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3 Biotech May 2021The rhizosphere microbial community is important for plant health and is shaped by numerous environmental factors. This study aimed to unravel the effects of a...
UNLABELLED
The rhizosphere microbial community is important for plant health and is shaped by numerous environmental factors. This study aimed to unravel the effects of a pesticide/fertilizer mixture on the soil rhizosphere microbiome of field-grown sugarcane. A field trial on sugarcane was conducted in Zhanjian City, Guangdong Province, China, and soil samples from the rhizosphere were collected after clothianidin pesticide and/or organic fertilizer treatments. The effects of pesticide and/or organic fertilizer treatments on the composition, diversity, and predictive function of the rhizosphere microbial communities were examined using 16S rRNA gene and ITS1 amplicon sequencing. Compared with the controls (no pesticide or fertilizer used), the microbial community that resulted from treatment with the pesticide/fertilizer mixture (SPF) had a higher relative bacterial diversity and fungal richness, and contributed more beneficial functions to sugarcane, including xenobiotics biodegradation and metabolism of amino acids. The bacterial and fungal compositions at various taxonomic levels were not significantly different in SPF and SP (pesticide only) treatments compared to treatments without the pesticide, suggesting that the clothianidin addition did not cause a detrimental impact on the soil microbiome. Moreover, five bacterial genera, including , , , , and , were significantly more abundant in the SPF and SP treatments, which could be associated with the pesticide addition. With the addition of organic fertilizers in SPF, the abundances of some soil-beneficial bacteria , , and were highly increased. Our study provides insights into the interactions between the rhizosphere soil microbiome and pesticide-fertilizer integration, which may help improve the application of pesticide-fertilizer to sugarcane fields.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s13205-021-02770-3.
PubMed: 33927998
DOI: 10.1007/s13205-021-02770-3 -
Frontiers in Microbiology 2023Changes in the soil environment in the root zone will affect the growth, development and resistance of plants. The mechanism underlying the effect of drought and flood...
Changes in the soil environment in the root zone will affect the growth, development and resistance of plants. The mechanism underlying the effect of drought and flood stress on rhizosphere bacterial diversity, soil metabolites and soil enzyme activity is not clear and needs further study. To analyze the dynamic changes in bacteria, metabolites and enzyme activities in the rhizosphere soil of maize under different drought-flood abrupt alternation (DFAA) stresses, the barrel test method was used to set up the 'sporadic light rain' to flooding (referring to trace rainfall to heavy rain) (DFAA1) group, 'continuous drought' to flooding (DFAA2) group and normal irrigation (CK) group from the jointing to the tassel flowering stage of maize. The results showed that Actinobacteria was the most dominant phylum in the two DFAA groups during the drought period and the rewatering period, and Proteobacteria was the most dominant phylum during the flooding period and the harvest period. The alpha diversity index of rhizosphere bacteria in the DFAA2 group during the flooding period was significantly lower than that in other stages, and the relative abundance of Chloroflexi was higher. The correlation analysis between the differential genera and soil metabolites of the two DFAA groups showed that the relative abundance of in the DFAA1 group was higher during the drought period, and it was significantly positively correlated with the bioactive lipid metabolites. The differential bacterium was enriched in the DFAA2 group during the flooding period and were strongly correlated with biogenic amine metabolites. The relative abundances of , and in the DFAA2 group were higher compared with DFAA1 group from rewatering to harvest and were significantly positively correlated with hydrocarbon compounds and steroid hormone metabolites. The acid phosphatase activity of the DFAA1 group was significantly higher than that of the DFAA2 group during the flooding period. The study suggests that there is a yield compensation phenomenon in the conversion of 'continuous drought' to flooding compared with 'sporadic light rain', which is related to the improvement in the flooding tolerance of maize by the dominant bacteria Chloroflexi, bacterium SJA-15 and biogenic amine metabolites. These rhizosphere bacteria and soil metabolites may have the potential function of helping plants adapt to the DFAA environment. The study revealed the response of the maize rhizosphere soil environment to DFAA stress and provided new ideas for exploring the potential mechanism of crop yield compensation under DFAA.
