Appl. Microbiol., Volume 5, Issue 3 (September 2025) – 34 articles

Pathogenic bacteria have developed different ways to cause infections. One strategy involves using components from host cells. This study looks at the role of the cytoskeleton in the human colon adenocarcinoma Caco-2 and neonatal non-transformed epithelial H4 cell lines during bacterial invasion. The bacteria studied include Cronobacter malonaticus, Cronobacter sakazakii, and E. coli K1, as they are associated with known diseases. Salmonella enteritidis 358 served as a positive control and E. coli K12 as a negative control for the invasion experiments. Before the invasion experiments, cell lines were treated with microfilament inhibitors, specifically Cytochalasin D, and microtubule inhibitors, such as Colchicine, Nocodazole, Vinblastine, and Taxol. The results showed that Cytochalasin D reduced about 60–80% of Cronobacter invasion into H4 cells and 50% of E. coli K1 invasion. In contrast, Colchicine reduced the invasion of some strains to just 2% compared to untreated cells. Meanwhile, Nocodazole and Taxol increased the invasion of C. sakazakii 709 and C. malonaticus 1569 into H4 cells by about 140% and 160%, respectively, while slightly inhibiting other strains. In Caco-2 cells, certain strains exhibited increased invasion due to Cytochalasin D, Vinblastine, and Colchicine treatment. This led to increases of up to 500%, 227%, and 248% compared to untreated cells. However, Nocodazole and Taxol decreased invasion into Caco-2 cells, with only E. coli K1 showing an increase of about 150% in Taxol-treated cells. The findings with eukaryotic cytoskeleton inhibitors on neonatal H4 cells suggest that bacterial invasion mainly relies on microfilaments or microfilament-dependent. No specific dependence on the cytoskeleton was seen in Caco-2 cells. In conclusion, cytoskeletal inhibitors significantly affected bacterial invasion, specifically Cronobacter, compared to untreated cells. This suggests that invasion methods may vary by strain and are influenced by how each inhibitor alters cytoskeleton behavior. Therefore, the invasion process, both with and without cytoskeletal inhibitors, is crucial for understanding how bacteria manipulate cell components during infection. Full article

In the case of a notifiable animal disease like salmonellosis, manure is contaminated and must be disinfected. This can be performed using heat measures, chemical disinfectants, or long-term storage. All these measures bring along severe economic, ecological, and logistical problems. The aim of this study was to evaluate lactic acid fermentation (LAF) as an alternative disinfection method. Fermentation was started by adding a carbohydrate source to the manure and creating anaerobic conditions. For testing, cattle manure was enriched with different carbohydrate (CHO) sources and spiked with Salmonella Typhimurium (S. Ty.). The samples were incubated at 10 °C and 21 °C for 111 days (Exp1) and at 21 °C for 50 days (Exp2). The microbial shift was determined using cultural methods and MALDI-TOF. Both the change in pH and Enterococcus spp. were tested as suitable indicators. The results showed the different suitability of the selected CHO for hygienization by LAF. Using squeezed oat as an additive, S. Ty was reduced to below the detection limit under both temperature conditions within 21 days and 14 days. Additional saccharose decreased the reduction time. This study showed that LAF is a valuable alternative for disinfecting cattle manure in the case of bovine salmonellosis. Using this method, both manure and feed residues can be treated in one approach and afterwards be used as fertilizer. Full article

Escherichia coli O157:H7 has been an important foodborne pathogen causing severe disease in humans worldwide. It is challenging to control E. coli O157:H7 due to its intrinsic acid resistance, ability to survive in various environments, and the emergence of antimicrobial resistance. Recent research showed that phages are promising antibacterial agents. A phage (Φ241) infecting 48 E. coli O157:H7 strains from various sources was previously isolated from an industrial cucumber fermentation at pH 3.7 and 5% NaCl. The efficacy of phage Φ241 infection was evaluated in this study in four representative model food systems (beef broth, cucumber juice, cucumber juice supplemented with NaCl, and apple juice). Pronounced differences in phage effectiveness were found in the tested food systems, and impacted by pH, salinity, and multiplicity of infection. The potential of this phage is evident in beef broth and cucumber juice, where 4- to 6-log reduction in host concentration was achieved within 3 to 5 h. However, apple juice (pH 3.55) completely inhibited host growth and phage infection. Overall, the study shows the high potential of Φ241 as an antibacterial agent to improve food safety. Future research will incorporate a cocktail of phages targeting E. coli O157:H7 to mitigate phage resistance development. Full article

