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BMC Complementary Medicine and Therapies May 2024The plant roots excrete a large number of organic compounds into the soil. The rhizosphere, a thin soil zone around the roots, is a hotspot for microbial activity,...
BACKGROUND
The plant roots excrete a large number of organic compounds into the soil. The rhizosphere, a thin soil zone around the roots, is a hotspot for microbial activity, making it a crucial component of the soil ecosystem. Secondary metabolites produced by rhizospheric Sphingomonas sanguinis DM have sparked significant curiosity in investigating their possible biological impacts.
METHODS
A bacterial strain has been isolated from the rhizosphere of Datura metel. The bacterium's identification, fermentation, and working up have been outlined. The ethyl acetate fraction of the propagated culture media of Sphingomonas sanguinis DM was fractioned and purified using various chromatographic techniques. The characterization of the isolated compounds was accomplished through the utilization of various spectroscopic techniques, such as UV, MS, 1D, and 2D-NMR. Furthermore, the evaluation of their antimicrobial activity was conducted using the agar well diffusion method, while cytotoxicity was assessed using the MTT test.
RESULTS
The extract from Sphingomonas sanguinis DM provided two distinct compounds: n-dibutyl phthalic acid (1) and Bis (2-methyl heptyl) phthalate (2) within its ethyl acetate fraction. Furthermore, the 16S rRNA gene sequence of Sphingomonas sanguinis DM has been registered under the NCBI GenBank database with the accession number PP422198. The bacterial extract exhibited its effect against gram-positive bacteria, inhibiting Streptococcus mutans (12.6 ± 0.6 mm) and Staphylococcus aureus (10.6 ± 0.6 mm) compared to standard antibiotics. Conversely, compound 1 showed a considerable effect against phytopathogenic fungi such as Alternaria alternate (56.3 ± 10.6 mm) and Fusarium oxysporum (21.3 ± 1.5 mm) with a MIC value of 17.5 µg/mL. However, it was slightly active against Klebsiella pneumonia (11.0 ± 1.0 mm). Furthermore, compound 2 was the most active metabolite, having a significant antimicrobial efficacy against Rhizoctonia solani (63.6 ± 1.1 mm), Pseudomonas aeruginosa (16.7 ± 0.6 mm), and Alternaria alternate (20.3 ± 0.6 mm) with MIC value at 15 µg/mL. In addition, compound 2 exhibited the most potency against hepatocellular (HepG-2) and skin (A-431) carcinoma cell lines with IC values of 107.16 µg/mL and 111.36 µg/mL, respectively.
CONCLUSION
Sphingomonas sanguinis DM, a rhizosphere bacterium of Datura metel, was studied for its phytochemical and biological characteristics, resulting in the identification of two compounds with moderate antimicrobial and cytotoxic activities.
Topics: Sphingomonas; Rhizosphere; Datura metel; Humans; Phytochemicals; Microbial Sensitivity Tests; Plant Roots; Anti-Bacterial Agents; Secondary Metabolism
PubMed: 38796482
DOI: 10.1186/s12906-024-04482-6 -
Molecules (Basel, Switzerland) May 2024Environmental pollution stands as one of the significant global challenges we face today. Polycyclic aromatic hydrocarbons (PAHs), a class of stubborn organic...
Environmental pollution stands as one of the significant global challenges we face today. Polycyclic aromatic hydrocarbons (PAHs), a class of stubborn organic pollutants, have long been a focal point of bioremediation research. This study aims to explore the impact and mechanisms of graphene oxide (GO) on the phytoremediation effectiveness of PAHs. The results underscore the significant efficacy of GO in accelerating the degradation of PAHs. Additionally, the introduction of GO altered the diversity and community structure of endophytic bacteria within the roots, particularly those genera with potential for PAH degradation. Through LEfSe analysis and correlation studies, we identified specific symbiotic bacteria, such as , , , , , , and , which coexist and interact under the influence of GO, synergistically degrading PAHs. These bacteria may serve as key biological markers in the PAH degradation process. These findings provide new theoretical and practical foundations for the application of nanomaterials in plant-based remediation of polluted soils and showcase the immense potential of plant-microbe interactions in environmental restoration.