PubMed: 38170081
DOI: 10.3389/fmicb.2023.1295376 -
Microorganisms Mar 2024() is widely distributed in nature and demonstrates significant potential for applications in biological control, environmental protection, agricultural production, and... (Review)
Review
() is widely distributed in nature and demonstrates significant potential for applications in biological control, environmental protection, agricultural production, and clinical medicine. This review provides a comprehensive overview of the applications of in crop cultivation and animal feeding, as well as an examination of the antimicrobial peptides produced by and their antibacterial mechanisms. enhances crop cultivation by secreting hydrolases to improve nutrient absorption capabilities, synthesizing hormones to promote crop growth, and producing proteins to inhibit the reproduction of harmful organisms. has been used to improve animal production by regulating the structure of the intestinal microbiota and inhibiting the growth of pathogenic bacteria through the secretion of various antimicrobial peptides. The bactericidal activity of Brevilaterins secreted by is attributed to their ability to bind to lipopolysaccharide/lipid II molecules on the cell membrane, thereby altering permeability. Brevilaterins also inhibit bacterial reproduction by affecting relevant gene pathways in the cell membranes of pathogenic bacteria. These pathways include ATP synthesis, peptidoglycan biosynthesis, membrane transport, and cellular metabolism. In conclusion, exhibits substantial potential as a probiotic activity in crop and animal production. However, applications of in animal production could be improved, necessitating further research to elucidate the underlying probiotic mechanisms.
PubMed: 38543615
DOI: 10.3390/microorganisms12030564 -
Microbial Cell Factories Jan 2022The biosynthetic pathways for the fungal polyketides bikaverin and bostrycoidin, from Fusarium verticillioides and Fusarium solani respectively, were reconstructed and...
The biosynthetic pathways for the fungal polyketides bikaverin and bostrycoidin, from Fusarium verticillioides and Fusarium solani respectively, were reconstructed and heterologously expressed in S. cerevisiae alongside seven different phosphopantetheinyl transferases (PPTases) from a variety of origins spanning bacterial, yeast and fungal origins. In order to gauge the efficiency of the interaction between the ACP-domains of the polyketide synthases (PKS) and PPTases, each were co-expressed individually and the resulting production of target polyketides were determined after 48 h of growth. In co-expression with both biosynthetic pathways, the PPTase from Fusarium verticillioides (FvPPT1) proved most efficient at producing both bikaverin and bostrycoidin, at 1.4 mg/L and 5.9 mg/L respectively. Furthermore, the remaining PPTases showed the ability to interact with both PKS's, except for a single PKS-PPTase combination. The results indicate that it is possible to boost the production of a target polyketide, simply by utilizing a more optimal PPTase partner, instead of the commonly used PPTases; NpgA, Gsp and Sfp, from Aspergillus nidulans, Brevibacillus brevis and Bacillus subtilis respectively.
Topics: Bacterial Proteins; Biosynthetic Pathways; Cloning, Molecular; Fusarium; Isoquinolines; Models, Molecular; Polyketide Synthases; Protein Domains; Protein Structure, Tertiary; Saccharomyces cerevisiae; Transferases (Other Substituted Phosphate Groups); Xanthones
PubMed: 35012550
DOI: 10.1186/s12934-021-01734-9 -
Analysis of Bacteriohopanoids from Thermophilic Bacteria by Liquid Chromatography-Mass Spectrometry.Microorganisms Sep 2021: Hopanoids modify plasma membrane properties in bacteria and are often compared to sterols that modulate membrane fluidity in eukaryotes. In some microorganisms, they...
: Hopanoids modify plasma membrane properties in bacteria and are often compared to sterols that modulate membrane fluidity in eukaryotes. In some microorganisms, they can also allow adaptations to extreme environments. : Hopanoids were identified by liquid chromatography-mass spectrometry in fourteen strains of thermophilic bacteria belonging to five genera, i.e., , and . The bacteria were cultivated at temperatures from 42 to 70 °C. : Regardless of the source of origin, the strains have the same tendency to adapt the hopanoid content depending on the cultivation temperature. In the case of aminopentol, its content increases; aminotetrol does not show a significant change; and in the case of aminotriol the content decreases by almost a third. The content of bacteriohopanetetrol and bacteriohopanetetrol glycoside decreases with increasing temperature, while in the case of adenosylhopane the opposite trend was found. : Changes in hopanoid content can be explained by increased biosynthesis, where adenosylhopane is the first intermediate in the biosynthesis of the hopanoid side chain.
