Search Results (9,260)

Alkanes are saturated hydrocarbons that serve as available and cost-effective feedstock for producing alkenes, key intermediates in numerous industrial processes. A mutant bacterial strain, Rhodococcus sp. KSM-B-3M, was previously reported to efficiently convert alkanes into alkenes and was later utilized by us to selectively transform linear alkanes into a variety of alkyl derivatives through a two-step process. Here, we explored the biological mechanisms underlying the unique biotransformation capability of strain KSM-B-3M by integrating genomics, transcriptomics, proteomics, and 3D-structural modelling. Strain KSM-B-3M demonstrated downregulation of the fatty acid degradation pathway, lacking the pR8L1 megaplasmid that carries multiple fatty acid degradation genes, accompanied by a parallel high expression of the acyl CoA-desaturase gene. Partial curing of the pR8L1 plasmid from a wild-type (WT) strain conferred the ability to dehydrogenate n-hexadecane to cis-hexadecene. Overexpression of the acyl-CoA desaturase gene similarly induced cis-hexadecene formation in the WT strain, acting cumulatively with fatty acid degradation downregulation. Acyl CoA-desaturase 3-D modeling suggested that the enzyme directly dehydrogenates n-hexadecane to form cis-hexadecene, supporting its direct role in this unique biotransformation. These findings advance our understanding of the mechanism behind this biotransformation, which holds promise for sustainable and cost-effective production of alkyl derivatives. Full article

Camel milk is widely consumed in the world’s arid and semi-arid regions because of its favorable nutritional profile and associated human health benefits. The indigenous microbiota of raw camel milk is diverse and composed of different bacterial and fungal groups. This community drives spontaneous milk fermentation, resulting in a variety of traditional products, including Gariss, Shubat, Chal, Dhanaan, Lfrik, and Suusac (or Suusa), depending on geographic region and cultural practice. This fermented milk has improved sensory, nutritional, and health profiles, as well as an extended shelf life, compared to raw milk. Fermentation alters the microbial community structure, with lactic acid bacteria (LAB) consistently becoming dominant, while yeasts and molds are also detected in some products. These patterns have been identified using both culture-dependent and culture-independent approaches, including 16S rRNA gene sequencing and whole-genome shotgun metagenomics. However, the milk’s microbial composition is highly variable and is influenced by the original composition, geographical location, fermentation and hygiene practices. The detection of opportunistic pathogens such as E. coli, Salmonella and Listeria in some traditional products raises important food safety concerns. This review presents current knowledge on fermented camel milk microbiology using a cross-regional approach, identifying key gaps in microbial safety and process standardization to support wider acceptance and potential commercialization. Full article

Metal-contaminated dredged sediments represent heterogeneous environmental matrices in which remediation responses are frequently constrained by elevated background metal loads and complex geochemical conditions. Within such systems, phytoremediation has been discussed as a nature-based management approach whose outcomes depend on plant biomass, internal metal allocation, and context-dependent interactions between plants and sediment. The present study evaluated whether bacterial and fungal plant growth-promoting microorganisms (PGPMs) were associated with changes in plant metal uptake and internal allocation in Sorghum bicolor L. and Cannabis sativa L. grown in dredged sediment collected from the Bega Canal. An outdoor pot experiment was conducted under environmentally relevant conditions, including bacterial and fungal inoculation treatments alongside non-inoculated controls, with plant responses to Cr, Ni, Cu, Zn, As, Cd, and Pb characterized using concentration- and mass-based uptake metrics, root–shoot partitioning, and sediment geochemical assessment based on pseudo-total concentrations and BCR sequential extraction fractions. Across treatments, plant responses were largely governed by intrinsic species traits and biomass production, while PGPM-associated effects remained modest and variable. Root-dominated metal retention and limited translocation were evident irrespective of species, consistent with a phytostabilization-type response rather than systematic extraction. Absolute metal uptake accounted for only a minor fraction of total sediment metal pools, underscoring the importance of interpreting concentration-based indices jointly with mass-based metrics when evaluating system-scale responses. Altogether, the findings indicate that under the investigated outdoor dredged sediment pot conditions, PGPM inoculation acts primarily as a context-specific modulator of plant responses rather than a driver of enhanced phytoremediation performance, reflecting the central role of intrinsic plant traits and stabilization-oriented processes in complex sediment systems. Full article

