Search Results (723)

Lactoferrin (LF) is an 80 kDa iron-binding glycoprotein primarily found in milk, saliva, tears, and nasal secretions. LF is well known for its antibacterial and immunomodulatory effects. However, the extraction of LF from milk is inadequate for large-scale therapeutic applications, presenting a challenge for economic mass production. Recombinant protein expression systems offer a solution to overcome this challenge and efficient production of LF. This review discusses recent progress in the translational research of LF gene transfer and biopharming, focusing on different expression systems such as bacteria, yeast, filamentous fungi, transgenic crops, and animals as well as purification methods. The optimization of expression yields, prospects for genetic engineering, and biotechnology to enhance LF production for biomedical applications are emphasized. This review systematically sourced the literature from 1987 to 2025 from leading scientific databases, including PubMed, Scopus, Web of Science, and Google Scholar. Despite ongoing debates, progress in this field indicates a viable path towards the effective use of LF in therapeutic settings. Full article

Soil degradation resulting from intensive agricultural practices, the excessive use of agrochemicals, and climate-induced stresses has significantly impaired soil fertility, disrupted microbial diversity, and reduced crop productivity. Plant growth-promoting bacteria (PGPB) represent a sustainable biological approach to restoring degraded soils by modulating plant physiology and soil function through diverse molecular mechanisms. PGPB synthesizes indole-3-acetic acid (IAA) to stimulate root development and nutrient uptake and produce ACC deaminase, which lowers ethylene accumulation under stress, mitigating growth inhibition. They also enhance nutrient availability by releasing phosphate-solubilizing enzymes and siderophores that improve iron acquisition. In parallel, PGPB activates jasmonate and salicylate pathways, priming a systemic resistance to biotic and abiotic stress. Through quorum sensing, biofilm formation, and biosynthetic gene clusters encoding antibiotics, lipopeptides, and VOCs, PGPB strengthen rhizosphere colonization and suppress pathogens. These interactions contribute to microbial community recovery, an improved soil structure, and enhanced nutrient cycling. This review synthesizes current evidence on the molecular and physiological mechanisms by which PGPB enhance soil restoration in degraded agroecosystems, highlighting their role beyond biofertilization as key agents in ecological rehabilitation. It examines advances in nutrient mobilization, stress mitigation, and signaling pathways, based on the literature retrieved from major scientific databases, focusing on studies published in the last decade. Full article

Sourdough fermentation, driven by the biochemical activity of lactic acid bacteria (LAB), presents a scientifically promising approach to addressing nutritional limitations in cereal-based staples. This review critically examines both the underlying mechanisms by which LAB enhance the nutritional profile of sourdough and the translational challenges in realizing these benefits. Key improvements explored include enhanced mineral bioavailability (e.g., up to 90% phytate reduction), improved protein digestibility, an attenuated glycemic response (GI ≈ 54 vs. ≈75 for conventional bread), and the generation of bioactive compounds. While in vitro and animal studies extensively demonstrate LAB’s potential to reshape nutrient profiles (e.g., phytate hydrolysis improving iron absorption, proteolysis releasing bioactive peptides), translating these effects into consistent human health outcomes proves complex. Significant challenges hinder this transition from laboratory to diet, including the limited bioavailability of LAB-derived metabolites, high strain variability, and sensitivity to fermentation conditions. Furthermore, interactions with the food matrix and host-specific factors, such as gut microbiota composition, contribute to inconsistent findings. This review highlights methodological gaps, particularly reliance on in vitro or animal models, and the lack of long-term, effective human trials. Although LAB hold significant promise for nutritional improvements in sourdough, translating these findings to validated human benefits necessitates continued efforts in mechanism-driven strain optimization, the standardization of fermentation processes, and rigorous human studies. Full article