Coffee pulp, the primary residue generated during the wet processing of Coffea arabica L., is frequently applied directly to fields as a crude soil amendment. However, this practice often lacks proper microbial stabilization, limiting its agronomic potential and posing risks due to the presence of phytotoxic compounds. In Colombia, disease-resistant varieties such as Coffea arabica L. var. Castillo and var. Cenicafé 1, developed by the National Coffee Research Center (Cenicafé), are the amongst the most widely cultivated varieties in the country; however, despite their widespread adoption, the microbial ecology of postharvest residues from these varieties remains poorly characterized. This study aimed to isolate and functionally characterize native microbial communities from the pulp of Coffea arabica var. Castillo and var. Cenicafé 1, and to evaluate their role in postharvest processing and organic waste management. Fresh pulp samples were collected from a wet-processing facility located in tropical mid-elevation zones. A total of 53 microbial isolates were recovered using culture-dependent techniques on selective media targeting yeasts, lactic acid bacteria (LAB), and filamentous fungi. Amplicon sequencing of the 16S rRNA gene (V3–V4 region) and ITS1 region was conducted to profile bacterial and fungal communities, revealing diverse microbial consortia dominated by Aspergillus, Lactobacillus, Leuconostoc, Pichia, and Saccharomyces species. Enzymatic screening indicated high pectinolytic and cellulolytic activity. Composting trials using inoculated pulp showed a ~40% reduction in composting time and improved nutrient content. These findings support the use of native microbiota to enhance composting efficiency and postharvest valorization, contributing to more sustainable and circular coffee systems. Full article

Myxobacteria, a group of swarming, predatory soil bacteria, are of interest because of their biocontrol potential. In this study, the inhibitory effects of 13 strains of myxobacteria were examined against four different phytopathogenic fungi, as follows: two isolates of Rhizoctonia solani from different AG groups and one isolate each from Sclerotinia sclerotiorum and the oomycete Pythium ultimum. Inhibition levels varied among phytopathogens, with slow-growers being more susceptible than fast-growers. Myxococcus xanthus BS 248, M. flavus ATCC 29617, and M. coralloides BS249 were the most inhibitory strains tested. non-contact and contact inhibition on agar media between phytopathogens and myxobacteria were visually discernible. This distinction potentially reflects the activity of low-molecular-weight metabolites and high-molecular-weight lytic enzymes, respectively. In a pot soil study, the inhibitory effect of a mixture of two strains of myxobacteria against two strains of R. solani was apparent from the reduced disease in cucumber seedlings compared to controls without myxobacteria. This is the first report of an in vivo inhibitory effect of myxobacteria against Rhizoctonia. The survival of M. xanthus BS248 in sterile soil amended with rabbit manure (1:1) increased up to five weeks compared to one week in soil without the manure, suggesting that organic amendment could enrich myxobacteria in soil. Full article

Microbial metabolites offer a multitude of mechanisms for alleviating diabetes, particularly type 2 diabetes (T2D). However, the metabolites of yeasts recognised as safe remain under-explored and are receiving less attention in the treatment of T2D. In addition to the recognised probiotic status of certain yeasts, their genetic feature is responsible for many of the effects observed. Branched and non-branched short-chain fatty acids, bioactive peptides, carotenoids, and polysaccharides (β-glucans, mannans, and peptides derived from them) have vital properties that modulate intestinal permeability, soothe inflammation, and directly influence insulin sensitivity. Their action mechanism ranges from hepatic lipogenesis via the induction of hormone-sensitive lipase and the inhibition of α-glucosidase or DPP-IV to promoting the secretion of GLP-1 (Glucagon-Like Peptide-1) and GIP (Gastric Inhibitory Polypeptide), orchestrating immune modulation, and nourishing the gut microbiota. The richness of the yeast metabolome suggests that a concentrated fermentate could be developed to potentiate the functional effects in vitro in the treatment of T2D. The purpose of this review is to take stock of the current state of knowledge of probiotic yeast metabolites and outline their potential for the treatment of diabetes via the development of food supplements or nutraceuticals. Full article

Veterinary vaccines are essential tools for controlling infectious and zoonotic diseases, safeguarding animal welfare, and ensuring global food security. However, conventional vaccines are hindered by cold-chain dependence, thermal instability, and logistical challenges, particularly in low- and middle-income countries (LMICs). This review explores next-generation veterinary vaccines, emphasizing innovations in thermostability and delivery platforms to overcome these barriers. Recent advances in vaccine drying technologies, such as lyophilization and spray drying, have improved antigen stability and storage resilience, facilitating effective immunization in remote settings. Additionally, novel delivery systems, including nanoparticle-based formulations, microneedles, and mucosal routes (intranasal, aerosol, and oral), enhance vaccine efficacy, targeting immune responses at mucosal surfaces while minimizing invasiveness and cost. These approaches reduce reliance on cold-chain logistics, improve vaccine uptake, and enable large-scale deployment in field conditions. The integration of thermostable formulations with innovative delivery technologies offers scalable solutions to immunize livestock and aquatic species against major pathogens. Moreover, these strategies contribute significantly to One Health objectives by mitigating zoonotic spillovers, reducing antibiotic reliance, and supporting sustainable development through improved animal productivity. The emerging role of artificial intelligence (AI) in vaccine design—facilitating epitope prediction, formulation optimization, and rapid diagnostics—further accelerates vaccine innovation, particularly in resource-constrained environments. Collectively, the convergence of thermostability, advanced delivery systems, and AI-driven tools represents a transformative shift in veterinary vaccinology, with profound implications for public health, food systems, and global pandemic preparedness. Full article