The impact of microplastic pollution on soil functions and the ecological toxicity to crops is a hotspot in agronomy and environmental science. In this study, a pot experiment was conducted to examine the effects of polyethylene microplastics (PE-MPs) at concentrations of 0.25%, 0.5%, 2.5%, and 5% on the growth, physiological indicators, soil physical and chemical properties, and soil bacterial community diversity of Amaranthus tricolor L. The results showed that adding PE-MPs inhibited the growth of A. tricolor L. stems and leaves, and as the dosage increased, the aboveground fresh weight decreased by 13.5% to 60.7%. At the same time, the chlorophyll content in A. tricolor L. leaves decreased, whereas the malondialdehyde (MDA) content increased by up to 11.8%. When the added dosage of PE-MPs was ≥0.5%, soil porosity and available phosphorus (AP) content significantly decreased, resulting in a significant reduction of 22.1% to 31.3% in the phosphorus content of the aboveground parts of A. tricolor L. compared with controls (CK). High-throughput sequencing results indicated that adding PE-MPs could reduce the Shannon index of the soil bacterial community and increase the Simpson index, suggesting a decrease in diversity. The addition of PE-MPs also altered the structure of the soil bacterial community, increasing the relative abundance of the Acidobacteriota, while the abundance of the Planctomycetota significantly decreased. This study provides a numerical and theoretical basis for evaluating the impact of microplastics on vegetable production and soil ecological environment effects. Full article

Fresh cowpeas have a limited shelf life at room temperature. Fermentation of cowpeas not only preserves their nutritional value but also prolongs their shelf life. This study categorized cowpea fermentation processes into natural and inoculated methods, focusing on analyzing physicochemical indices, acid production, and bacterial diversity throughout the cowpea fermentation process. We compared the moisture, protein content, and vitamin C levels of cowpeas. The acidification process was monitored using pH, total acid, and nitrite contents as indicators. Illumina MiSeq sequencing was employed to analyze the bacterial communities in fermented cowpeas at different fermentation stages. The experimental results indicated that during fermentation, pH, total acid content, and nitrite content all changed significantly. Lactobacillus exhibited high dominance in both natural fermentation and inoculated fermentation processes. Moreover, under inoculated fermentation conditions, its population size was significantly greater than that in natural fermentation. Analysis of bacterial community composition revealed that microbial diversity tended to decrease with prolonged fermentation time in both natural and inoculated fermentation systems. The results demonstrate that inoculation fermentation can shorten the fermentation cycle, lower nitrite levels, and confirm that lactic acid bacteria are the dominant microbial genus in vegetable fermentation. Full article

Effective reprocessing of surgical instruments is essential to prevent healthcare-associated infections in the field of veterinary medicine. However, chemical disinfectants are frequently used as alternatives to sterilization in small animal clinics, particularly in resource-limited settings. This preliminary exploratory study evaluated routine chemical disinfection practices and residual bacterial contamination of surgical instruments in veterinary clinics in Veracruz, Mexico. A cross-sectional study was conducted in ten small animal veterinary clinics. Samples were collected from the surgical instruments and operative surfaces immediately after routine chemical disinfection. Bacterial isolation was performed using conventional culture methods, and microbial identification was performed using MALDI-TOF mass spectrometry. Descriptive analysis and Fisher’s exact test were used to explore the association between disinfectant category and bacterial contamination. Bacterial growth was detected in 19 of the 60 samples (31.6%). The identified microorganisms included Bacillus, Staphylococcus, Pseudomonas, Acinetobacter, and Burkholderia species. Most clinics relied on low-level disinfectants, particularly benzalkonium chloride (BAC). Residual contamination was more commonly observed in clinics reporting the use of low-level disinfectants, particularly benzalkonium chloride-based products. However, these findings should be interpreted cautiously because of the exploratory observational design and limited sample size. These results suggest that routine chemical disinfection, particularly when low-level disinfectants are used, may not always achieve complete microbial elimination under real-world clinical conditions. Improved infection prevention and instrument reprocessing practices are required in veterinary clinical settings. From a One Health perspective, strengthening infection control measures in veterinary clinics may help reduce microbial circulation among animals, veterinary personnel, and the environment. Full article