PubMed: 34683383
DOI: 10.3390/microorganisms9102062 -
Frontiers in Microbiology 2021Biofuel derived from halophytic biomass is getting attention owing to the concerns of energy versus food crisis. The disadvantages associated with edible bioenergy...
Biofuel derived from halophytic biomass is getting attention owing to the concerns of energy versus food crisis. The disadvantages associated with edible bioenergy resources necessitate the need to explore new feedstocks for sustainable biofuel production. In this study, biomass from locally available abundant halophytes (, , , and ) was screened for saccharification by an enzyme cocktail composed of cellulase, xylanase, and pectinase from UE10 and UE27, UE25, UE1, and MH 1. Two types of pretreatment, i.e., with dilute acid and freeze-thaw, were independently applied to the halophytic biomass. Saccharification of acid-pretreated biomass yielded maximum reducing sugars (9 mg g) as compared to other plants. Thus, the factors (temperature, pH, substrate concentration, and enzyme units) affecting its saccharification were optimized using central composite design. This statistical model predicted 49.8 mg g of reducing sugars that was comparable to the experimental value (40 mg g). Scanning electron microscopy and Fourier-transform infrared spectroscopy showed significant structural changes after pretreatment and saccharification. Therefore, halophytes growing in saline, arid, and semi-arid regions can be promising alternative sources for bioenergy production.
PubMed: 34616380
DOI: 10.3389/fmicb.2021.714940 -
Applied and Environmental Microbiology Nov 2020Nonribosomal peptides (NRPs) are a class of secondary metabolites usually produced by microorganisms. They are of paramount importance in different applications,...
Nonribosomal peptides (NRPs) are a class of secondary metabolites usually produced by microorganisms. They are of paramount importance in different applications, including biocontrol and pharmacy. spp. are a rich source of NRPs yet have received little attention. In this study, we characterize four novel bogorol variants (bogorols I to L, cationic linear lipopeptides) and four succilins (succilins I to L, containing a succinyl group that is attached to the Orn/Lys in bogorols I to L) from the biocontrol strain MG64. Further investigation revealed that the bogorol family of peptides employs an adenylation pathway for lipoinitiation, different from the usual pattern, which is based on an external ligase and coenzyme A. Moreover, the formation of valinol was proven to be mediated by a terminal reductase domain and a reductase encoded by the gene. Furthermore, succinylation, which is a novel type of modification in the family of bogorols, was discovered. Its occurrence requires a high concentration of the substrate (bogorols), but its responsible enzyme remains unknown. Bogorols display potent activity against both Gram-positive and Gram-negative bacteria. Investigation of their mode of action reveals that bogorols form pores in the cell membrane of both Gram-positive and Gram-negative bacteria. The combination of bogorols and relacidines, another class of NRPs produced by MG64, displays a synergistic effect on different pathogens, suggesting the great potential of both peptides as well as their producer MG64 for broad applications. Our study provides a further understanding of the bogorol family of peptides as well as their applications. NRPs form a class of secondary metabolites with biocontrol and pharmaceutical potential. This work describes the identification of novel bogorol variants and succinylated bogorols (namely, succilins) and further investigates their biosynthetic pathway and mode of action. Adenylation domain-mediated lipoinitiation of bogorols represents a novel pathway by which NRPs incorporate fatty acid tails. This pathway provides the possibility to engineer the lipid tail of NRPs without identifying a fatty acid coenzyme ligase, which is usually not present in the biosynthetic gene cluster. The terminal reductase domain (TD) and BogI-mediated valinol formation and their effect on the biological activity of bogorols are revealed. Succinylation, which is rarely reported in NRPs, was discovered in the bogorol family of peptides. We demonstrate that bogorols combat bacterial pathogens by forming pores in the cell membrane. We also report the synergistic effect of two natural products (relacidine B and bogorol K) produced by the same strain, which is relevant for competition for a niche.
Topics: Anti-Bacterial Agents; Brevibacillus; Lipopeptides; Microbial Sensitivity Tests
PubMed: 32978140
DOI: 10.1128/AEM.01981-20 -
Bioengineered Dec 2020This work highlights the potential of corncob biochar (CCBC) and for the decolorization of brilliant green (BG) dye from synthetically prepared contaminated wastewater....