Topics: Graphite; Polycyclic Aromatic Hydrocarbons; Soil Pollutants; Biodegradation, Environmental; Soil Microbiology; Bacteria; Endophytes; Plant Roots; Sphingomonas; Plants; Mycobacterium; Flavobacterium; Streptomyces; Microbacterium
PubMed: 38792204
DOI: 10.3390/molecules29102342 -
Microbial Cell Factories May 2024Zymomonas mobilis is well known for its outstanding ability to produce ethanol with both high specific productivity and with high yield close to the theoretical maximum....
BACKGROUND
Zymomonas mobilis is well known for its outstanding ability to produce ethanol with both high specific productivity and with high yield close to the theoretical maximum. The key enzyme in the ethanol production pathway is the pyruvate decarboxylase (PDC) which is converting pyruvate to acetaldehyde. Since it is widely considered that its gene pdc is essential, metabolic engineering strategies aiming to produce other compounds derived from pyruvate need to find ways to reduce PDC activity.
RESULTS
Here, we present a new platform strain (sGB027) of Z. mobilis in which the native promoter of pdc was replaced with the IPTG-inducible P allowing for a controllable expression of pdc. Expression of lactate dehydrogenase from E. coli in sGB027 allowed the production of D-lactate with, to the best of our knowledge, the highest reported specific productivity of any microbial lactate producer as well as with the highest reported lactate yield for Z. mobilis so far. Additionally, by expressing the L-alanine dehydrogenase of Geobacillus stearothermophilus in sGB027 we produced L-alanine, further demonstrating the potential of sGB027 as a base for the production of compounds other than ethanol.
CONCLUSION
We demonstrated that our new platform strain can be an excellent starting point for the efficient production of various compounds derived from pyruvate with Z. mobilis and can thus enhance the establishment of this organism as a workhorse for biotechnological production processes.
Topics: Zymomonas; Pyruvate Decarboxylase; Metabolic Engineering; Ethanol; Lactic Acid; Escherichia coli; L-Lactate Dehydrogenase; Alanine; Pyruvic Acid; Fermentation
PubMed: 38773442
DOI: 10.1186/s12934-024-02419-9 -
Scientific Reports May 2024The narrow zone of soil around the plant roots with maximum microbial activity termed as rhizosphere. Rhizospheric bacteria promote the plant growth directly or...
The narrow zone of soil around the plant roots with maximum microbial activity termed as rhizosphere. Rhizospheric bacteria promote the plant growth directly or indirectly by providing the nutrients and producing antimicrobial compounds. In this study, the rhizospheric microbiota of peanut plants was characterized from different farms using an Illumina-based partial 16S rRNA gene sequencing to evaluate microbial diversity and identify the core microbiome through culture-independent (CI) approach. Further, all rhizospheric bacteria that could grow on various nutrient media were identified, and the diversity of those microbes through culture-dependent method (CD) was then directly compared with their CI counterparts. The microbial population profiles showed a significant correlation with organic carbon and concentration of phosphate, manganese, and potassium in the rhizospheric soil. Genera like Sphingomicrobium, Actinoplanes, Aureimonas _A, Chryseobacterium, members from Sphingomonadaceae, Burkholderiaceae, Pseudomonadaceae, Enterobacteriaceae family, and Bacilli class were found in the core microbiome of peanut plants. As expected, the current study demonstrated more bacterial diversity in the CI method. However, a higher number of sequence variants were exclusively present in the CD approach compared to the number of sequence variants shared between both approaches. These CD-exclusive variants belonged to organisms that are more typically found in soil. Overall, this study portrayed the changes in the rhizospheric microbiota of peanuts in different rhizospheric soil and environmental conditions and gave an idea about core microbiome of peanut plant and comparative bacterial diversity identified through both approaches.