Salinization of agricultural soils is a global problem causing crop yield declines. This impact is caused by osmotic and oxidative stress, which plants often rely on endophytic bacteria to overcome. A bacterial isolate from the roots of the halophyte Plantago salsa was studied between 2024 and 2026, and its ability to increase barley tolerance to moderate salt stress was determined. Based on 16S rRNA gene sequencing (1410 bp), the isolate PS-50.1 was identified as Providencia sp. It demonstrated key plant growth-promoting properties, including indole-3-acetic acid production (21.4 mg L⁻¹) and phosphate solubilization (69.0 mg L⁻¹). The strain supported barley growth at 7% NaCl. Inoculation of barley seeds with this strain (10⁸ CFU L⁻¹) significantly reduced moderate salt stress in plants both in vitro and in a pot experiment. Inoculated plants under salinity conditions had greater shoot length (+11.6%) compared to non-inoculated; higher pre-flag leaf fresh weight; demonstrated decreased levels of prooxidants (H₂O₂ by 44.8% and malondialdehyde by 31.8%), higher proline accumulation (up to 2.0-fold), and increased antioxidant enzyme activity (catalase by 26.6% and ascorbate peroxidase by 191%). Furthermore, inoculated plants showed 9.4% higher water use efficiency and photosynthetic rate (+5.5%) under salt stress compared to uninoculated plants. These results indicate that the halophytic strain Providencia sp. PS-50.1 is a promising candidate for the development of microbial preparations aimed at increasing crop productivity under saline conditions. Full article

Background/Objectives: Parabens are widely used preservatives detected at trace levels in drinking water. Although their endocrine-disrupting effects are well established, their long-term impact on environmental bacteria remains poorly understood. This study investigated the effects of parabens on changes in bacterial phenotypic virulence traits and antimicrobial tolerance of bacteria within drinking water biofilms. Methods: Acinetobacter calcoaceticus and Stenotrophomonas maltophilia biofilms were grown on polyvinyl chloride coupons for 26 days under exposure to methyl- (MP), propyl- (PP), butyl-paraben (BP), or a paraben mixture (MIX) at 0.15 µg/L. Biofilm regrowth and virulence-associated traits, including motility (swimming, swarming, and twitching), extracellular enzymes (gelatinase, protease, and lipase), and siderophore production, were evaluated. The effect of prolonged MP exposure (10 weeks) on antimicrobial tolerance was assessed. Results: In A. calcoaceticus, MP reduced biofilm biomass by 32%, whereas MIX increased biomass by 25% and culturability (1.1-fold). S. maltophilia showed increased biofilm culturability with PP (50%), and increased biomass of 2.6-, 2.4-, and 1.8-fold for PP, BP, and MIX, respectively. Biofilm cells exhibited higher virulence factor production than planktonic counterparts. S. maltophilia biofilm cells exposed to BP and MIX showed enhanced swimming and swarming motility, with halo diameters up to fivefold larger than controls. Lipase production increased under BP and MIX exposure, whereas MP exposure reduced it. A MP-induced reduction in motility was observed for A. calcoaceticus and S. maltophilia. Long-term MP exposure results in reduced susceptibility to ceftazidime and minocycline in A. calcoaceticus. Conclusions: Environmentally relevant concentrations of parabens can modulate bacterial virulence traits, increasing biofilm formation, motility and lipase production, and antimicrobial tolerance. Full article