Due to its high bioconversion efficiency and nutritional value, the black soldier fly (Hermetia illucens L. 1758) is a promising insect species for sustainable animal feed production. However, concerns remain regarding microbial safety when larvae are reared on substrates contaminated by pathogenic or spoilage bacteria. This study investigated the effects of substrate inoculation with Bacillus subtilis 168 or Pseudomonas putida KT2440 on larval performance and gut microbiota composition. Larvae reared on contaminated diets showed no significant differences in survival or development time compared to controls. However, a short-term reduction in growth was observed in the Bacillus-exposed group. qPCR analyses confirmed the temporary presence of Bacillus taxa in larval guts, while Pseudomonas taxa were effectively excluded. Amplicon sequencing of the 16S rRNA gene revealed that the contamination did not affect gut bacterial microbiota richness and composition. Instead, the bacterial communities evolved naturally with Lactobacillales-related bacteria dominating early stages and Morganellaceae taxa becoming more abundant in prepupae. Our findings demonstrate the stability and resilience of H. illucens gut bacterial microbiota, reinforcing the safety and suitability of H. illucens as a feed ingredient, even when reared under challenging microbial conditions. Full article

Salmonella is a zoonotic foodborne pathogen that affects poultry health and reaches consumers through the food chain via contaminated products. A cross-sectional study was conducted to isolate and identify Salmonella and to detect antibiotic resistance genes in Salmonella isolates from retail meat shops in Chitwan, Nepal. The antimicrobial susceptibility test was carried out using the Kirby–Bauer disc diffusion method. Antibiotic resistance genes were detected by using multiplex polymerase chain reaction (PCR). A total of 216 samples, chicken meat (108) and water (108), were tested for the presence of Salmonella. Out of the 216 samples tested, 38 samples were positive, giving an overall prevalence of 17.59%. A higher prevalence of Salmonella was found in meat samples, 29.62% (32/108), compared with the water samples, 5.55% (6/108), which was statistically significant (p < 0.05). The antibiogram profile showed maximum resistance to doxycycline (88%), followed by tetracycline (86%), erythromycin (79%), ampicillin + sulbactam (76%), ceftriaxone (22%), levofloxacin (21%), gentamicin (18%), chloramphenicol (13%), and amikacin (15%). The prevalence of the tetB gene and ere(A) gene was 23.68% (9/38) and 18.42% (7/38), respectively, and the association was statistically non-significant (p > 0.05). However, mcr1, catA1, and blaTEM genes were not detected. The study recommends integrated surveillance encompassing human health, food safety, and animal health under the ‘One Health’ approach, highlighting the need for effective strategies involving poultry farms, retail meat shops, and consumers to minimize contamination and reduce the transmission of Salmonella along the food chain from primary production to consumption on a global scale. Full article

Foodborne illness caused by bacterial pathogens is a global health concern and results in millions of infections annually. Therefore, food products typically undergo several processing stages, including sanitation steps, before being distributed in an attempt to remove pathogens. However, many sanitation methods have compounding effects on the color, texture, flavor, and nutritional quality of the product or do not effectively reduce the pathogens that food can be exposed to. Some bacterial pathogens particularly possess traits and tactics that make them even more difficult to mitigate such as biofilm formation. Non-thermal plasma sanitation techniques, including plasma-treated water (PTW), have proven to be promising methods that significantly reduce pathogenic bacteria that food is exposed to. Published work reveals that PTW can effectively mitigate both gram-positive and gram-negative bacterial biofilms. This study presents a novel analysis of the differences in antimicrobial effects of PTW treatment between biofilm-forming gram-positive bacteria, commonly associated with foodborne illness, that are sporulating (Bacillus cereus) and non-sporulating (Listeria monocytogenes). After treatment with PTW, the results suggest the following hypotheses: (1) that the non-sporulating species experiences less membrane damage but a greater reduction in metabolic activity, leading to a possible viable but non-culturable (VBNC) state, and (2) that the sporulating species undergoes spore formation, which may subsequently convert into vegetative cells over time. PTW treatment on gram-positive bacterial biofilms that persist in food processing environments proves to be effective in reducing the proliferating abilities of the bacteria. However, the variance in PTW’s effects on metabolic activity and cell vitality between sporulating and non-sporulating species suggest that other survival tactics might be induced. This analysis further informs the application of PTW in food processing as an effective sanitation method. Full article

