Bacterial Strains Research Articles

Spectroscopic, anti-cancer, anti-bacterial and theoretical studies of new bivalent Schiff base complexes derived from 4-bromo-2,6-dichloroaniline

In this paper, four new mono-nuclear Ni(II), Pd(II), Pt(II) and Zn(II) complexes were prepared by using a bi-dentate Schiff base ligand, (E)-2-(((4-bromo-2,6-dichlorophenyl)imino)methyl)-5-chlorophenol (BrcOH), with bivalent ions in a methanol and distil water mixture as solvent in presence of NaOH as base. The structures of the prepared compounds were characterized by spectroscopic techniques (IR and 1H NMR), CHN analysis, and molar conductivity. The M(II) (Ni, Pd and Pt) ions are four-coordinated by a bi-dentate N2O2 donor ligand, forming square planar geometry, whereas the Zn(II) is coordinated as a tetrahedral geometry. The newly synthesized compounds, which include the Schiff base ligand and its complexes, underwent antibacterial screening against E. coli and S. aureus. The results demonstrated a remarkable and noteworthy biological activity of these compounds against these pathogenic bacterial strains. Different binding energies showed good correlation, with Pd showing the strongest binding. Small energy differences indicated high reactivity, with Ni and Pd complexes being the most reactive. Electrophilicity index exhibited electron-accepting properties, with Zn showing the highest reactivity. The dipole moments showed polarity and charge separation, with Pt having the highest polarity. We evaluated the pharmacokinetic properties (ADME) of a ligand and its metal complexes using the Swiss ADME website. The results of the in-silico prediction of physicochemical properties revealed that ten compounds in total adhered to Lipinski's rule.

Synthesis, characterization and investigation of biological activities of Schiff base and its Ni(II) complex obtained from 2-Benzoylpyridine and 3-Hydroxy-2-naphthoic hydrazide

In this paper, a new aryl hydrazone and its Nickel (II) complex were synthesized from 2-benzoylpyridine and 3-Hydroxy-2-naphthoic hydrazide. The synthesized compounds were characterized by elemental analysis, UV Vis., IR, NMR spectral studies and mass spectra. The data indicate that the metal atom is coordinated by the two ligands and that the [NiL2] complex is octahedral. The ligand is coordinated through carbonyl-O, azomethine-N, and pyridyl-N atoms. When tested against various reference bacterial strains and clinical isolates, it was discovered that the antibacterial activity of the [NiL2] complex was more effective than the ligand.

Effect of Chicken Feather Hydrolysate on Growth of Spinach through Soil Amendment Method: Unraveling A Potential Liquid Biofertilizer

The study aims to investigate the effectiveness of chicken feather hydrolysate for promoting the growth of Spinacia oleracea L., a commonly consumed leafy green vegetable. An earlier isolated and identified keratinolytic bacterial species Bacillus tropicus was utilized for the preparation of chicken feather hydrolysate through submerged fermentation. Minimal media which was supplemented with chicken feather was used for the preparation of hydrolysate. The bacterial strain degraded chicken feather within 4 days of incubation after which the feather hydrolysate was collected and tested to check plant growth promoting activity through the seed germination trials and greenhouse study. Upon characterization of feather hydrolysate, it was found that the hydrolysate was a cocktail of Nitrogen, Phosphorus and Potassium (NPK) as well as other micro elements needed for plant growth. Four different concentrations of feather hydrolysate were employed for both the seed germination and greenhouse study which ranged from 25% (v/v), 30% (v/v), 35% (v/v) and 40% (v/v) including a control group (CN) which was not supplemented with feather hydrolysate. The hydrolysate supplementation brought about plant growth in all the four test concentrations with 35% (v/v) giving the highest result of 14 cm and 27.6 mg/g for tested parameters like plumule length and total chlorophyll content, respectively. The same concentration supported maximum seed germination and highest radicle extension for the germination studies as well. This study investigates the efficacy of chicken feather hydrolysate in promoting spinach growth, elucidating its potential as a fertilizer.