Potato (Solanum tuberosum L.) is an important staple and food security crop to many communities in the world. However, potato production and quality is greatly constrained by bacterial wilt, a disease caused by a soil-borne pathogen, Ralstonia solanacearum. Ralstonia solanacearum can be managed through clean seed systems and therefore laboratory testing is a pre-requisite for seed certification to confirm the absence of the pathogen in potato seeds before planting. Molecular diagnostics is the gold standard for detection of R. solanacearum in potato seeds. However, the extraction of genomic DNA from R. solanacearum for molecular diagnostics is complex, tedious, lengthy and/or costly procedure. A simple, rapid and reliable DNA extraction protocol is required for use in routine molecular diagnosis of R. solanacearum, a high-risk quarantine pathogen. In this study, we developed a simple and rapid protocol for extracting genomic DNA from symptomatic and asymptomatic potato tubers infected with R. solanacearum and verified its efficiency for the detection and molecular characterization of the pathogen. The protocol was developed from the evaluation of distilled water, Tris-EDTA (TE) and Tris buffer as a base solution for tissue maceration. The DNA quantity and integrity was determined using the NanoDrop 2000C spectrophotometer and agarose gel electrophoresis, respectively. Both hot and cold solutions produced intact high molecular weight genomic DNA of sufficient yield and purity for molecular-based applications. The detection and determination of phylotypes of R. solanacearum, based on conventional and multiplex polymerase chain reaction (PCR), amplified the expected 280 and 372 bp amplicons, respectively, confirming that the quantity and quality of the extracted pathogen genomic DNA was sufficient for molecular diagnostic applications. The sequencing of the amplified products of the endoglucanase gene produced good quality sequences, which confirmed the R. solanacearum isolates to be members of phylotype II sequevar 1. This protocol is a simple, fast and reliable tool for the extraction of sufficient genomic DNA with high quality, directly from R. solancearum-infected potato tubers for PCR and sequencing applications. Its simplicity and throughput make it valuable for use in routine diagnostics and can be adopted by certification programs to ensure distribution of clean potato seeds to farmers. Full article

Soil salinization is a challenge for global agriculture and can affect the yield of staple crops such as maize. Plant growth-promoting rhizobacteria (PGPR) are known to play a pivotal role in enhancing plant growth and stress resilience. However, no studies so far have reported plant growth-promoting (PGP) activity in members of the genus Marinobacter. In this study, a novel strain of Marinobacter sp. ZP-590, was identified as a PGPR based on a polyphasic taxonomic analysis, which was isolated from the rhizosphere soil of Tamarix chinensis Lour. Genomic analysis revealed that ZP-590 possesses 5370 protein-coding genes, including core metabolic, catalytic, and transport functions essential for bacterial survival and plant interactions, along with multiple genes potentially associated with PGP traits such as phosphate solubilization, nitrogen fixation, and the production of siderophore and exopolysaccharide (EPS), tryptophan (a prerequisite for IAA synthesis), and amylase. These genomic predictions were functionally validated through in vitro assays confirming all predicted PGP activities. Pot experiment results suggested that inoculation with ZP-590 enhanced maize growth under saline conditions. Compared to the non-inoculated controls, the treatment significantly increased root fresh weight (14.25%; p < 0.05) and stem fresh weight (125.04%; p < 0.01), while shoot height and leaf fresh weight showed no significant changes. Metabolomic profiling revealed that ZP-590 inoculation was associated with systemic metabolic changes in maize under saline conditions. A total of 394, 262, and 601 differentially accumulated metabolites in the root, stem, and leaf, respectively. These changes were characterized by a substantial up-regulation of antioxidant compounds, notably flavonoids, and changes in carbohydrate and lipid metabolism pathways. The changes in carbohydrate and lipid metabolism pathways may contribute to the supply of energy and structural components for stress adaptation. Meanwhile, the accumulation of antioxidant compounds significantly mitigated saline-induced oxidative damage by reducing the levels of superoxide anion (O₂⁻) in leaves. In this study, Marinobacter sp. ZP-590 is characterized as a PGPR that promotes maize growth under saline conditions. These findings provide a foundation for investigating the molecular mechanisms underlying the interaction between ZP-590 and maize under saline conditions. Full article