Heavy metal pollution represents a pervasive environmental challenge that significantly exacerbates the ever-increasing crisis of antimicrobial resistance and the capacity of microorganisms to endure and proliferate despite antibiotic interventions. This review examines the intricate relationship between heavy metals and AMR, with an emphasis on the underlying molecular mechanisms and ecological ramifications. Common environmental metals, including arsenic, mercury, cadmium, and lead, exert substantial selective pressures on microbial communities. These induce oxidative stress and DNA damage, potentially leading to mutations that enhance antibiotic resistance. Key microbial responses include the overexpression of efflux pumps that expel both metals and antibiotics, production of detoxifying enzymes, and formation of protective biofilms, all of which contribute to the emergence of multidrug-resistant strains. In the soil environment, particularly the rhizosphere, heavy metals disrupt plant–microbe interactions by inhibiting beneficial organisms, such as rhizobacteria, mycorrhizal fungi, and actinomycetes, thereby impairing nutrient cycling and plant health. Nonetheless, certain microbial consortia can tolerate and detoxify heavy metals through sequestration and biotransformation, rendering them valuable for bioremediation. Advances in biotechnology, including gene editing and the development of engineered metal-resistant microbes, offer promising solutions for mitigating the spread of metal-driven AMR and restoring ecological balance. By understanding the interplay between metal pollution and microbial resistance, we can more effectively devise strategies for environmental protection and public health. Full article

Background: Developments in biology, genetics, soil science, plant breeding, engineering, and agricultural microbiology are driving advances in soil microbiology and microbial biotechnology. Material and methods: The literature for this review was collected by searching leading scientific databases such as Embase, Medline/PubMed, Scopus, and Web of Science. Results: Recent advances in soil microbiology and biotechnology are discussed, emphasizing the role of microorganisms in sustainable agriculture. It has been shown that soil and plant microbiomes significantly contribute to improving soil fertility and plant and soil health. Microbes promote plant growth through various mechanisms, including potassium, phosphorus, and zinc solubilization, biological nitrogen fixation, production of ammonia, HCN, siderophores, and other secondary metabolites with antagonistic effects. The diversity of microbiomes related to crops, plant protection, and the environment is analyzed, as well as their role in improving food quality, especially under stress conditions. Particular attention was paid to the diversity of microbiomes and their mechanisms supporting plant growth and soil fertility. Conclusions: The key role of soil microorganisms in sustainable agriculture was highlighted. They can support the production of natural substances used as plant protection products, as well as biopesticides, bioregulators, or biofertilizers. Microbial biotechnology also offers potential in the production of sustainable chemicals, such as biofuels or biodegradable plastics (PHA) from plant sugars, and in the production of pharmaceuticals, including antibiotics, hormones, or enzymes. Full article

Sustainability represents a significant global challenge, requiring a balance between environmental impact and the use of natural resources. White biotechnology, which uses microorganisms and enzymes for environmentally friendly products and processes, offers promising solutions to support a growing population. Within this context, the yeast Yarrowia lipolytica stands out, so we investigated the generation of biomass from two wild strains (ATCC 9773 and NRRL Y-50997) using different carbon sources. Additionally, protein content and amino acid profiles were assessed via standardized analytical methods to evaluate their potential as nutritional yeasts. Both strains demonstrated potential as nutritional yeasts, with biomass productivities of up to 35.5 g/L and 42 g/L, respectively. The protein content was high, with 58.8% for ATCC 9773 and 58.2% for NRRL Y-50997. Furthermore, the strains presented essential amino acid contents of 62.6% and 41.5%, with lysine being the most abundant amino acid. These findings underscore the versatility and productivity of Y. lipolytica, highlighting its potential for sustainable biotechnological applications such as single-cell protein production. Full article

The study aimed to identify potential sources of novel probiotic yeasts exhibiting health-promoting properties. A combination of metabarcoding analysis and cultural methods was employed to investigate and isolate yeasts from various sources, including rice wine, palm wine, fermented shrimp paste at different stages of natural fermentation, and lychee peels. The two analytical methods revealed distinct yeast profiles, and each source exhibited a unique composition of yeast species. Through metabarcoding and cultural methods, it was demonstrated that lychee peels harbored a greater diversity of genera compared to other sources. The evaluation of the probiotic properties of yeasts revealed that lychee peel yielded the highest proportion of isolates with potential probiotic activity (53.33%), followed by palm wine (25%), fermented shrimp paste (10%), and rice wine (9.09%). Moreover, yeast isolates with health-promoting properties as evaluated in this study, including Starmerella meliponinorum L12 and Pichia terricola L9 from lychee peels, demonstrated notable antioxidant activity and cholesterol-reducing properties, respectively. These findings represent the first report providing initial insights into the influence of yeast sources and serve as a guideline for the targeted selection of yeasts with specific probiotic and health-promoting attributes. Full article