Topics: Rhizosphere; Arachis; India; Soil Microbiology; Microbiota; RNA, Ribosomal, 16S; Metagenomics; Bacteria; Farms; Plant Roots; Phylogeny; Metagenome; Biodiversity
PubMed: 38720057
DOI: 10.1038/s41598-024-61343-5 -
AMB Express May 2024Multidrug-resistant (MDR) pathogens are a rising global health worry that imposes an urgent need for the discovery of novel antibiotics particularly those of natural...
Multidrug-resistant (MDR) pathogens are a rising global health worry that imposes an urgent need for the discovery of novel antibiotics particularly those of natural origin. In this context, we aimed to use the metagenomic nanopore sequence analysis of soil microbiota coupled with the conventional phenotypic screening and genomic analysis for identifying the antimicrobial metabolites produced by promising soil isolate(s). In this study, whole metagenome analysis of the soil sample(s) was performed using MinION™ (Oxford Nanopore Technologies). Aligning and analysis of sequences for probable secondary metabolite gene clusters were extracted and analyzed using the antiSMASH version 2 and DeepBGC. Results of the metagenomic analysis showed the most abundant taxa were Bifidobacterium, Burkholderia, and Nocardiaceae (99.21%, followed by Sphingomonadaceae (82.03%) and B. haynesii (34%). Phenotypic screening of the respective soil samples has resulted in a promising Bacillus isolate that exhibited broad-spectrum antibacterial activities against various MDR pathogens. It was identified using microscopical, cultural, and molecular methods as Bacillus (B.) haynesii isolate MZ922052. The secondary metabolite gene analysis revealed the conservation of seven biosynthetic gene clusters of antibacterial metabolites namely, siderophore lichenicidin VK21-A1/A2 (95% identity), lichenysin (100%), fengycin (53%), terpenes (100%), bacteriocin (100%), Lasso peptide (95%) and bacillibactin (53%). In conclusion, metagenomic nanopore sequence analysis of soil samples coupled with conventional screening helped identify B. haynesii isolate MZ922052 harboring seven biosynthetic gene clusters of promising antimicrobial metabolites. This is the first report for identifying the bacteriocin, lichenysin, and fengycin biosynthetic gene clusters in B. haynesii MZ922052.
PubMed: 38704474
DOI: 10.1186/s13568-024-01701-8 -
Ecotoxicology and Environmental Safety Jun 2024The success of the sodic soil reclamation using elemental S (S°) depends on the population of the native S° oxidizers. Augmenting the native flora of the sodic soils...
The success of the sodic soil reclamation using elemental S (S°) depends on the population of the native S° oxidizers. Augmenting the native flora of the sodic soils with effective S° oxidizers can enhance the success of the sodic soil reclamation. Present study reports for the first time the S° oxidation potential of the Sphingomonas olei strain 20UP7 isolated from sodic soils with pH 9.8 and EC 3.6 dS m. Inoculation with S. olei strain 20UP7 caused 13.0-24.2 % increase in S° oxidation in different sodic soils (pH 9.1-10.5). It improved the concentration of the Ca, Mg, PO and declined the HCO and total alkalinity of the soil solution. This isolate also showed appreciable P and Zn solubilization, indole acetic acid, ammonia, and titratable acidity production in the growth media. It tended to the formation of biofilm around sulphur particles. The PCR amplification with gene-specific primers showed the occurrence of soxA, soxB, and soxY genes with a single band corresponding to length of 850, 460, and 360 base pairs, respectively. The integration of the S. olei strain 20UP7 with S° caused 21.7-25.4 % increase in the rice and wheat yield compared to the soil treated with S° alone. This study concludes that the S. olei, native to high saline-sodic soils can be utilized for improving the sodicity reclamation and plant growth promotion using elemental S based formulations.