Opportunistic bacterial and fungal infections from surface wounds remain a persistent threat to aquaculture, resulting in significant economic losses and reduced stock welfare. Topical wound sealants are widely employed in recreational aquaculture applications, yet no market regulation or efficacy data exist to support their usage. The broader biological/environmental impacts of these products also remain poorly characterized. This study provides the first quantitative assessment of the antibacterial, antifungal and cellular toxicity of a panel of commercially available topical ‘carp care’ formulations. Our data highlights highly variable to no functional growth inhibition or killing of microbial pathogens, significant inherent cyprinid cellular toxicity, and lack of submerged wet adhesion in all products tested. We show for the first time that commercial propolis solutions are ineffective against the four main pathogenic microorganisms affecting carp. Propolis formulations were also found to induce apoptosis and ROS generation in cyprinid cells in vitro, and permeabilise intact carp skin, questioning the foundation of propolis formulations in topical wound-care treatments for carp rearing/angling. We show improved efficacies can be attained through natural compound implementation, with increased antibacterial and antifungal effects, inherent regenerative benefits to cyprinid fibroblasts, and improved human and environmental safety profiles. This research demonstrates the widespread lack of efficacy in currently commercially available wound sealants for carp; of those tested here, many popular formulations are in fact inherently toxic to carp cells, and also have a permeabilizing effect on intact carp skin due to carrier solvent effects, providing a route for secondary infection; most show no activity against any common carp pathogens; and all uniformly lacked wet adhesion. This work provides a framework standard for the future development of topical wound-care formulations for carp and highlights the need for better dialogue between trade and academia when designing novel wound-care products. Full article

Sulfane sulfur species are increasingly recognized as integral cellular components involved in signaling pathways and cytoprotection against oxidative stress in mammals. While their production in bacteria has been extensively studied, their functional role in bacterial oxidative stress defense remains poorly understood. Here, we demonstrate that sulfane sulfur generated by sulfide: quinone oxidoreductase decreases H₂O₂ sensitivity in Pseudomonas aeruginosa PAO1. Notably, this protective mechanism does not depend on sulfane sulfur acting as a direct H₂O₂ scavenger via nucleophilic reactions. Through persulfidation proteomic profiling, we reveal that persulfidation is a prominent post-translational modification in P. aeruginosa, reflecting the prevalence of deprotonated sulfane sulfur species. These species modify cysteine residues in proteins, including the well-known oxidative stress regulator OxyR. Specifically, sulfane sulfur modifies OxyR at Cys199 to form persulfidated OxyR C199-SSH, contributing to a single-Cys activated state that modulates promoter activity and DNA-binding affinity. Furthermore, sulfane sulfur-mediated persulfidation protects the critical cysteine residue of LpdG, a ROS-vulnerable dihydrolipoamide dehydrogenase, from irreversible overoxidation. Although LpdG is not part of the canonical H₂O₂-scavenging system, its preservation is essential for cell viability under oxidative stress. These findings establish endogenous sulfane sulfur species as key mediators of antioxidant defense in P. aeruginosa. Full article

Plant growth-promoting fungi (PGPF) have shown broad potential to improve soil conditions and enhance root growth and development. However, few studies have examined the effects of exogenous PGPF inoculation on the growth of the medicinal plant Saposhnikovia divaricata and the associated changes in the rhizosphere microbiome. In this study, Aspergillus neoalliaceus MR-86 exhibited phosphate solubilization, growth in nitrogen-free medium, potassium solubilization, IAA production, and siderophore production. PCR assays did not detect the aflatoxin biosynthesis-related genes aflR, aflS, and omtA in strain MR-86. Pot trials demonstrated that inoculation with MR-86 significantly increased the plant height and root dry weight of S. divaricata by 10.32% and 21.05%, respectively (p < 0.05). In the rhizosphere, soil pH decreased, whereas soil alkaline-hydrolyzable nitrogen and available phosphorus levels, as well as the activities of protease, urease, and cellulase, increased significantly. Illumina NovaSeq sequencing revealed that MR-86 inoculation altered the soil microbial community structure and specifically enriched several microbial taxa, including Talaromyces, Subulicystidium, and Aspergillus. Moreover, MR-86 inoculation did not alter the composition of dominant bacterial and fungal phyla, but significantly modified microbial interactions and the topology of microbial networks. Correlation analysis indicated that the specific microbial taxa Subulicystidium, Aspergillus, and Talaromyces were positively associated with soil nutrient indices, enzyme activities, and plant growth parameters. Functional prediction analysis indicated that MR-86 treatment was predicted to be enriched bacterial metabolic pathways, including flavone and flavonol biosynthesis and ether lipid metabolism, and was predicted to increase the relative abundance of functional fungal groups such as ectomycorrhizal and wood-decomposing fungi. In summary, A. neoalliaceus MR-86 may contribute to improved growth of S. divaricata by enhancing nutrient availability and transformation and by modulating the structure and function of the rhizosphere microbiome. Full article

