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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 -
Tropical Medicine and Infectious Disease Jun 2022Methicillin-resistant (MRSA) is a severe threat to public health globally. The development of novel agents has encountered the repeated mechanism of drug resistance....
Methicillin-resistant (MRSA) is a severe threat to public health globally. The development of novel agents has encountered the repeated mechanism of drug resistance. This study aimed to investigate an anti-MRSA substance isolated from a promising soil bacterium. The result showed that an isolate (WUL10) was in the genus. The minimum inhibitory concentration (MIC) of the purified substance was 1 µg/mL against TISTR 517 and MRSA strains. This substance showed the bactericidal effect at the concentration of 1-2 µg/mL against these bacterial indicators. The activity of the substance retained more than 95% when encountering high temperatures and a wide range of pH, but it was sensitive to proteolytic enzymes and SDS. It was identified as a novel antimicrobial peptide (KVLVKYLGGLLKLAALMV-COOH) with the predicted structure of α-helix. The substance could rupture the cell wall of the tested pathogen. MIC and MBC of the synthesized peptide were 16 and 64 µg/mL, respectively. The difference in the activity between the isolated and synthetic peptides might be from the synergistic effects of other AMPs in the purified substance. This novel AMP would provide an advantage for further development of anti-MRSA substances to manage the situation of antibiotic resistance.
PubMed: 35736972
DOI: 10.3390/tropicalmed7060093 -
PeerJ 2023Methicillin-resistant (MRSA) is listed as a highly prioritized pathogen by the World Health Organization (WHO) to search for effective antimicrobial agents. Previously,...
BACKGROUND
Methicillin-resistant (MRSA) is listed as a highly prioritized pathogen by the World Health Organization (WHO) to search for effective antimicrobial agents. Previously, we isolated a soil sp. strain SPR19 from a botanical garden, which showed anti-MRSA activity. However, the active substances were still unknown.
METHODS
The cell-free supernatant of this bacterium was subjected to salt precipitation, cation exchange, and reversed-phase chromatography. The antimicrobial activity of pure substances was determined by broth microdilution assay. The peptide sequences and secondary structures were characterized by tandem mass spectroscopy and circular dichroism (CD), respectively. The most active anti-MRSA peptide underwent a stability study, and its mechanism was determined through scanning electron microscopy, cell permeability assay, time-killing kinetics, and biofilm inhibition and eradication. Hemolysis was used to evaluate the peptide toxicity.
RESULTS
The pure substances (BrSPR19-P1 to BrSPR19-P5) were identified as new peptides. Their minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) against and MRSA isolates ranged from 2.00 to 32.00 and 2.00 to 64.00 µg/mL, respectively. The sequence analysis of anti-MRSA peptides revealed a length ranging from 12 to 16 residues accompanied by an amphipathic structure. The physicochemical properties of peptides were predicted such as pI (4.25 to 10.18), net charge at pH 7.4 (-3 to +4), and hydrophobicity (0.12 to 0.96). The CD spectra revealed that all peptides in the water mainly contained random coil structures. The increased proportion of α-helix structure was observed in P2-P5 when incubated with SDS. P2 (NH-MFLVVKVLKYVV-COOH) showed the highest antimicrobial activity and high stability under stressed conditions such as temperatures up to 100 °C, solution of pH 3 to 10, and proteolytic enzymes. P2 disrupted the cell membrane and caused bacteriolysis, in which its action was dependent on the incubation time and peptide concentration. Antibiofilm activity of P2 was determined by which the half-maximal inhibition of biofilm formation was observed at 2.92 and 4.84 µg/mL for TISTR 517 and MRSA isolate 2468, respectively. Biofilm eradication of tested pathogens was found at the P2 concentration of 128 µg/mL. Furthermore, P2 hemolytic activity was less than 10% at concentrations up to 64 µg/mL, which reflected the hemolysis index thresholds of 32.
CONCLUSION
Five novel anti-MRSA peptides were identified from SPR19. P2 was the most active peptide and was demonstrated to cause membrane disruption and cell lysis. The P2 activity was dependent on the peptide concentration and exposure time. This peptide had antibiofilm activity against tested pathogens and was compatible with human erythrocytes, supporting its potential use as an anti-MRSA agent in this post-antibiotic era.