Evaluation of [68Ga]Ga-DOTA-AeK as a Potential Imaging Tool for PET Imaging of Cell Wall Synthesis in Bacterial Infections

The ability of bacteria to recycle exogenous amino acid-based peptides and amino sugars for peptidoglycan biosynthesis was extensively investigated using optical imaging. In particular, fluorescent AeK–NBD was effectively utilized to study the peptidoglycan recycling pathway in Gram-negative bacteria. Based on these promising results, we were inspired to develop the radioactive AeK conjugate [68Ga]Ga-DOTA-AeK for the in vivo localization of bacterial infection using PET/CT. An easy-to-implement radiolabeling procedure for DOTA-AeK with [68Ga]GaCI3 followed by solid-phase purification was successfully established to obtain [68Ga]Ga-DOTA-AeK with a radiochemical purity of ≥95%. [68Ga]Ga-DOTA-AeK showed good stability over time with less protein binding under physiological conditions. The bacterial incorporation of [68Ga]Ga-DOTA-AeK and its fluorescent Aek-NBD analog were investigated in live and heat-killed Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Unfortunately, no conclusive in vitro intracellular uptake of [68Ga]Ga-DOTA-AeK was observed for E. coli or S. aureus live and heat-killed bacterial strains (p > 0.05). In contrast, AeK-NBD showed significantly higher intracellular incorporation in live bacteria compared to the heat-killed control (p < 0.05). Preliminary biodistribution studies of [68Ga]Ga-DOTA-AeK in a dual-model of chronic infection and inflammation revealed limited localization at the infection site with non-specific accumulation in response to inflammatory markers. Finally, our study demonstrates proof that the intracellular incorporation of AeK is necessary for successful bacteria-specific imaging using PET/CT. Therefore, Ga-68 was not a suitable radioisotope for tracing the bacterial uptake of AeK tripeptide, as it required chelation with a bulky metal chelator such as DOTA, which may have limited its active membrane transportation. An alternative for optimization is to explore diverse chemical structures of AeK that would allow for radiolabeling with 18F or 11C.

Preparation, flavor component and antioxidant activity analysis of Lactiplantibacillus plantarum NCU137 fermented rice protein

Rice protein is the main component in the byproducts of rice processing such as rice dregs and rice bran. This study aims to develop lactic acid bacteria-fermented rice protein and analyze the changes of component and bioactivity. Lactiplantibacillus plantarum NCU137 was selected as the optimum fermentation strain from sixty lactic acid bacteria strains using fermentation performance and sensory score as the criteria. NCU137 was then applied to rice protein fermentation and the process parameters were optimized by single factor and orthogonal experiments. NCU137 fermentation significantly increased the acidity, antioxidant activity, and peptide content of rice protein, and eight volatile flavor compounds were identified as characteristic aroma components as determined by SPME-GC-MS. Of them, the OAV value of 1-hexanol was up to 50.94, contributing the most to the flavor of fermented rice protein. Furthermore, the antioxidant activity and mechanism of rice protein antioxidant peptide (RPAP) on H2O2-induced Caco-2 cell damage were investigated by CCK-8 method and fluorescence microscopy. RPAP showed protective effect on cell damage in a dose-dependent manner, accompanying by reduction of oxidative components such as ROS and MDA, and increasement of antioxidant components such as SOD, CAT, and GSH-PX. The protective effect might lie in the regulation of gene transcription in Nrf2/HO-1 and apoptosis Bax/Bcl pathway, as validated by RT-qPCR assay. Shortly, the rice protein fermented by NCU137 displayed significant improvement of flavor, nutritional components, and antioxidant bioactivity. The fermentation technology provides alternative strategy for processing rice protein in rice dregs and rice bran into high-valued products.