Background: Caffeine, although widely used in dermatological and cosmetic products, exhibits limited permeability through the stratum corneum, highlighting the need for strategies for optimizing delivery. The aim of this study was in vitro investigation of the effects of probiotic bacterial lysates and submicellar concentrations of bile acids on caffeine permeation, with a particular focus on permeation kinetics. Methods: Caffeine permeability was evaluated using the Skin Parallel Artificial Membrane Permeability Assay (Skin-PAMPA). Donor and acceptor concentrations were quantified by HPLC at predefined time points (1, 2, 4, 6, and 12 h), followed by calculation of apparent permeability coefficients, cumulative permeation profiles, and interval permeation rates in systems containing probiotic lysates and submicellar concentrations of cholic acid (CA) or deoxycholic acid (DCA). Results: Probiotic lysates significantly reduced caffeine permeability (0.98 ± 0.02 × 10⁻⁶ vs. 1.57 ± 0.14 × 10⁻⁶ cm/s in the control group) and modified transport kinetics resulting in lower early-phase interval permeation rates and reduced cumulative permeation. Conversely, bile acids increased the apparent permeability of caffeine, with the highest value observed in the DCA group (2.30 ± 0.08 × 10⁻⁶ cm/s). Conclusions: Overall, probiotic lysates and bile acids modulated caffeine permeation across the Skin-PAMPA membrane primarily by reshaping permeation kinetics rather than simply changing overall permeability. Their combined effects may provide a basis for designing topical formulations with tailored permeation profiles. Full article

Mycobacterium tuberculosis (Mtb) continues to pose a significant global health risk, primarily due to its capacity to modulate host immune responses and achieve prolonged persistence. Recent evidence has increasingly underscored the significance of epigenetic reprogramming as a principal mechanism through which Mtb modifies host cellular functions without altering the fundamental DNA sequence. This review gives a full picture of how Mtb secretory proteins work as nucleomodulins to directly target host chromatin and control gene expression. Mtb uses special secretion systems, such as the ESX (Type VII) and SecA2 pathways, to enable effector proteins to enter host cells. Some of these proteins move to the nucleus and interact with machinery that is linked to chromatin. These nucleomodulins facilitate various epigenetic modifications, encompassing non-canonical histone methylation, DNA methylation, and the modulation of histone acetylation, resulting in extensive transcriptional reprogramming of immune-related genes. These changes make important host defence mechanisms less effective, such as macrophage activation, antigen presentation, cytokine production, and antimicrobial responses. This helps bacteria survive and avoid the immune system. Epigenetic remodeling also affects the polarization and metabolic states of macrophages, which further affect the progression of disease. The reversible characteristics of epigenetic modifications offer a significant prospect for host-targeted therapeutic strategies. Targeting enzymes such as histone deacetylases and DNA methyltransferases has shown potential in restoring immune function and enhancing bacterial clearance, particularly when used in combination with conventional anti-tubercular therapies. Even with these improvements, there are still big problems with fully understanding the functional diversity of Mtb secretory proteins and turning these discoveries into useful medical tools. In general, understanding how Mtb-secreted nucleomodulins and host epigenetic regulation interact is important for understanding how tuberculosis works and finding new ways to treat it. Full article