Bacteria sense, respond, and adapt to rapidly changing environments through highly sensitive intracellular networks. Among them, cyclic-di-GMP (c-di-GMP) is a well-characterized second messenger controlling the transition from planktonic to sessile lifestyles, making it a key determinant of bacterial adaptation and survival. Two main approaches have been developed to investigate c-di-GMP dynamics. The first uses biological biosensors for live-cell monitoring of intracellular c-di-GMP through transcriptional reporters, RNA-based sensors, or protein-based sensors. Their main advantage is real-time, spatiotemporal analysis in living cells, although they generally do not provide absolute quantification. The second approach relies on analytical chemistry, particularly liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), which enables sensitive and accurate quantification of intracellular c-di-GMP across diverse bacterial species. However, the lack of standardized extraction protocols and the need for cell lysis prevent real-time measurements, providing only a snapshot of the total c-di-GMP pool. These approaches are complementary: biosensors reveal dynamic, single-cell responses, whereas LC-MS/MS provides precise global quantification. Nevertheless, most studies rely on only one method, limiting a comprehensive understanding of c-di-GMP biology. Combining both approaches would provide a more integrated view of c-di-GMP signaling and its role in bacterial physiology.
Real-time polymerase chain reaction (PCR) has reshaped bacterial infectious disease diagnostics, yet important interpretive gaps remain regarding the relationship among molecular detection, cycle threshold (Ct) values, microbial viability, culture findings, and phenotypic antimicrobial susceptibility. In particular, Ct values are frequently overinterpreted as direct surrogates for viable bacterial burden, and PCR–culture discordance may be interpreted without sufficient consideration of the distinct biological information provided by each method. This review therefore aims to clarify the complementary biological and analytical roles of PCR and bacterial culture, critically examine the determinants and limitations of Ct interpretation and PCR–culture discordance, and provide a practical framework for integrating molecular detection, culture, and antimicrobial susceptibility testing (AST) into clinically and stewardship-informed decision-making. The genotypic lens of PCR (detection of target nucleic acid and resistance genes) is contrasted with the phenotypic lens of bacterial culture and AST, emphasizing that genotype and phenotype distinguish biological layers and account for common PCR–culture discordance. Evidence on Ct variability, assay design, inhibition, and panel scope is synthesized to demonstrate why Ct is inherently assay-specific and non-portable across platforms. Accordingly, MIQE-aligned quality safeguards and assay-specific principles are presented to guide the interpretation of Ct values. Bedside decision tables then integrate Ct patterns, specimen sterility, and patient acuity to support treatment, observation, or additional testing. As a narrative review of heterogeneous evidence, this synthesis does not provide pooled estimates or a uniform risk-of-bias assessment. The proposed Ct categories and clinical framework should therefore be viewed as assay-specific guidance, not universally validated thresholds. Finally, a stepwise workflow is outlined in which PCR is used for rapid rule-in, while culture and AST are retained for confirmation, de-escalation, and dosing. This integrated approach reframes Ct as a qualified signal rather than a standalone truth, supporting faster yet biologically grounded and stewardship-consistent infectious disease management.
Lactobacilli are Gram-positive fermentative bacteria with GRAS (“Generally Recognized As Safe”) status. Since 2017, it has been reported that many lactobacilli strains can form extracellular vesicles. Extracellular vesicles (EVs) are spherical bilayered membrane structures of nanometric size that carry cytoplasmic components. Bacterial EVs are considered important mediators between host and commensal bacteria, but their biological effects have not been widely studied. The purification of EVs involves methodological difficulties. Due to their nanometric size, EVs are prone to being co-purified with media compounds, which interfere with their characterization. The present work aimed to obtain high-purity EVs and to determine their physicochemical properties. To achieve the objectives, we developed a minimal synthetic medium (MSM) suitable for the growth of Lactiplantibacillus plantarum CIDCA 83114 and also designed a protocol to concentrate and obtain its EVs. The medium was free of high-molecular-weight compounds and surfactants, and the purification protocol included EV concentration via a tangential flow filtration step. The EVs obtained had an average size of 110 nm ± 40 nm and a negative zeta potential. They exhibited a mean protein content of 100 µg/mL with a clear protein profile absent in the culture media. EVs also contain RNA and scarce DNA. Our work contributed to improving the purification of lactobacilli EVs by replacing the traditional medium used in lactic acid bacteria growth (MRS) with a synthetic minimal medium (MSM). The design of the MSM allows for high-purity vesicles to be obtained and accurately characterized.