H2O2-sensitized titania with activity under visible light and in the dark

The development of visible-light photoactive materials decomposing pollutants and removing bacteria is a frequent motivation for scientific research. However, the reliance on light to sustain the degradation process restricts the practical application of photocatalysts. In this paper, titania was sensitized with H2O2 to overcome this problemand exhibit photocatalytic and dark activity. Efficiency of degradation of standard pollutant (methylene blue) and antibacterial properties (tested on two strains of bacteria: Enterococcus faecalis and Escherichia coli) were asessed. The comprehensive effect of this material is a result of the peroxide-assisted sol-gel method, without heat treatment, which allows obtaining titanium dioxide with hydroxy and adoxygen groups on the surface and in the volume. The presence of the peroxo and superoxo groups was confirmed using Raman, IR and EPR spectroscopies. The thermal stability of the adoxygen groups was analysed by TG/DSC analysis. X-ray diffraction indicated the formation of an amorphous layered structure. The Tauc plot revealed midgap states which reduced the band gaps towards visible light. The H2O2-sensitized TiO2 was characterized by negative surface potential (pHPZC=3.2) which improved adsorption.The study provides insight for the development of self-cleaning and antibacterial surfaces.

Epibiotic Bacteria Isolated from the Non-Indigenous Species Codium fragile ssp. fragile: Identification, Characterization, and Biotechnological Potential

Due to their richness in organic substances and nutrients, seaweed (macroalgae) harbor a large number of epiphytic bacteria on their surfaces. These bacteria interact with their host in multiple complex ways, in particular, by producing chemical compounds. The released metabolites may have biological properties beneficial for applications in both industry and medicine. In this study, we assess the diversity of culturable bacterial community of the invasive alga Codium fragile ssp. fragile with the aim to identify key groups within this epiphytic community. Seaweed samples were collected from the Northern Tunisian coast. A total of fifty bacteria were isolated in pure culture. These bacterial strains were identified by amplification of the ribosomal intergenic transcribed spacer between the 16S and the 23S rRNA genes (ITS-PCR) and by 16S rRNA sequencing. Antimicrobial activity, biochemical, and antibiotic resistance profile characterization were determined for the isolates. Isolated strains were tested for their antimicrobial potential against human and fish bacterial pathogens and the yeast Candida albicans, using the in vitro drop method. About 37% of isolated strains possess antibacterial activity with a variable antimicrobial spectrum. Ba1 (closely related to Pseudoalteromonas spiralis), Ba12 (closely related to Enterococcus faecium), and Bw4 (closely related to Pseudoalteromonas sp.) exhibited strong antimicrobial activity against E. coli. The isolated strain Ba4, closely related to Serratia marcescens, demonstrated the most potent activity against pathogens. The susceptibility of these strains to 12 commonly used antibiotics was investigated. Majority of the isolates were resistant to oxacillin, cefoxitin, tobramycin, and nitrofurantoin. Ba7 and Ba10, closely related to the Vibrio anguillarum strains, had the highest multidrug resistance profiles. The enzymes most commonly produced by the isolated strains were amylase, lecithinase, and agarase. Moreover, nine isolates produced disintegration zones around their colonies on agar plates with agarolitic index, ranging from 0.60 to 2.38. This investigation highlighted that Codium fragile ssp. fragile possesses an important diversity of epiphytic bacteria on its surface that could be cultivated in high biomass and may be considered for biotechnological application and as sources of antimicrobial drugs.

Influence of surface texture: A comparative study on antibacterial activities of morphologically tailored zinc oxide

The morphology-dependent antibacterial activity of zinc oxide (ZnO) nanoparticles with three different morphologies, nanowall (NW), nanosphere (NS), and, nanorod (NR) was rigorously investigated to elucidate the influence of shape and size on their performance. Their morphological, surface, and structural characteristics were meticulously analyzed using SEM, BET, and XRD techniques. The antibacterial activity of synthesized ZnO samples was initially investigated and validated through in silico docking studies against nine bacterial strains, specifically targeting 1GCI, 2DCJ, 6KMM and 3T07, 6KVQ, 1MWT from gram-positive Bacillus sp. and Staphylococcus sp. respectively, 6N38, 6CRT, 6GRH from gram-negative E. coli. The docking simulations were performed using Autodock 4.2 software, yielding promising results characterized by negative binding energies, indicative of favorable interactions. The invitro studies were assessed against three same bacteria mentioned above using the disk diffusion method. The results demonstrated a pronounced dependency of antibacterial activity on the surface area, average crystallite size, and surface roughness of ZnO samples. ZnO (NW) exhibited markedly superior antibacterial properties. This enhanced efficacy is attributed to their higher surface area to volume ratio, smaller average crystallite size and increased surface roughness facilitating more efficient interactions with bacterial cell membranes. ZnO (NR) nanoparticles exhibited enhanced antibacterial activity despite minimal surface area.