Snails at hydrothermal vents rely on symbiotic bacteria for nutrition; however, the specifics of these associations in adapting to such extreme environments remain underexplored. This study investigated the community structure and metabolic potential of bacteria associated with two Indian Ocean vent snails, Chrysomallon squamiferum and Gigantopelta aegis. Using microscopic, phylogenetic, and metagenomic analyses, this study examines bacterial communities inhabiting the foot and gland tissues of these snails. G. aegis exhibited exceptionally low bacterial diversity (Shannon index 0.14–0.18), primarily Gammaproteobacteria (99.9%), including chemosynthetic sulfur-oxidizing Chromatiales using Calvin–Benson–Bassham cycle and methane-oxidizing Methylococcales in the glands. C. squamiferum hosted significantly more diverse symbionts (Shannon indices 1.32–4.60). Its black variety scales were dominated by Campylobacterota (67.01–80.98%), such as Sulfurovum, which perform sulfur/hydrogen oxidation via the reductive tricarboxylic acid cycle, with both Campylobacterota and Gammaproteobacteria prevalent in the glands. The white-scaled variety of C. squamiferum had less Campylobacterota but a higher diversity of heterotrophic bacteria, including Delta-/Alpha-Proteobacteria, Bacteroidetes, and Firmicutes (classified as Desulfobacterota, Pseudomomonadota, Bacteroidota, and Bacillota in GTDB taxonomy). In C. squamiferum, Gammaproteobacteria, including Chromatiales, Thiotrichales, and a novel order “Endothiobacterales,” were chemosynthetic, capable of oxidizing sulfur, hydrogen, or iron, and utilizing the Calvin–Benson–Bassham cycle for carbon fixation. Heterotrophic Delta- and Alpha-Proteobacteria, Bacteroidetes, and Firmicutes potentially utilize organic matter from protein, starch, collagen, amino acids, thereby contributing to the holobiont community and host nutrition accessibility. The results indicate that host species and intra-species variation, rather than the immediate habitat, might shape the symbiotic microbial communities, crucial for the snails’ adaptation to vent ecosystems. Full article

The increasing threat of antimicrobial resistance (AMR), along with the limited availability of new lead compounds in the drug development pipeline, highlights the urgent need to discover antimicrobial agents with innovative mechanisms of action. In this regard, metal complexes offer a unique opportunity to access mechanisms distinct from those of conventional antibiotics. Although iron (Fe) is an essential element for all forms of life, including pathogenic bacteria, it also poses a serious risk of cytotoxicity due to its redox activity, which can trigger the production of reactive oxygen species (ROS) via the Fenton reaction. This review highlights recent advances in the development of iron-based antimicrobial agents that harness the toxicity resulting from dysregulated iron uptake, thereby inducing bacterial cell death through oxidative stress. These findings may guide the development of effective treatments for pathogenic infections and offer new perspectives on leveraging redox chemistry of iron to combat the growing threat of global bacterial resistance. Full article

The eight new copper(II), nickel(II), zinc(II), and iron(III) coordination compounds [Cu(L)Cl]₂ (1), [Cu(L)Br]₂ (2), [Cu(L)(NO₃)]₂ (3), [Cu(phen)(L)]NO₃ (4), [Ni(HL)₂](NO₃)₂·H₂O (5), [Ni(HL)₂]Cl₂ (6), [Zn(L)₂]·0.125H₂O (7), and [Fe(L)₂]Cl (8), where HL stands for 2-benzoylpyridine 4-allylthiosemicarbazone, were synthesized and characterized. ¹H, ¹³C NMR, and FTIR spectroscopies were used for characterization of the HL thiosemicarbazone. The elemental analysis, the FTIR spectroscopy, and the study of molar electrical conductivity were used for characterization of the coordination compounds 1–8. Also, the crystal structures of HL, its salts ([H₂L]Cl; [H₂L]NO₃), and complexes 1, 3, 5, 7, and 8 were determined using single-crystal X-ray diffraction analysis. Complexes 5, 7, 8 have mononuclear structures, while copper(II) complexes 1 and 3 have a dimeric structure with the sulfur atoms of the thiosemicarbazone ligand bridging two copper atoms together. Thiosemicarbazone HL and the complexes manifest antibacterial and antifungal activities. The studied substances are more active towards Gram-negative bacteria than towards Gram-positive bacteria and fungi. Complex 1 is the most active one towards Gram-positive bacteria and C. albicans, while the introduction of 1,10-phenanthroline into the inner sphere enhances the activity towards Gram-negative bacteria. Thiosemicarbazone and complexes 6 and 7 manifest antiradical activity that exceeds the activity of Trolox. HL and complex 1 manifest antiproliferative activity towards HL-60 cancer cells which exceeds the activity of their analogs with 2-formyl-/2-acetylpyridine 4-allylthiosemicarbazone. Full article