This study aimed to investigate the microbiome profile of Culex pipiens, the most abundant mosquito and pathogen vector in the Palearctic, and to find microbiome region and ecotype specificity. The taxon Cx. pipiens includes two ecotypes—pipiens and molestus—and their hybrids, which differ in their epidemiological role. Microbiomes were extracted using bioinformatic analysis from whole-genome datasets of 47 individual Cx. pipiens (pipiens and molestus forms and their hybrids) collected from seven geographically and climatically distinct Russian regions. The dominant phyla and genera were identified, along with a fourfold decrease in microbiome diversity during the transition from larva to adult, and a negative effect of Wolbachia on Cx. pipiens microflora diversity. Microbiome community composition differed significantly between the majority of geographical groups. Analysis of microbial community composition points to anthropogenically altered ecosystems in mosquito habitats. Microbes specific to certain geographical locations were identified. Both forms, pipiens and molestus, share a phylogenetically similar core of dominant taxa but differ in their abundances. A shared core microbiome, present across all samples, is most likely essential for the normal development and survival of Cx. pipiens, and may serve as a target for pathogen-blocking paratransgenesis and region-specific control strategies.
Cocoa fermentation is a critical postharvest process that determines the physicochemical and sensory quality of cocoa beans through complex microbial and biochemical transformations. This study evaluated the effect of selected lactic acid bacteria (LAB), i.e., Weissella confusa and Lactiplantibacillus plantarum, and the fermentation system on the fermentation dynamics and final quality of two cocoa genotypes (i.e., Theobroma cacao L.; Nacional and CCN-51). A completely randomized 2 × 2 × 2 factorial design was applied, considering cocoa genotypes, LAB species, and fermentation system (i.e., laboratory fermentation and cascade-type box fermentation). During fermentation, pH, temperature, and total soluble solids (°Brix) were monitored at 0, 24, 48, and 72 h. In addition, cut test parameters and the physicochemical properties of the final cocoa paste were evaluated. The results showed a progressive decrease in pH (from 3.13 to 4.17), accompanied by a temperature increase up to 46.50 °C and a marked reduction in soluble solids during the final fermentation stages, reflecting intense microbial metabolism and substrate utilization. Treatments inoculated with L. plantarum achieved the highest proportion of well-fermented beans (up to 93.73%), indicating enhanced fermentation performance. Furthermore, the physicochemical properties of the final cocoa paste, including moisture, fat, ash, pH, and °Brix, were significantly influenced by the interaction among cocoa genotype, LAB species, and fermentation system. Overall, controlled fermentation using selected LAB species represents a promising biotechnological strategy for improving cocoa fermentation consistency and enhancing postharvest cocoa quality.
Prebiotic potential refers to the stimulation of beneficial bacteria over pathogenic strains. This preliminary study evaluated the prebiotic potential of five agave-derived carbohydrate preparations using lactic acid bacteria (LAB) and Escherichia coli (pathogenic) strains. The tested substrates included commercial inulin, commercial agave syrup, artisanal maguey syrup, aqueous and cooked agave extract. Six Lactobacillus strains (Lactobacillus acidophilus, Lacticaseibacillus casei, Lactiplantibacillus plantarum ATCC 8014, Limosilactobacillus reuteri NRRL B-14171, Lactiplantibacillus plantarum NRRL B-4496, and Lacticaseibacillus rhamnosus) were evaluated against E. coli ATCC 43888 and E. coli clinical isolates. Carbohydrate characterization included analyses of total and reducing carbohydrates and thin-layer chromatography (TLC) to assess the degree of polymerization (DP). Prebiotic Index (PI) and Prebiotic Activity Score (PAS) were calculated to determine selective growth stimulation at 24 and 48 h. TLC analysis revealed two distinct groups: high-molecular-weight compounds (aqueous agave extract and commercial inulin), and low-molecular-weight compounds (cooked agave extract, commercial agave syrup, and artisanal maguey syrup). L. reuteri NRRL B-14171 exhibited the highest PI (approaching 2.0) with aqueous agave extract at 24 h. L. rhamnosus demonstrated superior PAS values across all prebiotic sources, while commercial inulin and artisanal maguey syrup showed the most favorable PAS values against clinical E. coli isolates, indicating preferential in vitro growth of LAB over the pathogen. These findings represent preliminary indications of selective carbohydrate utilization by LAB strains under controlled in vitro conditions. Further studies, incorporating digestion resistance, fermentation by complex microbiota, metabolite production, and host-related effects are required before confirming prebiotic functionality.