Polar-Region Soils as Novel Reservoir of Lactic Acid Bacteria from the Genus Carnobacterium.

Polar habitats offer excellent sites to isolate unique bacterial strains due to their diverse physical, geochemical, and biological factors. We hypothesize that the unique environmental conditions of polar regions select for distinct strains of lactic acid bacteria (LAB) with novel biochemical properties. In this study, we characterized ten strains of psychrotrophic LAB isolated from hitherto poorly described sources-High Arctic and maritime Antarctic soils and soil-like materials, including ornithogenic soils, cryoconites, elephant seal colonies, and postglacial moraines. We evaluated the physiological and biochemical properties of the isolates. Based on 16S rRNA and housekeeping genes, the four LAB strains were assigned to three Carnobacterium species: C. alterfunditum, C. maltaromaticum, and C. jeotgali. The remaining strains may represent three new species of the Carnobacterium genus. All isolates were neutrophilic and halophilic psychrotrophs capable of fermenting various carbohydrates, organic acids, and alcohols. The identified metabolic properties of the isolated Carnobacterium strains suggest possible syntrophic interactions with other microorganisms in polar habitats. Some showed antimicrobial activity against food pathogens such as Listeria monocytogenes and human pathogens like Staphylococcus spp. Several isolates exhibited unique metabolic traits with potential biotechnological applications that could be more effectively exploited under less stringent technological conditions compared to thermophilic LAB strains, such as lower temperatures and reduced nutrient concentrations. Analysis of extrachromosomal genetic elements revealed 13 plasmids ranging from 4.5 to 79.5 kb in five isolates, featuring unique genetic structures and high levels of previously uncharacterized genes. This work is the first comprehensive study of the biochemical properties of both known and new Carnobacterium species and enhances our understanding of bacterial communities in harsh and highly selective polar soil ecosystems.

Combined bioprocess for fermentative hydrogen production from food waste: A review

Bio hydrogen is a cheaper, sustainable and safer source to produce fuel comparable to energy obtained from fossil fuels. There are many experimental methods to produce bio hydrogen using food wastes as substrates that are acted upon by specific bacterial and fungal strains. Some of the methods include batch-dark fermentation, solid-state dark fermentation, dark-anaerobic hydrogen fermentation and integrated light-dark fermentation. Different food wastes are used in these fermentation processes such as kitchen food waste, potatoes peels, sugary waste water, fish, meats, grains, cassava residues, corn pulp and starchy solution etc. These food wastes are rich source of main raw materials that are required for bio hydrogen production such as cellulose, carbohydrates, fats, proteins, lipids, starch, phosphorus, volatile solids, Published experimental and research approaches revealed that the use of mixed dark-photo fermentative bacterial consortium in flat photo bioreactors and fermenters resulted in higher yield. Combined dark-photo fermentation is an advanced and promising strategy for increasing overall yield of bio hydrogen.

The Vehicle of Administration and Prandial State May Reduce the Spectrum of Oral Broad-Spectrum Antibiotics (Oxytetracycline, Fosfomycin and Amoxicillin) Administered to Piglets: A Pharmacokinetic/Pharmacodynamic Approach.