The presence of recalcitrant organic compounds in oilfield-produced-water poses significant challenges for conventional biological treatment technologies. In this study, an Fe³⁺-augmented composite bioreactor was developed to enhance the multi-pollutant removal performance and to elucidate the associated microbial community dynamics. The Fe³⁺-augmented system achieved efficient removal of oil (99.18 ± 0.91%), suspended solids (65.81 ± 17.55%), chemical oxygen demand (48.63 ± 15.15%), and polymers (57.72 ± 14.87%). The anaerobic compartment served as the core biotreatment unit, playing a pivotal role in microbial pollutant degradation. High-throughput sequencing indicated that Fe³⁺ supplementation strengthened syntrophic interactions between iron-reducing bacteria (Trichococcus and Bacillus) and methanogenic archaea (Methanobacterium and Methanomethylovorans), thereby facilitating the biodegradation of long-chain hydrocarbons (e.g., eicosane and nonadecane). Further metabolic function analysis identified long-chain-fatty-acid CoA ligase (EC 6.2.1.3) as a key enzyme mediating the interplay between hydrocarbon degradation and nitrogen cycling. This study elucidated the ecological mechanisms governing Fe³⁺-mediated multi-pollutant removal in a composite bioreactor and highlighted the potential of this approach for efficient, sustainable, and adaptable management of produced water in the petroleum industry. Full article

Systematic studies were conducted at one of the uranium deposits in Kazakhstan. Native strains of Acidithiobacillus ferrooxidans bacteria were found in leaching solutions at the deposit. The modeling of iron species in the culturing medium was analyzed using Medusa software v.2.0.5. To intensify the process, the bacterial strains were propagated in laboratory conditions, and strains available in the laboratory were added. The ability of bacteria to oxidize divalent iron to trivalent iron at 8 °C in laboratory conditions was established, but the oxidation rate was low. It was found that the limiting stage of bioleaching use in deposit conditions is the temperature mode, the content of divalent iron, and oxygen. A biomass volume of 15 L was initially cultivated under laboratory conditions, and subsequently scaled up to 3 m³ in production using three 1 m³ pachucas with air aeration. In addition, pilot tests were carried out directly in production conditions and biomass in the volume of over 30 m³ was produced. The kinetics of the oxidation process of divalent iron to trivalent iron in 1 g/h under production conditions was established. The features of the bioleaching process at the field are shown as follows: since production, the solution contains the main microelements for the nutrition and reproduction of bacteria, and recommendations for the use of bioleaching are proposed. Research has established that under conditions of a shortage of divalent iron in the solution, sulfuric acid is formed due to sulfur-containing substances. It was observed that for the effective conversion of divalent iron to trivalent iron, bacteria of the provided strain and air (oxygen) supply are sufficient. The corresponding recommendations were issued during the work. Full article

This study introduces an advanced strategy for improving microbial fuel cell (MFC) performance in hexavalent chromium (Cr(VI)) wastewater treatment. A high-performance nano-iron sulfide (nano-FeS) hybridized biocathode was developed by regulating glucose concentration and applying an external voltage. The combination of a glucose concentration of 1000 mg/L and a 0.2 V applied voltage greatly promoted the in situ biosynthesis of nano-FeS, resulting in smaller particle sizes and increased quantities within the biocathode, leading to enhanced electrochemical performance. The MFC with the hybridized biocathode exhibited the highest power density (43.45 ± 1.69 mW/m²) and Cr(VI) removal rate (3.99 ± 0.09 mg/L·h), outperforming the control by 29% and 71%, respectively. The improvements were attributed to the following processes. (1) Nano-FeS provided additional active sites that enhanced electron transfer and electrocatalytic activity, reducing cathode passivation; (2) it protected microorganisms by reducing Cr(VI) toxicity, promoting redox-active substance enrichment and antioxidant enzyme secretion, which maintained microbial activity; (3) the biocathode selectively enriched electroactive and Cr(VI)-reducing bacteria (such as Brucella), fostering a stable and symbiotic microbial community. This study highlights the promising potential of regulating carbon source and external voltage to boost nano-FeS biosynthesis, offering a sustainable and efficient strategy for MFC-based Cr(VI) wastewater treatment with practical implications. Full article

