biosynthesis of metallic nanoparticles using microorganisms are a fabulous and emerging eco-friendly science with well-defined sizes, shapes and controlled... (Comparative Study)
Comparative Study
BACKGROUND
Biosynthesis of metallic nanoparticles using microorganisms are a fabulous and emerging eco-friendly science with well-defined sizes, shapes and controlled monodispersity. Copper nanoparticles, among other metal particles, have sparked increased attention due to their applications in electronics, optics, catalysis, and antimicrobial agents.
RESULTS
This investigation explains the biosynthesis and characterization of copper nanoparticles from soil strains, Niallia circulans G9 and Paenibacillus sp. S4c by an eco-friendly method. The maximum reduction of copper ions and maximum synthesis CuNPs was provided by these strains. Biogenic formation of CuNPs have been characterized by UV-visible absorption spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray analysis and transmission electron microscopy analysis. Using UV-visible spectrum scanning, the synthesised CuNPs' SPR spectra showed maximum absorption peaks at λ. TEM investigation of the produced CuNPs revealed the development of spherical/hexagonal nanoparticles with a size range of 13-100 nm by the G9 strain and spherical nanoparticles with a size range of 5-40 nm by the S4c strain. Functional groups and chemical composition of CuONPs were also confirmed. The antimicrobial activity of the biosynthesized CuNPs were investigated against some human pathogens. CuNPs produced from the G9 strain had the highest activity against Candida albicans ATCC 10,231 and the lowest against Pseudomonas aeruginosa ATCC 9027. CuNPs from the S4c strain demonstrated the highest activity against Escherichia coli ATCC 10,231 and the lowest activity against Klebsiella pneumonia ATCC 13,883.
CONCLUSION
The present work focused on increasing the CuNPs production by two isolates, Niallia circulans G9 and Paenibacillus sp. S4c, which were then characterized alongside. The used analytics and chemical composition techniques validated the existence of CuONPs in the G9 and S4c biosynthesized nano cupper. CuNPs of S4c are smaller and have a more varied shape than those of G9 strain, according to TEM images. In terms of antibacterial activity, the biosynthesized CuNPs from G9 and S4c were found to be more effective against Candida albicans ATCC 10,231 and E. coli ATCC 10,231, respectively.
Topics: Paenibacillus; Metal Nanoparticles; Copper; Anti-Infective Agents; Microbial Sensitivity Tests; Anti-Bacterial Agents; Ascomycota
PubMed: 38802818
DOI: 10.1186/s12934-024-02422-0 -
New Microbes and New Infections Jun 2024
PubMed: 38799939
DOI: 10.1016/j.nmni.2024.101372 -
New Microbes and New Infections Jun 2024
Expression of Concern: Noncontiguous finished genome sequences and descriptions of Paenibacillus bouchesdurhonensis,' Paenibacillus rubinfantis,' Paenibacillus senegalimassiliensis' and Paenibacillus tuaregi' identified by culturomics.
PubMed: 38799856
DOI: 10.1016/j.nmni.2024.101366 -
New Microbes and New Infections Jun 2024
PubMed: 38799841
DOI: 10.1016/j.nmni.2024.101362 -
Biochar 2024While many studies have examined the role of biochar in carbon (C) accrual in short-term scale, few have explored the decadal scale influences of biochar on non-biochar...
Distinct biophysical and chemical mechanisms governing sucrose mineralization and soil organic carbon priming in biochar amended soils: evidence from 10 years of field studies.
UNLABELLED
While many studies have examined the role of biochar in carbon (C) accrual in short-term scale, few have explored the decadal scale influences of biochar on non-biochar C, e.g., native soil organic C (SOC) and added substrate. To address this knowledge gap, soils were collected from decade-old biochar field trials located in the United Kingdom (Cambisol) and China (Fluvisol), with each site having had three application rates (25-30, 50-60 and 75-100 Mg ha) of biochar plus an unamended Control, applied once in 2009. We assessed physicochemical and microbial properties associated with sucrose (representing the rhizodeposits) mineralization and the priming effect (PE) on native SOC. Here, we showed both soils amended with biochar at the middle application rate (50 Mg ha biochar in Cambisol and 60 Mg ha biochar in Fluvisol) resulted in greater substrate mineralization. The enhanced accessibility and availability of sucrose to microorganisms, particularly fast-growing bacterial genera like and (r-strategists belonging to the Proteobacteria and Firmicutes phyla, respectively), can be attributed to the improved physicochemical properties of the soil, including pH, porosity, and pore connectivity, as revealed by synchrotron-based micro-CT. Random forest analysis also confirmed the contribution of the microbial diversity and physical properties such as porosity on sucrose mineralization. Biochar at the middle application rate, however, resulted in the lowest PE (0.3 and 0.4 mg of CO-C g soil in Cambisol and Fluvisol, respectively) after 53 days of incubation. This result might be associated with the fact that the biochar promoted large aggregates formation, which enclosed native SOC in soil macro-aggregates (2-0.25 mm). Our study revealed a diverging pattern between substrate mineralization and SOC priming linked to the biochar application rate. This suggests distinct mechanisms, biophysical and physicochemical, driving the mineralization of non-biochar carbon in a field where biochar was applied a decade before.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s42773-024-00327-0.
PubMed: 38799721
DOI: 10.1007/s42773-024-00327-0 -
Food Chemistry Oct 2024The influence of four microbial biostimulants containing various strains of Bacillus subtilis and/or Paenibacillus sp. on the quality of raspberries cv. Delniwa, Poemat,...