The objective of this study was to assess the impact of the vehicle of administration and the prandial state of post weaning piglets on the indices of therapeutic efficacy for different broad-spectrum antibiotic/pathogen combinations. Pharmacokinetic data were retrieved from previous studies, in which we orally administered oxytetracycline (OTC), fosfomycin (FOS), or amoxicillin (AMX) according to the following treatments: dissolved in soft water to fasted or non-fasted piglets, dissolved in hard water to fasted or non-fasted piglets, and mixed with feed. Minimum inhibitory concentration (MIC) values for susceptible strains of bacteria causing swine diseases were obtained from the database of European Committee on Antimicrobial Susceptibility Testing (EUCAST) for each antibiotic. Pharmacokinetic/pharmacodynamic (PK/PD) indices of therapeutic efficacy-drug exposure over the dosing interval (fAUC/MIC) for OTC and FOS; time that free drug concentration remains above MIC (%fT>MIC) for AMX-were calculated for each antibiotic/pathogen combination under each treatment. After all OTC and in-feed FOS and AMX treatments, the indices of therapeutic efficacy were below the target value for all the study microorganisms. When FOS or AMX were delivered dissolved in soft or hard water, the indices were above the target value over which therapeutic efficacy would be expected for Escherichia coli treated with FOS and, Glaesserella parasuis, Pasteurella multocida, and Actinobacillus pleuropneumoniae treated with AMX. The prandial state of piglets showed no influence on the indices of therapeutic efficacy. Pharmacokinetic profiles of broad-spectrum antibiotics, specifically the ability to achieve target concentrations, may be largely reduced due to drug interactions with components present in feed or water resulting in a discrepancy with PK/PD principles of prudent and responsible use of antibiotics.

Evaluation of physiochemical and in-vitro characteristics of Ixora Coccinea mediated Co3O4 nanoparticles for photocatalytic degradation of toxic textile dye effluents

Discharging colored wastewater from the textile industry into water bodies disrupts the natural ecosystem and reduces the productivity of aquatic life. It is challenging to degrade complex dye molecules, including pathogens and bacteria. This research article deals with the photocatalytic activity of cobalt oxide nanoparticles mediated Ixora coccinea plant extract for industry effluent treatment applications. The green synthesized nanoparticles were found to have high crystallinity and purity, cubic crystal structure, and spherical morphology with 21.5 nm crystallite size. Further, the biological properties, such as antibacterial, antioxidant, and bacterial growth inhibition activity, were evaluated. With 88 % and 83 % bacterial growth inhibition, the antibacterial activity showed a maximum bacterial zone inhibition of 31 ± 0.4 mm for positive and 29 ± 0.3 mm for harmful bacterial strains. Then, the level of scavenging free radicals measured about 93.87 %. The photocatalytic activity was evaluated against the textile dyes under direct sunlight irradiation. The maximum dye degradation was achieved for Alizarin red (85.2 %), Crystal violet (90.7 %), Reactive black (94.5 %), and Rhodamine B (96.4 %) dyes at the end of 90 min of irradiation. Moreover, this research paper introduces a method for creating cobalt nanoparticles using natural and sustainable approaches. These nanoparticles have potential in several fields, such as medicine, catalysis, and water remediation.

Investigation of the cytotoxic and antimicrobial properties of new quinoline peptide conjugates

Background: Cancer is one of the most important health problems causing deaths in Turkey and the world. Nowadays, many treatment methods such as radiotherapy and chemotherapy are applied in cancer patients. Quinoline and its derivatives, which belong to heterocyclic compounds, have many biological activities for drug development. Quinoline compounds play a crucial role in the development of antitumor drugs due to their anticancer activity. Materials and Methods: In this study, the cytotoxic effects of synthesized seven different quinoline derivatives on lung cancer (A549) and healthy lung epithelial cell (BEAS2B), liver cancer (Hep 3B), and endothelial cell (HUVEC) were determined. Different concentrations were applied and IC50 values were calculated at different time courses. The antimicrobial activites of the compounds were also determined. Results: The IC50 values of compound 2 on the A549 cell line were determined to be 10.48 μg/mL, 9.738 μg/mL, and 10.14 μg/mL. IC50 values of compound 6 on the same cell line were determined to be 7.307 µg/mL, 9.888 µg/mL, 10.63 µg/mL. Conclusions: Compounds 2 and 6 had a cytotoxic effect on the BEAS2B cell line. The antimicrobial activity of the compounds was determined by the minimum inhibition concentration method on different strains of bacteria and yeast. The compounds showed no antimicrobial activity on bacteria and yeast.

Construction of artificial microbial consortia for efficient degradation of chicken feathers and optimization of degradation conditions.