Beneficial interactions between nitrogen-fixing soil bacteria and legumes offer a solution to increase crop yield on Earth and potentially in future Martian colonies. Paraburkholderia phymatum is a nitrogen-fixing beta-rhizobium, which enters symbiosis with more than 50 legumes and can survive in acidic or aluminium-rich soils. In a previous RNA-sequencing study, we showed that the beta-rhizobium P. phymatum grows well in simulated microgravity and identified phymabactin as the only siderophore produced by this strain. Here, the growth of the beta-rhizobium P. phymatum was assessed in Martian simulant soil using Enhanced Mojave Mars Simulant 2 (MMS-2), which contains a high amount of iron (18.4 percent by weight) and aluminium (13.1 percent by weight). While P. phymatum wild-type’s growth was not affected by exposure to MMS-2, a mutant strain impaired in siderophore biosynthesis (ΔphmJK) grew less than P. phymatum wild-type on gradient plates in the presence of a high concentration of MMS-2 or aluminium. This result suggests that the P. phymatum siderophore phymabactin alleviates aluminium-induced heavy metal stress. Ultra-high performance liquid chromatography–mass spectrometry (UHPLC-MS) showed that phymabactin can bind to aluminium more efficiently than iron. These results not only deepen our understanding of the behaviour of rhizobia in simulated extraterrestrial environments but also provide new insights into the potential use of P. phymatum for bioremediation of aluminium-rich soils and the multiple roles of the siderophore phymabactin. Full article

With the growing problem of global water pollution, nitrogen pollution has become a key factor affecting aquatic ecosystems and human health. The biological sponge iron system (BSIS) has gained attention as a research hotspot due to its efficient denitrification capability. This study focused on the changes in microbial community structure and the relative abundance and interrelationships of nitrogen cycle-related functional bacteria at different operational stages of the BSIS with a sponge iron (SFe) dosage of 90 g/L. The results showed that as the operation time of the reactor extended, the relative abundance of denitrifying genera such as Saccharimonadales, Arenimonas, and Acinetobacter significantly increased, while the relative abundance of Proteobacteria showed a trend of initial increase followed by a decrease. The relative abundance of nitrifying bacteria exhibited a more complex variation, whereas the abundance of denitrifying bacteria showed a continuous upward trend. In addition, there were complex interrelationships among different denitrifying bacteria, such as a positive correlation between Saccharimonadales and Acetobacteraceae, and a negative correlation between Rhodothermus and Pseudoxanthomonas. This study not only revealed the changes in the relative abundance and interrelationships of microbial communities and nitrogen cycle-related functional bacteria over time with an SFe dosage of 90 g/L, but also provided a new perspective for understanding the intrinsic mechanism of enhanced biological denitrification by sponge iron. These findings are of great significance for optimizing the operating parameters of the BSIS, improving denitrification efficiency, and promoting the practical application of this technology in the field of environmental engineering. Full article

The aim of this study was to examine the genetic characteristics that could be associated with the virulence characteristics of Escherichia coli collected from clinical samples. A collection of 100 non-repetitive E. coli isolates was analyzed. All isolates were typed by MLST. String production, biofilm formation and serum resistance were examined for all isolates. Twenty E. coli isolates were completely sequenced Illumina platform. The results showed that the majority of E. coli isolates (87%) produced significant levels of biofilm, while none of the isolates were positive for string test and resistance to serum. Additionally, the presence of CRISPR/Cas systems (type I-E or I-F) was found in 18% of the isolates. Analysis of WGS data found that all sequenced isolates harbored a variety of virulence genes that could be implicated in adherence, invasion, iron uptake. Also, WGS data confirmed the presence of a wide variety of resistance genes, including ESBL- and carbapenemase-encoding genes. In conclusion, an important percentage (87%) of the E. coli isolates had a significant ability to form biofilm. Biofilms, due to their heterogeneous nature and ability to make microorganisms tolerant to multiple antimicrobials, complicate treatment strategies. Thus, in combination with the presence of multidrug resistance, expression of virulence factors could challenge antimicrobial therapy of infections caused by such bacteria. Full article