Topics: Humans; Methicillin-Resistant Staphylococcus aureus; Staphylococcus aureus; Brevibacillus; Hemolysis; Peptides; Anti-Infective Agents; Biofilms
PubMed: 37810790
DOI: 10.7717/peerj.16143 -
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 -
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 -
Cureus Sep 2020() is an aerobic gram-positive bacillus that is rarely associated with human infection. A review of multiple online databases revealed no other cases of bacteremia in...
() is an aerobic gram-positive bacillus that is rarely associated with human infection. A review of multiple online databases revealed no other cases of bacteremia in an adult involving this organism. Historically, this "canoe-shaped" microbe has been characterized as a pathogen in invertebrates, and information regarding human infection is scarce. We present a clinical vignette of what we believe to be the first reported case of bacteremia in an adult human subject.
PubMed: 33083182
DOI: 10.7759/cureus.10481 -
Scientific Reports Apr 2018Concrete is a strong and fairly inexpensive building substance, but has several disadvantages like cracking that allows corrosion, thus reducing its lifespan. To...
Concrete is a strong and fairly inexpensive building substance, but has several disadvantages like cracking that allows corrosion, thus reducing its lifespan. To mitigate these complications, long-lasting microbial self-healing cement is an alternative that is eco-friendly and also actively repairs cracks. The present paper describes the detailed experimental investigation on compressive strength of cement mortars, mixed with six alkaliphilic bacteria, isolated from subsurface mica mines of high alkalinity. The experiments showed that the addition of alkaliphilic isolates at different cell concentrations (10 and 10 cells/ml) enhanced the compressive strength of cement mortar, because the rapid growth of bacteria at high alkalinity precipitates calcite crystals that lead to filling of pores and densifying the concrete mix. Thus, Bacillus subtilis (SVUNM4) showed the highest compressive strength (28.61%) of cement mortar at 10 cells/ml compared to those of other five alkaliphilic isolates (Brevibacillus sp., SVUNM15-22.1%; P. dendritiformis, SVUNM11-19.9%; B. methylotrophicus, SVUNM9-16%; B. licheniformis, SVUNM14-12.7% and S. maltophilia, SVUNM13-9.6%) and controlled cement mortar as well. This method resulted in the filling of cracks in concrete with calcite (CaCO), which was observed by scanning electron microscopy (SEM). Our results showed that the alkaliphilic bacterial isolates used in the study are effective in self-healing and repair of concrete cracks.
Topics: Alkalies; Bacillus; Bacillus subtilis; Brevibacillus; Calcium Carbonate; Compressive Strength; Construction Materials; Endospore-Forming Bacteria; Industrial Microbiology; Microscopy, Electron, Scanning; Paenibacillus; Stenotrophomonas
PubMed: 29691456
DOI: 10.1038/s41598-018-24730-3 -
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 -
Frontiers in Nutrition 2022Probiotics are a potential preventive strategy for obesity. However, with discrete efficacy and limited species of probiotics, there is a demand for novel strains with...
SCOPE
Probiotics are a potential preventive strategy for obesity. However, with discrete efficacy and limited species of probiotics, there is a demand for novel strains with excellent anti-obesity properties. This study aimed to investigate the effects of Brevibacillus laterosporus BL1 on preventing obesity in high-fat diet (HFD)-fed mice.
METHODS AND RESULTS
C57BL/6 male mice were randomly assigned to four groups ( = 10) and fed a control diet, HFD, HFD plus BL1, and HFD plus supernatant of BL1, respectively for 8 weeks. The results showed that prophylactic BL1 treatment reduced body weight gain by 41.26% in comparison to the HFD group, and this difference was accompanied by a reduction in body fat mass and the weight of inguinal white adipose tissues and epididymal white adipose tissue (-33.39%, -39.07%, and -43.75%, respectively). Moreover, the BL1-mediated improvements in lipid profile, insulin resistance, and chronic inflammation were associated with the regulation of gene expression related to lipid metabolism and enhancement of brown adipose tissue thermogenesis. Particularly, BL1 intervention significantly improved HFD-induced gut flora dysbiosis, as evidenced by a reverse in the relative abundance of Bacillota and Bacteroidota, as well as an increase in the relative abundance of bacteria that produce short-chain fatty acids (SCFAs), which in turn increased SCFAs levels.
CONCLUSION
Our findings found for the first time that BL1 may be a promising probiotic for prevention of obesity associated with the regulation of gut microbiota.
PubMed: 36505236
DOI: 10.3389/fnut.2022.1050025