High fructose intake rapidly induces protein glycation, oxidative stress, inflammation, and disturbances in the cultivable fraction of gut bacteria, contributing to early metabolic impairment. This study examined whether selected plant-derived bioactives and a prebiotic–probiotic formulation could mitigate fructose-induced biochemical and microbial alterations. Male Wistar rats were fed fructose for 45 days, and advanced glycation end product (AGE)-associated fluorescence, oxidative stress markers, and lipid peroxidation were measured to assess metabolic changes. Culture-dependent enumeration of intestinal and fecal bacteria was performed to evaluate shifts in cultivable aerobic and facultative bacterial counts, while limonene, eugenol, and emodin were tested for antibacterial activity against aerobic and facultative bacterial isolates obtained from fructose-fed rats during our previous study. The prebiotic–probiotic formulation was assessed alone and in combination with these bioactives. Fructose feeding increased protein glycation, oxidative stress, lipid peroxidation, and reduced counts of cultivable gut bacteria. Treatment with the bioactives and the formulation lowered glycation-related fluorescence, reduced oxidative stress, and decreased lipid peroxidation. The bioactives exhibited antioxidant and antiglycation activity and inhibited growth of selected cultivable bacterial isolates, including Corynebacterium stationis. While emodin contributed primarily through its known α-glucosidase inhibitory and antiglycation properties rather than antibacterial activity. Combined treatment partially restored cultivable bacterial counts and improved metabolic parameters. Overall, the interventions attenuated fructose-induced biochemical disturbances and modulated the cultivable gut bacterial counts, suggesting a complementary approach to managing early metabolic changes in rats associated with high fructose intake.
This research focused on the plant growth-promoting properties of endophytic bacteria isolated from Morisonia scabrida, a tree adapted to heat stress. Sixteen bacterial strains were isolated; among them, S1R21 tolerated 50 °C; S1H21 inhibited the growth of Fusarium sp. FH at 25 and 30 °C; and S1R16 inhibited Alternaria sp. ATCC20084 and F. oxysporum CTLM12 at 25 and 30 °C. Regarding enzymatic activities, S1R21 exhibited amylase activity at 30 °C; S1T20 showed proteinase activity at 37 °C; S1T11 showed pectinase activity at 37 °C; S1R16 and S1R9 demonstrated lipase activity; and S1R20 showed CMCase activity at 30 °C. S1T1 solubilized tricalcium phosphate at 25 and 30 °C; S1H5 produced siderophores at 30 °C; and S1T11 produced IAA and fixed nitrogen at 30 and 37 °C. With respect to germination percentage of corn and alfalfa, the highest values were achieved with strain S1R21 at 30 and 37 °C. Seven strains were selected and identified by 16S rDNA analysis as Bacillus albus S1H21, Bacillus cereus S1R21, Lysinibacillus fusiformis S1R9, Enterobacter sp. (S1H5 and S1R8), Klebsiella sp. S1R16 and Stutzerimonas stutzeri S1T11. Most of these strains increased growth parameters of Zea mays and Medicago sativa, with Stutzerimonas stutzeri S1T11 standing out regarding high aerial and root length, as well as fresh and dry weight. This research study is one of the few studies on endophytic bacteria associated with the Morisonia scabrida tree. It demonstrates that its bacterial diversity could contribute to various biological roles, such as that of plant growth promoter under heat stress.