This study aimed to evaluate the production of xylose reductase (XR), an enzyme responsible for converting xylose into xylitol, by Candida tropicalis ATCC 750 using hemicellulosic hydrolysate from cashew apple bagasse (CABHM) as a low-cost carbon source. The effects of temperature, aeration, and fluid dynamics on XR biosynthesis were also investigated. The highest XR production (1.53 U mL⁻¹) was achieved at 30 °C, with 8.3 g·L⁻¹ of xylitol produced by the yeast under microaerobic conditions, demonstrating that aeration and fluid dynamics are important factors in this process. Cellular metabolism and enzyme production decreased at temperatures above 35 °C. The maximum enzymatic activity was observed at pH 7.0 and 50 °C. XR is a heterodimeric protein with a molecular mass of approximately 30 kDa. These results indicate that CABHM is a promising substrate for XR production by C. tropicalis, contributing to the development of enzymatic bioprocesses for xylitol production from lignocellulosic biomass. This study also demonstrates the potential of agro-industrial residues as sustainable feedstocks in biorefineries, aligning with the principles of a circular bioeconomy. 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

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

Myocardial infarction (MI) is an inflammatory disease responsible for approximately 75% of sudden cardiac deaths. In this study, we aimed to evaluate the cardio-protective influence of microencapsulated probiotic and synbiotic dietary supplements in vivo and in molecular docking studies. MI was induced in rats with the injection of isoproterenol (i.p. 67 mg/kg). Plasma lipid profiles and the levels of oxidative stress markers, inflammatory markers, and cardiac enzymes were determined. The expression levels of MMP-7 and IL-1β in the heart muscle were measured. The impact of dietary supplements on fecal bacterial counts was evaluated across all rat groups. A histopathological examination of cardiac tissue was performed. The cardio-protective potential of cyanidin 3-diglucoside 5-glucoside and arabinoxylan was studied using molecular docking. The results demonstrate that all tested dietary supplements induced an improvement in all the biochemical parameters in association with an improvement in myocardial muscle tissue. The mRNA expression levels of MMP-7 and IL-1β were significantly downregulated by all dietary supplements. All dietary supplements increased the fecal counts of probiotic strains. In the molecular docking analysis, cyanidin 3-diglucoside 5-glucoside exhibited binding affinity values of −8.8 and −10 for lactate dehydrogenase (LDH) and Paraoxonase 1 (PON1), respectively. Arabinoxylan showed similar binding affinity (−8.8) for both LDH and PON1. Conclusion: Microencapsulated probiotic and synbiotic dietary supplements demonstrated notable cardio-protective influence in vivo and in molecular docking studies. These supplements may serve as promising candidates for the prevention of myocardial infarction. Full article

A fungal strain with comparably high chitosan yield was isolated from the Shivaganga hills and identified as Aspergillus versicolor AD07 through molecular characterization. Later, the strain was cultivated on Sabouraud Dextrose Broth (SDB) and wild jackfruit-based media to evaluate its potential for chitosan production. Among the various media formulations, the highest chitosan yield (178.40 ± 1.76 mg/L) was obtained from the jackfruit extract medium with added peptone and dextrose. The extracted chitosan was characterized through FTIR, XRD (reported a crystallinity index of 55%), TGA/DTG, and DSC analysis, confirming the presence of key functional groups and high thermal resistance. The extracted chitosan was fabricated into a sheet incorporated with 1% lemongrass oil; the sheet exhibited strong antibacterial activity against Escherichia coli (30 mm) and Bacillus megaterium (48 mm). The biodegradation studies reported a weight loss of 38.93 ± 0.51% after 50 days of soil burial. Further, the chitosan film was tested as a packaging material for paneer, demonstrating better preservation by maintaining nutritional quality and reducing microbial load over a 14-day storage period. These findings highlight the potential of A. versicolor AD07-derived chitosan, cultivated on a waste substrate medium, as a sustainable biopolymer for food packaging applications. Full article