Topics: Oxidation-Reduction; Soil; Soil Microbiology; Sulfur; Sphingomonas; Hydrogen-Ion Concentration; Biofilms; Plant Development; Indoleacetic Acids; Oryza; Soil Pollutants
PubMed: 38696872
DOI: 10.1016/j.ecoenv.2024.116396 -
Emerging Infectious Diseases May 2024We report a case of Sphingobium yanoikuyae bacteremia in an 89-year-old patient in Japan. No standard antimicrobial regimen has been established for S. yanoikuyae...
We report a case of Sphingobium yanoikuyae bacteremia in an 89-year-old patient in Japan. No standard antimicrobial regimen has been established for S. yanoikuyae infections. However, ceftriaxone and ceftazidime treatments were effective in this case. Increased antimicrobial susceptibility data are needed to establish appropriate treatments for S. yanoikuyae.
Topics: Aged, 80 and over; Humans; Male; Anti-Bacterial Agents; Bacteremia; Gram-Negative Bacterial Infections; Japan; Microbial Sensitivity Tests; Sphingomonadaceae
PubMed: 38666619
DOI: 10.3201/eid3005.231514 -
Applied Microbiology and Biotechnology Apr 2024An alpha-proteobacterial strain JXJ CY 53 was isolated from the cyanosphere of Microcystis sp. FACHB-905 (MF-905) collected from Lake Dianchi, China. JXJ CY 53 was...
An alpha-proteobacterial strain JXJ CY 53 was isolated from the cyanosphere of Microcystis sp. FACHB-905 (MF-905) collected from Lake Dianchi, China. JXJ CY 53 was observed to be an aerobic, Gram-stain-negative, oval shaped, and mucus-secreting bacterium. It had Cω7c and C as the major cellular fatty acids, Q-10 as the predominant ubiquinone, and sphingoglycolipid, diphosphatidylglycerol, phosphatidylcholine, and phosphatidylmethylethanolamine as the polar lipids. The G + C content of DNA was 65.85%. The bacterium had 16S rRNA gene sequence identities of 98.9% and 98.7% with Sphingomonas panni DSM 15761 and Sphingomonas hankookensis KCTC 22579, respectively, while less than 97.4% identities with other members of the genus. Further taxonomic analysis indicated that JXJ CY 53 represented a new member of Sphingomonas, and the species epithet was proposed as Sphingomonas lacusdianchii sp. nov. (type strain JXJ CY 53 = KCTC 72813 = CGMCC 1.17657). JXJ CY 53 promoted the growth of MF-905 by providing bio-available phosphorus and nitrogen, plant hormones, vitamins, and carotenoids. It could modulate the relative abundances of nonculturable bacteria associated with MF-905 and influence the interactions of MF-905 and other bacteria isolated from the cyanobacterium, in addition to microcystin production characteristics. Meanwhile, MF-905 could provide JXJ CY 53 dissolved organic carbon for growth, and control the growth of JXJ CY 53 by secreting specific chemicals other than microcystins. Overall, these results suggest that the interactions between Microcystis and its attached bacteria are complex and dynamic, and may influence the growth characteristics of the cyanobacterium. This study provided new ideas to understand the interactions between Microcystis and its attached bacteria. KEY POINTS: • A novel bacterium (JXJCY 53 ) was isolated from the cyanosphere of Microcystis sp. FACHB-905 (MF-905) • JXJCY 53 modulated the growth and microcystin production of MF-905 • MF-905 could control the attached bacteria by specific chemicals other than microcystins (MCs).
Topics: Sphingomonas; RNA, Ribosomal, 16S; Phylogeny; China; Fatty Acids; DNA, Bacterial; Base Composition; Phospholipids; Microcystis; Lakes; Sequence Analysis, DNA; Bacterial Typing Techniques; Symbiosis; Ubiquinone
PubMed: 38661971
DOI: 10.1007/s00253-024-13081-x -
PloS One 2024A Hungarian survey of Tokaj-Mád vineyards was conducted. Shotgun metabarcoding was applied to decipher the microbial-terroir. The results of 60 soil samples showed that...