Lactic acid bacteria (LAB) are promising oral drug delivery systems due to their probiotic properties, safety, and ability to stimulate mucosal immunity. In this study, we characterized five LAB strains, Lacticaseibacillus casei ATCC 393, Lacticaseibacillus paracasei UST1611, Lactiplantibacillus plantarum UST1611, Limosilactobacillus reuteri LR08, and Lacticaseibacillus rhamnosus GG, to assess their potential as a microbial chassis for oral drug delivery. We tested competence for transformation, plasmid stability, GFP expression under a constitutive promoter, survival under simulated gastrointestinal conditions, and survival in the gut of Danio rerio larvae. Successful transformation with the pTRKH3-ermGFP plasmid was achieved in L. casei ATCC 393, L. paracasei UST1611, and L. reuteri LR08. We also showed that the L. casei ATCC 393 strain had significantly higher protein expression than its L. paracasei UST1611 and L. reuteri LR08 counterparts. In the absence of selection, L. casei ATCC 393 and L. paracasei UST1611 retained their plasmid for 48 h. L. reuteri LR08 retained it for up to 72 h. The three transformed strains showed comparable tolerance to simulated gastrointestinal pH, though L. casei and L. reuteri were more resistant to 0.3% greater bile. In vivo testing showed the highest survival for L. casei ATCC 393 and L. paracasei UST1611 in the gut of zebrafish (Danio rerio) larvae. Overall, our results suggest that, among the five strains tested, L. casei ATCC 393 is the most promising candidate for an LAB-based microbial system for oral drug delivery.
Endophytic bacteria from medicinal plants are increasingly recognized as sources of antimicrobial metabolites. However, the endophytic bacterial community of Mitrephora heyneana remains poorly explored. In the present study, endophytic bacteria were isolated from the leaves of M. heyneana, collected from the Western Ghats of Tamil Nadu, India. Among seven isolates, strain PEL6 was identified as Paenibacillus lactis through 16S rRNA gene sequencing. The ethyl acetate extract of PEL6 (EAE-PEL6) was subjected to gas chromatography-mass spectrometry (GC-MS) analysis, putatively identified 32 metabolites based on GC-MS library matching, including pyrrolo[1,2-a] pyrazine-1,4-dione derivatives and triazole compounds as major constituents. The EAE-PEL6 demonstrated significant in vitro antibacterial activity against Staphylococcus aureus. In silico ADMET (absorption, distribution, metabolism, excretion, and toxicity) profiling predicted drug-likeness and pharmacokinetic properties of selected candidate compounds. Molecular docking suggested favorable binding of selected metabolites to S. aureus target proteins; however, these interactions require experimental validation. Density Functional Theory calculations indicated that CID 70504 had the lowest Highest Occupied Molecular Orbital (HOMO)-Lowest Unoccupied Molecular Orbital (LUMO) energy gap, reflecting higher electronic reactivity. Molecular electrostatic potential mapping further supported its enhanced binding propensity. Molecular dynamics simulations suggested structural stability, with Root Mean Square Deviation, Solvent Accessible Surface Area, radius of gyration, and hydrogen-bond analyses indicating stable interactions throughout the 100 ns trajectory. Overall, this study identifies P. lactis PEL6 as a promising endophytic source of anti-S. aureus metabolites and provides candidates for future purification, structural confirmation, and biological validation.
The skin microbiome is essential for epidermal barrier integrity and immune homeostasis. This review explores the therapeutic shift in dermo-cosmetics toward probiotic, prebiotic, synbiotic, and postbiotic strategies for managing wound healing, “inflammaging”, and chronic dermatoses like acne, atopic dermatitis (AD), psoriasis, and rosacea. Mechanisms include gut–skin axis modulation, competitive pathogen exclusion, and the suppression of inflammatory pathways (e.g., NF-κB). While live probiotics demonstrate high clinical efficacy, their formulation is severely hindered by standard cosmetic preservatives and manufacturing thermal stress. Consequently, evidence suggests inanimate postbiotics have emerged as promising, stable alternatives, which may offer antimicrobial and tissue-repairing benefits without strict cold-chain requirements. However, the industry faces significant regulatory ambiguity and “probiotic-washing”, with most commercial products mislabeling postbiotic lysates as live cultures. Advancing this field requires standardized sampling protocols and transparent labeling. Ultimately, precision dermatology is likely to be driven by AI-assisted microbiome profiling, synthetic biology, and advanced delivery matrices (e.g., electrospun nanofibers, alginate microencapsulation), transforming skincare from reactive treatments into proactive, targeted ecological management.