Schizophrenia is a complex psychiatric disorder traditionally linked to neurotransmitter dysregulation, particularly within dopamine and glutamate pathways. However, recent evidence implicates the gut–brain axis as a potential contributor to its pathophysiology. This perspective article proposes a systems-level understanding of schizophrenia that incorporates the role of gut microbial dysbiosis specifically, reductions in short-chain fatty acid (SCFA)-producing taxa, and elevations in pro-inflammatory microbes. These imbalances may compromise gut barrier integrity, stimulate systemic inflammation, and disrupt neurochemical signaling in the brain. We synthesize findings from animal models, clinical cohorts, and microbial intervention trials, highlighting mechanisms such as SCFA regulation, altered tryptophan–kynurenine metabolism, and microbial impacts on neurotransmitters. We also explore microbiome-targeted interventions like probiotics, prebiotics, dietary strategies, and fecal microbiota transplantation (FMT) and their potential as adjunctive therapies. While challenges remain in causality and translation, integrating gut–brain axis insights may support more personalized and biologically informed models of schizophrenia care. Full article

Alkalihalophilus marmarensis is an obligate alkaliphile with exceptional tolerance to high-pH environments, making it a promising candidate for industrial bioprocesses that require contamination-resistant and extremophilic production platforms. However, its practical deployment is hindered by limited biomass formation under extreme conditions, which constrains overall productivity. This study presents a model-driven investigation of how pH (8.8 and 10.5), culture duration (24 and 48 h), and nitrogen source composition (peptone and meat extract) affect cell dry mass, lactate, and protease synthesis. Using the response surface methodology and multi-objective optimization, we established predictive models (R² up to 0.92) and uncovered key trade-offs in biomass and metabolite yields. Our findings reveal that peptone concentration critically shapes the metabolic output, with low levels inhibiting growth and high levels suppressing protease activity. Maximum cell dry mass (4.5 g/L), lactate (19.3 g/L), and protease activity (43.5 U/mL) were achieved under distinct conditions, highlighting the potential for targeted process tuning. While the model validation confirmed predictions for lactate, deviations in cell dry mass and protease outputs underscore the complexity of growth–product interdependencies under nutrient-limited regimes. This work delivers a foundational framework for developing fermentations with A. marmarensis and advancing its application in sustainable, high-pH industrial bioprocesses. The insights gained here can be further leveraged through synthetic biology and bioprocess engineering to fully exploit the metabolic potential of obligate alkaliphiles like A. marmarensis. Full article

Anaerobes, the oldest evolutionary life forms, have been unexplored for their potential to produce secondary metabolites due to the difficulties observed in their cultivation. Antimicrobials derived from anaerobic bacteria are an emerging and valuable source of novel therapeutic agents. The urgent need for new antimicrobial agents due to rising antibiotic resistance has prompted an investigation into anaerobic bacteria. The conventional method of antimicrobial discovery is based on cultivation and extraction methods. Antibacterial and antifungal substances are produced by anaerobic bacteria, but reports are limited due to oxygen-deficient growth requirements. The genome mining approach revealed the presence of biosynthetic gene clusters involved in various antimicrobial compound synthesis. Thus, the current review is focused on antimicrobials derived from anaerobes to unravel the potential of anaerobic bacteria as an emerging valuable source of therapeutic agents. These substances frequently consist of peptides, lipopeptides, and other secondary metabolites. Many of these antimicrobials have distinct modes of action that may be able to go around established resistance pathways. To this effect, we discuss diverse antimicrobial compounds produced by anaerobic bacteria, their biosynthesis, heterologous production, and activity. The findings suggest that anaerobic bacteria harbor significant biosynthetic potential, warranting further exploration through recombinant production for developing new antibiotics. Full article

This exploratory study presents the first metagenomic assessment of the gut microbiome in domestic cats from Cali, Colombia. Fecal samples were collected from 10 healthy, sterilized domestic cats, aged 8 months to over 2 years, with variation in sex (7 females, 3 males), diet (processed or raw), and outdoor access (5 with, 5 without). Using 16S rRNA gene metabarcoding and pooled shotgun metagenomic sequencing, the study characterized the taxonomic composition and functional potential of the feline gut microbiome. Dominant phyla included Bacillota and Bacteroidota, with substantial inter-individual variation. Peptoclostridium was the most consistently abundant genus, while Megamonas and Megasphaera showed higher variability. Shotgun analysis detected antibiotic resistance genes (ErmG, ErmQ) and virulence factors (pfoA, plc, colA, nanJ, nagI) in Clostridium perfringens, highlighting potential zoonotic risk. The composition of the gut microbiota was influenced primarily by diet and outdoor access, while age and gender had more moderate effects. The study concludes that lifestyle and environmental factors play a key role in shaping the gut microbiome of domestic cats. We recommend further longitudinal and larger-scale studies to better understand the dynamics of feline microbiota and their implications for animal and public health within a One Health framework. Full article