Microbes within a consortium exhibit a synergistic interaction, enhancing their collective capacity to perform functions more effectively than a single species, especially in the degradation of keratin-rich substrates. To achieve a more stable and efficient breakdown of chicken feathers, a comprehensive screening of over 9,000 microbial strains was undertaken. This meticulous selection process identified strains with the capability to degrade keratin effectively. Subsequently, antagonistic tests were conducted to isolate strains of fungi and bacteria that were non-antagonistic, which were then used to form the artificial microbial consortia. The optimal fermentation conditions for the keratinophilic microbial consortia were determined through the optimization of response surface methodology. The results revealed that 11 microbial strains-comprising of 4 fungi and 7 bacteria-were particularly proficient in degrading chicken feathers. The artificially constructed microbial consortia (AMC) comprised two bacterial strains and one fungal strain. The optimal conditions for feathers degradation were identified as a 10g/L concentration of chicken feathers, a 2.6% microbial inoculation volume and a fermentation fluid pH of 9. Under these conditions, the degradation rate for chicken feathers reached a significant 74.02%, representing an 11.45% increase over the pre-optimization rate. The AMC developed in this study demonstrates the potential for efficient and economical process of livestock and poultry feathers. It provides innovative insights and a theoretical foundation for tackling the challenging degradation of keratin-rich materials. Furthermore, this research lays the groundwork for the separation and purification of keratins, as well as the development of novel proteases, which could have profound implications for a range of applications.

Environmental Influence on Bacterial Lipid Composition: Insights from Pathogenic and Probiotic Strains.

The lipid composition of bacterial membranes is pivotal in regulating bacterial physiology, pathogenicity, and interactions with hosts. This study presents a comprehensive analysis of bacterial membrane lipid profiles across diverse Gram-positive and Gram-negative species. Utilizing matrix-assisted laser desorption/ionization (MALDI) in conjunction with advanced chemometric tools, we investigate the influence of environmental factors, isolation sources, and host metabolism on bacterial lipid profiles. Our findings unveil significant variations in lipid composition attributed to factors such as carbon/energy availability and exposure to chemicals, including antibiotics. Moreover, we identify distinct lipidomic signatures associated with pathogenic and probiotic bacterial strains, shedding light on their functional properties and metabolic pathways. Notably, bacterial strains isolated from clinical samples exhibit unique lipid profiles influenced by host metabolic dysregulation, particularly evident in conditions such as diabetic foot infections. These results deepen our understanding of the intricate mechanisms governing bacterial membrane lipid biology and hold promise for informing the development of innovative therapeutic and biotechnological strategies.

Synthesis, anti-microbial evaluation, and in silico studies of novel quinoline-isoxazole hybrids

A series of novel quinoline-isoxazole hybrids 6a–o has been synthesized via multistep synthetic approach involving hetero Diels-alder reaction strategy. The target compounds were obtained in good yield, using low-cost readily available starting materials using simple reaction conditions. The newly synthesized compounds were confirmed using 1H NMR,13C NMR, and Mass spectroscopic analysis techniques. Further, compounds 6a–o were subjected to in vitro antimicrobial screening against various bacterial and fungal strains, such as Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Salmonella typhi, Aspergillus niger, and Candida albicans. Among these, compounds 6i, 6j, and 6 l were found most active having equally potent compared to standard drug Ampicillin and Gentamycin. Moreover, in silico studies of 6a–o with E. coli DNA gyrase through molecular docking and MD simulations showed excellent binding properties of these derivatives with protein site.

Effect of Fermented Soy Beverage on Equol Production by Fecal Microbiota.

Soy consumption is associated with health benefits, mainly linked to the ability of the intestinal microbiota to metabolize the glycosylated isoflavones into more bioactive compounds, such as equol. Because Bifidobacterium pseudocatenulatum INIA P815 is able to efficiently deglycosylate daidzin into daidzein, the aim of this work was to confirm the influence of soy beverages fermented by B. pseudocatenulatum INIA P815 for enhancing equol production by fecal microbiota. Firstly, fecal samples from 17 participants were characterized in vitro, and we observed that 35.3% of them were able to produce equol from daidzein. In addition, the kinetics of equol production and degradation by fecal microbiota were evaluated, determining that 30-85% of equol is degraded after 24 h of incubation. Finally, the influence of fermented soy beverage on improving the production of equol by selected equol-producing fecal samples and by the equol-producing strain Slackia isoflavoniconvertens was analyzed through a colonic model. Fermented soy beverage enhanced the equol production from S. isoflavoniconvertens as well as the fecal samples whose microbiota showed high rates of equol degradation. The results obtained confirm that the fermentation of soy beverages with selected bacterial strains improves the functional properties of these beverages in terms of isoflavone metabolism and equol production.