Diseases caused by Fusarium spp. vary around the world. It is important to determine the causals agents and indigenous antagonists against these pathogens. Thus, this study aimed to (i) determine the pathogens of root rot and yellow leaf disease (RRYLD), (ii) select Trichoderma spp. strains to control the pathogens, and (iii) evaluate methods for preparing the antagonistic fungi. Diseased soil samples were collected from pomelo orchards in Ben Tre province, Vietnam. The experiment isolated 08 Fusarium spp. strains, with the fastest growth in PDA in FP-C16, FP-B18, FP-B16, and FP-B03 (8.33–17.3 mm) on day 4 of culture. They were identified as Fusarium fujikuroi FP-C16, F. verticillioides FP-B18, F. verticillioides FP-B16, and F. incarnatum FP-B03. On the other hand, 25 Trichoderma spp. strains were isolated from the pomelo rhizosphere. Among them, 13 Trichoderma spp. strains showed rapid growth and strong antagonistic activity against two Fusarium spp. strains under laboratory conditions. The two Trichoderma spp. strains TP-C40 and TP-G50 had antagonistic efficiencies against FP-C16 and FP-B16 at 47.7–63.5%. The two selected Trichoderma spp. strains were identified as Trichoderma asperellum TP-C40 and T. yunnanense TP-G50. The two Trichoderma spp. strains TP-C40 and TP-G50 reduced the number of leaves and roots infected by Fusarium spp.
Clostridium butyricum is a well-known Gram-positive, spore-forming, obligate anaerobic, and butyrate-producing bacterium with a few species of next-generation probiotic strains. By far, the most well-known strain is Clostridium butyricum CBM588 (also known as MIYAIRI 588). This strain has gained significant attention for its therapeutic potential across a variety of human health conditions. Preclinical studies have shown its ability to stabilize gut microbiota, enhance short-chain fatty acid (SCFA) production, and modulate immune responses, which contribute to its therapeutic effects in conditions such as ulcerative colitis, allergies, and cancer. We examined 28 interventional clinical trials and 7 observational studies investigating the effect of Clostridium butyricum strains. These studies have supported the findings of preclinical trials and demonstrated symptom improvement and immune modulation in diverse conditions. Clostridium butyricum CBM588 has shown efficacy in managing gastrointestinal diseases, such as acute gastroenteritis and inflammatory bowel disease, and has also proven beneficial in immune modulation, as evidenced by its positive effects in allergic rhinitis and cancer immunotherapy. Additionally, CBM588 has been reported to have a favorable safety and tolerability profile in various patient populations, including children, adults, and critically ill patients. Despite these promising results, clinical studies face limitations such as small sample sizes, varied protocols, and short study durations. Future well-designed, large-scale trials are necessary to further validate the long-term safety and efficacy of Clostridium butyricum in clinical practice.
Traditional fermented dairy products represent an important source of autochthonous microorganisms with potential applications in food biotechnology. This study aimed to isolate and characterize microorganisms from the traditional Kazakh fermented product kurt collected from different regions of the Abai area (Kazakhstan) and to evaluate their suitability for biotechnological applications in meat processing. Microbial isolation was performed using MRS medium under anaerobic conditions, followed by morphological and physiological characterization. Accurate identification was carried out using MALDI-TOF MS and 16S rRNA gene sequencing. The results showed that microbial counts ranged from 106 to 108 CFU/g, confirming high microbial diversity of kurt. MALDI-TOF MS analysis revealed the presence of Pichia fermentans, Enterococcus faecalis, Leuconostoc mesenteroides, and Lactobacillus helveticus, indicating that MRS medium supports the growth of both lactic acid bacteria and accompanying microbiota. Subsequent molecular analysis confirmed Leuconostoc mesenteroides and Lactobacillus helveticus as the most promising strains. These isolates demonstrated tolerance to salt, acidic conditions, and mesophilic temperatures, which are essential for meat fermentation processes. In contrast, Enterococcus faecalis was excluded from further application due to potential safety concerns. Overall, the study demonstrates that kurt is a valuable source of technologically important microorganisms and that the identified strains (Leuconostoc mesenteroides and Lactobacillus helveticus) are promising candidates for the development of starter cultures for fermented goat meat processing.