Fruit rot seriously damages pomelo production. Given concerns regarding the safety of chemical agents, biological alternatives are becoming more preferable. Therefore, the experiment aimed to (i) identify the pathogens causing pomelo fruit rot disease and (ii) select Trichoderma spp. strains controlling the determined pathogens in Ben Tre, Vietnam. Three pathogenic fungal strains isolated from diseased pomelo fruits were selected. The three pathogenic fungal strains were randomly injected into 9 healthy pomelo fruits. The strain PCP-B02-A2 led to a completely rotten fruit on day 17 after infection, while strains PCP-B02-B2 and PCP-B03-A1 had infected spots whose lengths were 17.5 and 28.1 mm, became larger, and eventually led to the whole fruit rot. The pathogens were identified by the internal transcribed spacer (ITS) technique as Colletotrichum gloeosporioides PCP-B02-A2, Pseudopestalotiopsis camelliae sinensis PCP-B03-A1, and P. chinensis PCP-B02-B2. Twenty-five Trichoderma spp. strains were isolated. The ITS technique identified four strains, including Trichoderma asperellum TP-B01, T. harzianum TP-B08, T. harzianum TP-B09, and T. asperellum TP-C25. The PCP-B02-A2 strain had antagonism at 66.7–68.7%, while those of PCP-B02-B2 and PCP-B03-A1 were 64.2–71.1% and 55.7–57.4%, respectively. Full article

Cheese ripening involves microbial changes, with starter lactic acid bacteria (SLAB) initiating fermentation and nonstarter lactic acid bacteria (NSLAB) driving flavor and texture development. However, heat-resistant spores of Clostridium and Bacillus can survive pasteurization and cause spoilage during ripening. This study evaluated NSLAB dynamics in the presence of spores during cheese ripening. Cheddar cheese samples at pilot-scale level (110 L) with four treatments, namely control, with spores of B. licheniformis (T1), with spores of Cl. tyrobutyricum (T2), and both spores (T3) at 2.0 Log₁₀ CFU/mL, were ripened at 7 °C for six months. SLAB declined from 8.0 to 0.2 Log₁₀ CFU/g, while NSLAB increased from 2.0 to 8.5 Log₁₀ CFU/g by month three and maintained their counts up to six months, unaffected by spore presence. Spore counts were ≤1.45 Log₁₀ CFU/g in controls but reached 2.94 ± 0.02 (T2) and 2.48 ± 0.03 (T3), correlating with spoilage signs after five months. MALDI-TOF identified L. rhamnosus (up to 37%) and L. paracasei (up to 25%) as dominant NSLAB across treatments. Physicochemical parameters were not significantly affected by higher spore levels. While NSLAB dominated, they were inadequate to prevent spoilage in spore-inoculated samples exceeding 2.0 logs during cheese ripening. Full article

A key feature that differentiates Gram-positive and Gram-negative bacteria is the outer membrane, an asymmetric membrane composed of lipopolysaccharides, phospholipids, lipoproteins and integral proteins, including the outer-membrane proteins (OMPs). By being in direct contact with the extracellular milieu, the outer membrane and OMPs participate in multiple functions in Gram-negative bacteria, including controlling nutrient and molecule access to the cytoplasm, membrane vesicle formation and resistance to environmental stresses. OMPs have a characteristic barrel shape formed by antiparallel β-strands, with or without channels that allow diffusion of substrates through the outer membrane. The marine bacterium Vibrio cholerae is responsible for non-invasive gastroenteritis and cholera disease by consumption of contaminated water or food. Its OMPs, besides having a porin function, contribute to resistance to osmotic pressure and antimicrobial agents, intracellular signaling, adhesion to host cells and biofilm formation, amongst other functions. In this review, in addition to quickly reviewing the general structure of the outer membrane, the OMPs and how they reach the outer membrane, the functions attributed to these proteins are compiled. The mechanisms used by each of the described OMP to accomplish these functions in the marine pathogenic bacterium V. cholerae are discussed. Potential clinical and bioengineering applications of OMPs, such as diagnostic tools, vaccine development, and targeted antimicrobial or anti-virulence strategies are presented. What is known about the OMPs of V. cholerae is presented below. Full article

Antimicrobial use in food animals selects for antimicrobial-resistant (AMR) bacteria, which most commonly reach humans via the food chain. However, AMR bacteria can also escape the feedyard via agricultural runoff, manure used as crop fertilizer, and even dust. A study published in 2015 reported AMR genes in dust from cattle feedyards; however, one of the study’s major limitations was the failure to investigate gene presence in viable bacteria, or more importantly, viable bacteria of importance to human health. Our main objective was to investigate the presence and quantity of viable bacteria and antimicrobial-resistant (AMR) determinants in fugitive bioaerosols from cattle feedyards in the downwind environment. Six bioaerosol sampling campaigns were conducted at three commercial beef cattle feedyards to assess variability in viable bacteria and AMR determinants associated with geographic location, meteorological conditions, and season. Dust samples were collected using four different sampling methods, and spiral plated in triplicate on both non-selective and antibiotic-selective media. Colonies of total aerobic bacteria, Enterococcus spp., Salmonella enterica, and Escherichia coli were enumerated. Viable bacteria, including AMR bacteria, were identified in dust from cattle feedyards. Bacteria and antimicrobial resistance genes (ARGs via qPCR) were mainly found in downwind samples. Total suspended particles (TSPs) and impinger samples yielded the highest bacterial counts. Genes encoding beta-lactam resistance (bla_CMY-2 and bla_CTX-M) were detected while the most common ARG was tet(M). The predominant Salmonella serovar identified was Lubbock. Further research is needed to assess how far viable AMR bacteria can travel in the ambient environment downwind from cattle feedyards, to model potential public health risks. Full article