A Hungarian survey of Tokaj-Mád vineyards was conducted. Shotgun metabarcoding was applied to decipher the microbial-terroir. The results of 60 soil samples showed that there were three dominant fungal phyla, Ascomycota 66.36% ± 15.26%, Basidiomycota 18.78% ± 14.90%, Mucoromycota 11.89% ± 8.99%, representing 97% of operational taxonomic units (OTUs). Mutual interactions between microbiota diversity and soil physicochemical parameters were revealed. Principal component analysis showed descriptive clustering patterns of microbial taxonomy and resistance gene profiles in the case of the four historic vineyards (Szent Tamás, Király, Betsek, Nyúlászó). Linear discriminant analysis effect size was performed, revealing pronounced shifts in community taxonomy based on soil physicochemical properties. Twelve clades exhibited the most significant shifts (LDA > 4.0), including the phyla Verrucomicrobia, Bacteroidetes, Chloroflexi, and Rokubacteria, the classes Acidobacteria, Deltaproteobacteria, Gemmatimonadetes, and Betaproteobacteria, the order Sphingomonadales, Hypomicrobiales, as well as the family Sphingomonadaceae and the genus Sphingomonas. Three out of the four historic vineyards exhibited the highest occurrences of the bacterial genus Bradyrhizobium, known for its positive influence on plant development and physiology through the secretion of steroid phytohormones. During ripening, the taxonomical composition of the soil fungal microbiota clustered into distinct groups depending on altitude, differences that were not reflected in bacteriomes. Network analyses were performed to unravel changes in fungal interactiomes when comparing postveraison and preharvest samples. In addition to the arbuscular mycorrhiza Glomeraceae, the families Mycosphaerellacae and Rhyzopodaceae and the class Agaricomycetes were found to have important roles in maintaining soil microbial community resilience. Functional metagenomics showed that the soil Na content stimulated several of the microbiota-related agrobiogeochemical cycles, such as nitrogen and sulphur metabolism; steroid, bisphenol, toluene, dioxin and atrazine degradation and the synthesis of folate.
Topics: Humans; Soil; Wine; Microbiota; Bacteria; Ascomycota; Steroids; Soil Microbiology
PubMed: 38626236
DOI: 10.1371/journal.pone.0300563 -
PloS One 2024Assessing the microbes present on tree fruit carpospheres as the fruit enters postharvest processing could have useful applications, as these microbes could have a major...
Assessing the microbes present on tree fruit carpospheres as the fruit enters postharvest processing could have useful applications, as these microbes could have a major influence on spoilage, food safety, verification of packing process controls, or other aspects of processing. The goal of this study was to establish a baseline profile of bacterial communities associated with apple (pome fruit), peach (stone fruit), and Navel orange (citrus fruit) at harvest. We found that commercial peaches had the greatest bacterial richness followed by oranges then apples. Time of harvest significantly changed bacterial diversity in oranges and peaches, but not apples. Shifts in diversity varied by fruit type, where 70% of the variability in beta diversity on the apple carposphere was driven by the gain and loss of species (i.e., nestedness). The peach and orange carposphere bacterial community shifts were driven by nearly an even split between turnover (species replacement) and nestedness. We identified a small core microbiome for apples across and between growing seasons that included only Methylobacteriaceae and Sphingomonadaceae among the samples, while peaches had a larger core microbiome composed of five bacterial families: Bacillaceae, Geodermtophilaceae, Nocardioidaceae, Micrococcaeceae, and Trueperaceae. There was a relatively diverse core microbiome for oranges that shared all the families present on apples and peaches, except for Trueperaceae, but also included an additional nine bacterial families not shared including Oxalobacteraceae, Cytophagaceae, and Comamonadaceae. Overall, our findings illustrate the important temporal dynamics of bacterial communities found on major commercial tree fruit, but also the core bacterial families that constantly remain with both implications being important entering postharvest packing and processing.
Topics: Humans; Prunus persica; Seasons; Bacteria; Citrus sinensis; Fruit
PubMed: 38625898
DOI: 10.1371/journal.pone.0297453