Antimicrobial resistance (AMR) has become one of the top ten global public health threats. Many countries have recognized the societal and economic burden of AMR. AMR has reduced the effectiveness of antimicrobial therapies, and this results in high mortality, morbidity, and health care expenditure. Like all the other developing countries, South Africa (SA) falls under the same ambiguous management system of antimicrobials. A lot of research focused on the global public health threat “AMR”. However, studies on AMR in wastewater are not yet enough, even though they are beginning to gain momentum. This paper highlights the imperatives of surveying AMR pathogens in wastewater since wastewaters are consecrated as hotspots for the dissemination and propagation of AMR genes. RNA was extracted from the untreated wastewater samples collected from the Tshwane district in Gauteng province, SA. Metatranscriptomics analysis was proposed for the analysis and profiling of AMR genes present in the wastewater. A total of 39 AMR gene families and 39 AMR drug classes were detected across 17 samples. The Metatranscriptomics approach discussed in this paper demonstrates the importance of wastewater surveillance, as it can be used as an early detecting system for communicable diseases and for monitoring wastewater.
Desert ecosystems harbor microbial communities adapted to extreme environmental conditions, including water scarcity, elevated temperatures, and intense UV radiation. Among these microorganisms, microalgae represent promising resources for agricultural applications. In this study, microalgae isolated from desert soils in Mexico were characterized by molecular (rbcL) and phylogenetic analysis, and morphological observations. They were identified as Chlorella sp. (RAD3), Nannochloris-related isolate (RAD4), and Chlorella cf. variabilis (RAD5). The effects of microalgal biomass on maize (Zea mays L.) germination and early seedling development were evaluated using a seed-priming approach. Microalgal treatments significantly improved (p < 0.05) germination-related traits, seedling vigor, shoot height, root length, and fresh and dry biomass, as compared with the control. Chlorella cf. variabilis (RAD5) was associated with reduced germination time, whereas Nannochloris-related isolate (RAD4) consistently produced the strongest responses in vigor and growth parameters. Although some variables reached their highest numerical values at 108 cells/mL, similar responses were usually observed at 107 cells/mL. Overall, the evaluated desert-derived microalgal preparations were associated with improved early maize seedling performance, under the evaluated conditions.
Klebsiella pneumoniae is a member of the six highly virulent and antibiotic-resistant bacterial pathogens group (ESKAPE) and poses a significant threat to public health due to its ability to cause both hospital and community-acquired infections. Recent health concerns have emerged about heat-tolerant bacterial contamination in hospital settings, particularly those associated with infant formula preparation. This study aims to evaluate the heat survival of 10 clinical K. pneumoniae strains in infant formula and to investigate the correlation between heat tolerance and the presence of heat shock resistance genes, particularly the clp family of ATPases. Ten strains of K. pneumoniae were exposed to heat at 55 °C for 30 min in infant formula. We assessed their survival rates and determined their D-values. Additionally, we screened for the presence of clpC family genes across representative strains. A wide variation in heat tolerance was observed among the strains. Strain 1701 (ST247, capsular antigen profile O3:K1) exhibited the highest heat tolerance, with a D-value of 12.9 min at 55 °C. The other strains exhibited moderate-to-low heat tolerance. Notably, strain 1701 was the only one that contained the clpC2 gene, suggesting a potential association between the clp gene family and heat resistance. Our results indicate that specific heat shock resistance genes, such as clpC2, may be associated with enhanced heat tolerance observed in K. pneumoniae strains. These findings highlight the potential role of heat shock proteins in bacterial persistence within neonatal healthcare environments.