Microbiologically influenced corrosion (MIC) poses significant challenges in oilfield water injection environments, leading to substantial socioeconomic losses. L245 steel, a low-alloy steel widely used in oil and gas pipelines due to its excellent mechanical properties and cost-effectiveness, remains highly vulnerable to MIC during long-term service. This study uses surface characterization and electrochemical techniques to investigate the corrosion behavior of L245 pipeline steel under short-cycle conditions in a symbiotic environment of iron-oxidizing bacteria (IOB) and Shewanella algae (S. algae). Key findings revealed that localized corrosion of L245 steel was markedly exacerbated under coexisting IOB and S. algae conditions compared to monoculture systems. However, the uniform corrosion rate under symbiosis fell between the rates observed in the individual IOB and S. algae systems. Mechanistically, the enhanced corrosion under symbiotic conditions was attributed to the synergistic electron transfer interaction: IOB exploited electron carriers secreted by S. algae during extracellular electron transfer (EET), which amplified the microbial consortium’s capacity to harvest electrons from the steel substrate. These results emphasize the critical role of interspecies electron exchange in accelerating localized degradation of carbon steel under complex microbial consortia, with implications for developing targeted mitigation strategies in industrial pipelines exposed to similar microbiological environments. Full article

Rice paddy fields are sustainable agricultural systems as soil microorganisms help maintain nitrogen fertility through generating ammonium. In these soils, dissimilatory nitrate reduction to ammonium (DNRA), nitrogen fixation, and denitrification are closely linked. DNRA and denitrification share the same initial steps and nitrogen gas, the end product of denitrification, can serve as a substrate for nitrogen fixation. However, the microorganisms responsible for these three reductive nitrogen transformations, particularly those focused on ammonium generation, have not been comprehensively characterized. In this study, we used stable isotope probing with ¹⁵NO₃⁻, ¹⁵N₂O, and ¹⁵N₂, combined with 16S rRNA high-throughput sequencing and metatranscriptomics, to identify ammonium-generating microbial consortia in paddy soils. Our results revealed that several bacterial families actively contribute to ammonium generation under different nitrogen substrate conditions. Specifically, Geobacteraceae (N₂O and +N₂), Bacillaceae (+NO₃⁻ and +N₂), Rhodocyclaceae (+N₂O and +N₂), Anaeromyxobacteraceae (+NO₃⁻ and +N₂O), and Clostridiaceae (+NO₃⁻ and +N₂) were involved. Many of these bacteria participate in key ecological processes typical of paddy environments, including iron or sulfate reduction and rice straw decomposition. This study revealed the ammonium-generating microbial consortia in paddy soil that contain several key bacterial drivers of multiple reductive nitrogen transformations and suggested their diverse functions in paddy soil metabolism. Full article

The increasing prevalence of antimicrobial resistance alongside the pharmacological limitations and adverse effects associated with conventional antibiotics necessitates the development of novel and efficacious antimicrobial agents. In this study, magnetic iron oxide nanoparticles (MIONPs) were synthesized via a chemical co-precipitation method. Activated carbon (AC) derived from Hibiscus esculentus (HE) fruit was coated onto the nanoparticle surfaces to fabricate MIONPs/HEAC nanocomposites. To augment their antimicrobial properties, silver ions were chemically reduced and deposited onto the MIONPs/HEAC surface, yielding MIONPs/HEAC@Ag nanocomposites. Comprehensive characterization of the synthesized nanocomposites was performed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM), dynamic light scattering (DLS), and zeta potential analysis. DLS measurements indicated average particle sizes of approximately 122 nm and 164 nm for MIONPs/HEAC and MIONPs/HEAC@Ag, respectively. Saturation magnetization values were determined to be 73.6 emu/g for MIONPs and 65.5 emu/g for MIONPs/HEAC. Antibacterial assays demonstrated that MIONPs/HEAC@Ag exhibited significant inhibitory effects against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923, with inhibition zone diameters of 11.50 mm and 13.00 mm, respectively. In contrast, uncoated MIONPs/HEAC showed negligible antibacterial activity against both bacterial strains. These findings indicate that MIONPs/HEAC@Ag nanocomposites possess considerable potential as antimicrobial agents for biomedical applications, particularly in addressing infections caused by antibiotic-resistant bacteria. Full article