Genomic insights into organic acid production and plant growth promotion by different species of phosphate-solubilizing bacteria.

Bacteria can solubilize phosphorus (P) through the secretion of low-molecular-weight organic acids and acidification. However, the genes involved in the production of these organic acids are poorly understood. The objectives of this study were to verify the calcium phosphate solubilization and the production of low-molecular-weight organic acids by diverse genera of phosphate solubilizing bacterial strains (PSBS); to identify the genes related to the synthesis of the organic acids in the genomes of these strains and; to evaluate growth and nutrient accumulation of maize plants inoculated with PSBS and fertilized with Bayóvar rock phosphate. Genomic DNA was extracted for strain identification and annotation of genes related to the organic acids production. A greenhouse experiment was performed with five strains plus 150mg dm- 3 P2O5 as Bayóvar rock phosphate (BRP) to assess phosphate solubilization contribution to maize growth and nutrition. Paraburkholderia fungorum UFLA 04-21 and Pseudomonas anuradhapurensis UFPI B5-8A solubilized over 60% of Ca phosphate and produced high amounts of citric/maleic and gluconic acids in vitro, respectively. Eleven organic acids were identified in total, although not all strains produced all acids. Besides, enzymes related to the organic acids production were found in all bacterial genomes. Plants inoculated with strains UFPI B5-6 (Enterobacter bugandensis), UFPI B5-8A, and UFLA 03-10 (Paenibacillus peoriae) accumulated more biomass than the plants fertilized with BRP only. Strains UFLA 03-10 and UFPI B5-8A increased the accumulation of most macronutrients, including P. Collectively, the results show that PSBS can increase maize growth and nutrient accumulation based on Bayóvar rock phosphate fertilization.

Diagnosis and mitigation of the systemic impact of genome reduction in Escherichia coli DGF-298.

Genomic streamlining can be employed in model organisms to reduce complexity and enhance strain predictability. One of the most striking examples is the bacterial strain Escherichia coli DGF-298, notable for having over one-third of its genome deleted. However, such extensive genome modifications raise the question of how similar this simplified cell remains when compared with its parent, and what are the possible unintended consequences of this simplification. In this study, we used metabolic modeling along with iModulon-based transcriptomic analysis in different growth conditions to assess the impact of genome reduction on metabolism and gene regulation. We observed little impact of genomic reduction on the regulatory network of E. coli DGF-298 and identified a potential metabolic bottleneck leading to the constitutive activity of the SoxS iModulon. We then leveraged the model's predictions to successfully restore SoxS activity to the basal level.

Highly Specific Polyphenolic Colloids as Alternatives to Antimicrobials in Livestock Production.

The dispersion of antibiotics in livestock farming represents a health concern worldwide, contributing to the spread of antimicrobial-resistant bacteria through animals, the environment, and humans. Phenolic compounds could be alternatives to antibiotics, once drawbacks such as their low water solubility, bioavailability, and reduced stability are overcome. Although nano- or micro-sized formulations could counter these shortcomings, they do not represent cost-effective options. In this study, three phenolic compounds, obtained from wood-processing manufacturers, were characterized, revealing suitable features such as their antioxidant activity, size, and chemical and colloidal stability for in-field applications. The minimum inhibitory concentration (MIC) of these colloidal suspensions was measured against six bacterial strains isolated from livestock. These particles showed different inhibition behaviors: Colloidal chestnut was effective against one of the most threatening antibiotic-resistant pathogens, i.e., S. aureus, but ineffective toward E. coli. Instead, colloidal pine showed a weak effect on S. aureus but specificity toward E. coli. The present proof-of-concept points at colloidal polyphenols as valuable alternatives for antimicrobial substitutes in the livestock context.