The increasing demand for sustainable crop protection strategies has intensified interest in plant-beneficial bacteria as alternatives to synthetic agrochemicals. In this study, the soil-derived bacterium Pseudomonas putida V01 was isolated and characterized for its antifungal and plant growth-promoting potential through an integrated approach combining biological assays, untargeted metabolomics, and in vivo plant experiments. Cell-free culture filtrates exhibited strong antifungal activity against major phytopathogenic fungi, completely inhibiting the growth of Sclerotium rolfsii and significantly reducing mycelial development of Alternaria alternata and Fusarium proliferatum by 40% and 20%, respectively. Volatile organic compounds (VOCs) selectively inhibited Botrytis cinerea and A. alternata by 28% and 10%, respectively, and affected sporulation of F. proliferatum. Metabolomic profiling through LC-qTOF-MS and GC-MS analyses revealed a chemically diverse metabolome, including putatively annotated diketopiperazines, cyclic peptides, phenolic compounds, and fatty acids. VOC profiling indicated ketones and alcohols as the predominant volatile classes, with 2-undecanone and 2-undecanol among the most abundant compounds detected. In vivo assays on wheat seedlings showed significant increases in shoot growth, biomass accumulation, and chlorophyll content compared with untreated controls. These findings indicate that P. putida V01 combines complementary antifungal and plant growth-promoting activities associated with a diverse repertoire of diffusible and volatile metabolites. The integrated biological and metabolomic characterization highlights its potential as a multifunctional microbial inoculant for sustainable crop production and disease management.
The rapid emergence of multi-drug resistant (MDR) bacteria has become a major health concern, driving the need to identify new antimicrobial resources. Recently, endophytes, inhabiting in internal tissues of medicinal plants, have drew important interest from the scientific community, as reservoirs of bioactive metabolites. Numerous studies highlight the symbiotic relationship between plants and their endophytes, in which these microorganisms produce antimicrobial compounds, helping the host plant’s defense against pathogens. Plantago major (commonly known as plantain) is widely recognized for its therapeutic properties, especially for its antimicrobial properties. In this study, endophytic fungi were isolated from Plantago major, morphologically characterized and identified using ITS sequencing. Their antibacterial activity was assessed using the agar diffusion assay. In total, 21 endophytic fungal isolates were obtained from different plant tissues, including leaves, stems, roots, and flowers. Antibacterial assays against methicillin-resistant Staphylococcus aureus (MRSA) were investigated on PDA, SDA, and CDA media. Amongst the isolates, nine strains (MD-H1, MD-L1, MD-L2, MD-L3, MD-L4, MD-L5, MD-R1, MD-T1, MD-T2, and MD-T10) showed medium to strong antibacterial effects, with inhibition zones exceeding 15 mm. The result suggests that endophytic fungi associated with Plantago is a valuable source of anti-MRSA compounds. Further work will focus on identifying the secondary metabolites responsible for this activity and elucidating their chemical structures, providing a basis for the development of new potent antibiotic agents.
Helicobacter pylori is a highly prevalent pathogen associated with chronic gastritis, peptic ulcers, and gastric cancer. Treatment is increasingly challenging due to antibiotic resistance and adverse effects that can reduce adherence. These limitations have encouraged the exploration of complementary strategies. This study evaluated the in vitro antibacterial activity of selected probiotic strains and synbiotic formulations containing inulin against clinical isolates of H. pylori. Isolates obtained from gastric biopsies were identified by MALDI-TOF. Four probiotic strains (Lacticaseibacillus casei, Lacticaseibacillus rhamnosus, Limosilactobacillus fermentum, and Streptococcus thermophilus) were tested individually and as a mixed culture, both alone and combined with inulin. Antibacterial activity was assessed using the agar well diffusion method under microaerophilic conditions after 72 h of incubation at 37 °C. Variable inhibitory effects were observed, with L. fermentum (8.08 ± 1.98 mm) and the probiotic mixture (7.92 ± 0.90 mm) showing greater activity, while S. thermophilus exhibited limited inhibition. The addition of low-dose inulin (3 mg/mL) was associated with increased inhibition by the probiotic mixture (9.58 ± 1.51 mm), whereas higher concentrations did not enhance this effect. These findings indicate that certain probiotic and synbiotic formulations exhibit in vitro activity against H. pylori and warrant further investigation as complementary approaches.