The influence of four microbial biostimulants containing various strains of Bacillus subtilis and/or Paenibacillus sp. on the quality of raspberries cv. Delniwa, Poemat, and Enrosadira cultivated in two consecutive seasons was investigated. The biostimulants influenced the antioxidant level, antioxidant capacity, phenolic acids and flavonoids profiles, enzymatic activity, and the degree of methylation and acetylation of the pectin in the raspberry fruits. The biostimulants had the greatest effect on the antioxidant content (16% - 20% increase) and capacity in the Delniwa raspberry fruits from the first season. A positive correlation was found between the activity of the β-galactosidase enzyme and ferric reducing power. In the second season, a decrease in the activity of pectin esterase and α-L-arabinofuranosidase and an increase in the degree of methylation of pectin were noted. Our results suggest that the changes in raspberry quality were related to the type of biostimulant applied.
Topics: Antioxidants; Rubus; Fruit; Bacillus subtilis; Paenibacillus; Pectins; Carboxylic Ester Hydrolases
PubMed: 38795624
DOI: 10.1016/j.foodchem.2024.139746 -
Plants (Basel, Switzerland) May 2024Wheat stripe rust is globally one of the most important diseases affecting wheat. There is an urgent need to develop environmentally safe and durable biological control...
Wheat stripe rust is globally one of the most important diseases affecting wheat. There is an urgent need to develop environmentally safe and durable biological control options to supplement the control that is achieved with breeding and fungicides. In this study, endophytic bacteria were isolated from healthy wheat through the tissue separation method. Antagonistic endophytic bacteria were screened based on the control effect of urediniospore germination and wheat stripe rust (WSR). The taxonomic status of antagonistic strains was determined based on morphological, physiological, and biochemical characteristics and molecular biological identification (16S rDNA and gene sequence analysis). Finally, the potential growth-promoting effect of different concentrations of antagonists on wheat seedlings and the biological control effect of WSR were studied. A total of 136 strains of endophytic bacteria belonging to 38 genera were isolated. was the most common bacterial genus, with 29 isolates (21%). The biological control effect of different isolates was assessed using an urediniospore germination assay. The isolate XD29-G1 of had the best performance, with 85% inhibition of spore germination during primary screening. In the deep screening, the control effect of XD29-G1 on wheat stripe rust was 60%. The antagonist XD29-G1 promoted the germination of wheat seeds and the growth of wheat seedlings at a solution dilution of 10 cfu/mL. The pot experiment results showed that different dilution concentrations of the strain had different levels of antibacterial activity against WSR, with the concentration of 10 cfu/mL having the best control effect and a control efficiency of 61.19%. XD29-G1 has better biological control potential against wheat stripe rust.
PubMed: 38794437
DOI: 10.3390/plants13101366 -
Insects May 2024Honeybee diseases are one of the most significant and most common causes of honeybee colonies' weakness and death. An early diagnosis of subclinical infections is...
Honeybee diseases are one of the most significant and most common causes of honeybee colonies' weakness and death. An early diagnosis of subclinical infections is necessary to implement precautionary and control measures. Sampling debris from hive bottom boards is simple, non-invasive, and cheap. In this study, we collected winter debris samples in apiaries located in the continental part of Croatia. We used molecular methods, PCR and qPCR, for the first time to analyze those samples. Laboratory results were compared with the health condition and strength of honeybee colonies at an apiary in spring. Our study successfully identified the presence and quantity of various pathogens, including the presence of spp. ( spp.), quintefied , Acute Bee Paralysis Virus (ABPV), Black Queen Cell Virus (BQCV), Deformed Wing Virus (DWV), and Sacbrood Virus (SBV). However, our analysis did not detect , , , and . Samples of winter debris were also examined for the presence and quantification of the mites, and their natural mite fall was observed in spring. Honeybee colonies were simultaneously infected by an average of four to six pathogens. Some observed honeybee colonies developed characteristic symptoms, while others did not survive the winter.
PubMed: 38786906
DOI: 10.3390/insects15050350 -
Food Chemistry Sep 2024Bioproduction of diverse N-acetyl chitooligosaccharides from chitin is of great value. In the study, a novel GH family 18 bifunctional chitinase gene (PsChi82) from...
Bioproduction of diverse N-acetyl chitooligosaccharides from chitin is of great value. In the study, a novel GH family 18 bifunctional chitinase gene (PsChi82) from Paenibacillus shirakamiensis was identified, expressed and biochemically characterized. PsChi82 was most active at pH 5.0, and 55 °C, and displayed remarkable pH stability with the broad pH range of 3.0-12.0. It showed high chitosanase activity of 10.6 U mg and diverse hydrolysis products of GlcNAc, (GlcNAc), GlcN-GlcNAc and (GlcN)-GlcNAc, which may facilitate comprehensively understanding of structure-function relationships of N-acetyl COSs. Three engineered variants were then expressed and characterized. Among them, PsChi82-CBM26 possessed specific activity of 25.1 U mg against colloidal chitin, which was 2.1 folds higher than that of PsChi82. The diverse N-acetyl COSs were subsequently produced by PsChi82-CBM26 with a sugar content of 23.2 g L. These excellent properties may make PsChi82-CBM26 potentially useful for N-acetyl COSs production in the food and chemical industries.
Topics: Chitinases; Oligosaccharides; Chitin; Chitosan; Paenibacillus; Bacterial Proteins; Hydrogen-Ion Concentration; Enzyme Stability; Hydrolysis; Protein Engineering
PubMed: 38781901
DOI: 10.1016/j.foodchem.2024.139675