This work highlights the potential of corncob biochar (CCBC) and for the decolorization of brilliant green (BG) dye from synthetically prepared contaminated wastewater. The CCBC was characterized by proximate, Fourier-transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and Brunauer-Emmett-Teller analysis, respectively. Different parameters affecting the adsorption process were evaluated. The experimental results were analyzed by the Langmuir and Freundlich isotherm models. Kinetic results were examined by different models; pseudo-second-order model has shown the best fit to the experimental data. Anew positive values of (172.58 kJ/mol) and (569.97 J/K/mol) in the temperature range of 303-318 revealed that the adsorption process was spontaneous and endothermic. The present investigation showed that the bacteria immobilized with CCBC showed better BG dye degradation. The kinetic parameters, , and μ were found to be 0.5 per day, 39.4 mg/day, and 0.012 L/mg/day using Monod model, respectively. The adsorbent with bacteria showed good potential for the removal of cationic BG dye and can be considered for the remediation of industrial effluent.
Topics: Brevibacillus; Charcoal; Kinetics; Waste Disposal, Fluid; Wastewater; X-Ray Diffraction
PubMed: 32631112
DOI: 10.1080/21655979.2020.1788353 -
Molecules (Basel, Switzerland) Dec 2022Methicillin-resistant (MRSA) is listed as a high-priority pathogen because its infection is associated with a high mortality rate. It is urgent to search for new agents...
Methicillin-resistant (MRSA) is listed as a high-priority pathogen because its infection is associated with a high mortality rate. It is urgent to search for new agents to treat such an infection. Our previous study isolated a soil bacterium ( sp. SPR-20), showing the highest antimicrobial activity against TISTR 517 and MRSA strains. The present study aimed to purify and characterize anti-MRSA substances produced by SPR-20. The result showed that five active substances (P1-P5) were found, and they were identified by LC-MS/MS that provided the peptide sequences of 14-15 residues. Circular dichroism showed that all peptides contained β-strand and disordered conformations as the major secondary structures. Only P1-P4 adopted more α-helix conformations when incubated with 50 mM SDS. These anti-MRSA peptides could inhibit and MRSA in concentrations of 2-32 μg/mL. P1 (NH-VVVNVLVKVLPPPVV-COOH) had the highest activity and was identified as a novel antimicrobial peptide (AMP). The stability study revealed that P1 was stable in response to temperature, proteolytic enzymes, surfactant, and pH. The electron micrograph showed that P1 induced bacterial membrane damage when treated at 1× MIC in the first hour of incubation. The killing kinetics of P1 was dependent on concentration and time. Mechanisms of P1 on tested pathogens involved membrane permeability, leakage of genetic material, and cell lysis. The P1 peptide at a concentration up to 32 μg/mL showed hemolysis of less than 10%, supporting its safety for human erythrocytes. This study provides promising anti-MRSA peptides that might be developed for effective antibiotics in the post-antibiotic era.
Topics: Humans; Methicillin-Resistant Staphylococcus aureus; Staphylococcus aureus; Microbial Sensitivity Tests; Brevibacillus; Chromatography, Liquid; Tandem Mass Spectrometry; Anti-Bacterial Agents; Peptides
PubMed: 36500545
DOI: 10.3390/molecules27238452 -
Physiology and Molecular Biology of... May 2020L. provides an enormous range of medicinal and nutritional benefits. The significant abilities of this plant to survive in Himalayan high altitudes enticed our study to...
L. provides an enormous range of medicinal and nutritional benefits. The significant abilities of this plant to survive in Himalayan high altitudes enticed our study to investigate its rhizosphere. Seventeen rhizobacterial strains were isolated from the rhizospheric soil and plant root nodules, belonging to genus , , , , and , as identified by 16SrRNA sequencing. This varying bacterial population was further examined for the presence of root degrading enzymes pectinase and cellulase, which enable them to intrude the plant roots. Based on the growth and substrate utilization by these rhizobacteria on pectinase screening agar medium and Mandels and Reese agar medium, all the seventeen strains were identified as pectinase and cellulase producing rhizobacteria. The quantitative analysis by DNS method demonstrated varying enzyme activities, spot-lighting the physiological variation in the microbiome. The divergence in the enzyme activities shown by all the strains was analysed statistically, using the software ASSISTAT.
PubMed: 32377055
DOI: 10.1007/s12298-020-00778-2