The EAT-Lancet diet is an outstanding model of a healthy, environmentally sustainable diet. However, its effects on the gut microbiota remain poorly explored. This study assessed the asso-ciation between adherence to the EAT-Lancet diet in habitual intake and the relative abundance of selected gut bacteria in a Mexican subpopulation. Fifty-four young adults (18–35 years) completed a validated Food Frequency Questionnaire (FFQ) and were nutritionally assessed. Participants were grouped into low, moderate, and high adherence levels to the EAT-Lancet diet. Blood samples were analysed for glucose and lipid profiles, and gDNA from faecal samples was analysed using Real-time qPCR to quantify gut bacteria. While no significant differences in bacterial abundance were observed across adherence levels, correlations emerged with increased adherence. Notably, Bifidobacterium negatively correlated with beef and lamb intake (rho −0.5, p < 0.05), and Akkermansia muciniphila negatively correlated with fish intake (rho −0.8, p < 0.05). Bilophila wadsworthia positively correlated with triglycerides, while Prevotella copri and Faecalibacterium prausnitzii negatively correlated with body fat and blood pressure, respectively. In addition, a non-significant trend toward a higher abundance of Firmicutes, Akkermansia muciniphila, and Prevotella copri was observed in the high-adherence group, whereas Lactobacillus tended to be more abundant in participants with low and moderate adherence. These findings suggest that adherence to the EAT-Lancet diet modulates gut microbiota composition. However, further controlled interventional studies are needed to confirm these effects and their implications for human health. Full article

The growing threat of antibiotic-resistant Gram-negative bacteria highlights the urgent need for innovative, non-bactericidal therapeutic strategies. Quorum-sensing (QS) inhibition has emerged as a promising approach to attenuate bacterial virulence without exerting selective pressure. This study evaluated the antimicrobial, anti-QS, and antibiofilm properties of aqueous extracts from five medicinal plants native to northeastern Mexico: Gymnosperma glutinosum, Ibervillea sonorae, Larrea tridentata, Olea europaea, and Tecoma stans. Disk diffusion and violacein quantification assays using Chromobacterium violaceum demonstrated significant QS inhibition by G. glutinosum and T. stans, with violacein reductions of 60.02% and 52.72%, respectively, at 40 mg/mL. While L. tridentata and O. europaea exhibited antibacterial activity, I. sonorae showed no growth or pigment inhibition but achieved the highest biofilm disruption (89.89%) against Salmonella typhimurium. UPLC-MS analysis identified chlorogenic acid, kaempferol, and D-(−)-quinic acid as major constituents, compounds previously associated with QS modulation. These findings highlight the potential of traditional Mexican plant species as sources of QS inhibitors and bio-film-disrupting agents, supporting their further development as alternatives to conventional antibiotics. Full article

The whole-genome sequencing of lactic acid bacteria provides a valuable resource for identifying the genetic determinants underlying molecular mechanisms related to their probiotic properties. Analysis of draft genome sequences relies on bioinformatics tools for genetic data processing and in silico analytical methods to pinpoint the genetic determinants encoding biologically active compounds. The aim of this study was to perform the phenotypic determination of the antibiotic sensitivity and bioinformatics analyses on whole-genome assemblies from LAB from the human oral microbiome, and determine the presence of acquired antibiotic resistance genes, peptidases, adhesion proteins, and bacteriocins. Bioinformatics processing was performed in order to establish the molecular mechanisms responsible for the previously observed probiotic properties. The tested LAB strains exhibited a broad spectrum of antibiotic multiresistance, but did not possess acquired antibiotic resistance genes. The detected genes for peptidase activity were from the Pep family of hydrolase enzymes. Genetic determinants for adhesion proteins contained LPxTG, YSIRK, KxYKxGKxW, and SEC 10/PgrA domains, as well as MucBP domains. Lectins were found for five of the strains with the presence of WxL domains from the CscC protein family and L-type lectin domains. The in silico analyses show that some of the tested strains possessed mechanisms for bacteriocin production. Full article