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Foods (Basel, Switzerland) Jan 2024In the food industry, foodborne spoilage bacteria often live in mixed species and attach to each other, leading to changes in spoilage characteristics. Quorum sensing...
In the food industry, foodborne spoilage bacteria often live in mixed species and attach to each other, leading to changes in spoilage characteristics. Quorum sensing (QS) has been reported to be a regulating mechanism for food spoiling by certain kinds of bacteria. Here, the contents of biofilm, extracellular polysaccharides, and biogenic amines in the coculture system of H4 and ATCC13525 were significantly reduced when the QS element of H4 was deleted, confirming that QS of H4 is involved in the dual-species interactions. Then, transcriptomics was used to explore the regulatory mechanism at the mRNA molecular level. The deletion of the QS element decreased the transcript levels of genes related to chemotaxis, flagellar assembly, and the two-component system pathway of H4 in the coculture system. Furthermore, a total of 732 DEGs of ATCC13525 were regulated in the dual species, which were primarily concerned with biofilm formation, ATP-binding cassette transporters, and amino acid metabolism. Taken together, the absence of the QS element of H4 weakened the mutual cooperation of the two bacteria in the coculture system, making it a good target for managing infection with and .
PubMed: 38275703
DOI: 10.3390/foods13020336 -
PLoS Biology Jan 2024Ecological variation influences the character of many biotic interactions, but examples of predator-prey reversal mediated by abiotic context are few. We show that the...
Ecological variation influences the character of many biotic interactions, but examples of predator-prey reversal mediated by abiotic context are few. We show that the temperature at which prey grow before interacting with a bacterial predator can determine the very direction of predation, reversing predator and prey identities. While Pseudomonas fluorescens reared at 32°C was extensively killed by the generalist predator Myxococcus xanthus, P. fluorescens reared at 22°C became the predator, slaughtering M. xanthus to extinction and growing on its remains. Beyond M. xanthus, diffusible molecules in P. fluorescens supernatant also killed 2 other phylogenetically distant species among several examined. Our results suggest that the sign of lethal microbial antagonisms may often change across abiotic gradients in natural microbial communities, with important ecological and evolutionary implications. They also suggest that a larger proportion of microbial warfare results in predation-the killing and consumption of organisms-than is generally recognized.
Topics: Animals; Predatory Behavior; Antibiosis; Biological Evolution; Microbiota; Myxococcus xanthus
PubMed: 38261596
DOI: 10.1371/journal.pbio.3002454 -
Frontiers in Microbiology 2023Microbiome engineering is an emerging research field that aims to design an artificial microbiome and modulate its function. In particular, subtractive modification of...
Microbiome engineering is an emerging research field that aims to design an artificial microbiome and modulate its function. In particular, subtractive modification of the microbiome allows us to create an artificial microbiome without the microorganism of interest and to evaluate its functions and interactions with other constituent bacteria. However, few techniques that can specifically remove only a single species from a large number of microorganisms and can be applied universally to a variety of microorganisms have been developed. Antisense peptide nucleic acid (PNA) is a potent designable antimicrobial agent that can be delivered into microbial cells by conjugating with a cell-penetrating peptide (CPP). Here, we tested the efficacy of the conjugate of CPP and PNA (CPP-PNA) as microbiome modifiers. The addition of CPP-PNA specifically inhibited the growth of and in an artificial bacterial consortium comprising , , , and . Moreover, the growth inhibition of promoted the growth of and inhibited the growth of . These results indicate that CPP-PNA can be used not only for precise microbiome engineering but also for analyzing the growth relationships among constituent microorganisms in the microbiome.
PubMed: 38260881
DOI: 10.3389/fmicb.2023.1321428 -
Molecules (Basel, Switzerland) Jan 2024Microbial community succession in raw milk determines its quality and storage period. In this study, carbon dioxide (CO) at 2000 ppm was used to treat raw milk to...
Microbial community succession in raw milk determines its quality and storage period. In this study, carbon dioxide (CO) at 2000 ppm was used to treat raw milk to investigate the mechanism of extending the shelf life of raw milk by CO treatment from the viewpoint of microbial colonies and metabolites. The results showed that the shelf life of CO-treated raw milk was extended to 16 days at 4 °C, while that of the control raw milk was only 6 days. Microbiomics analysis identified 221 amplicon sequence variants (ASVs) in raw milk, and the alpha diversity of microbial communities increased ( < 0.05) with the extension of storage time. Among them, , and were the major microbial genera responsible for the deterioration of raw milk, with a percentage of 85.7%. A combined metagenomics and metabolomics analysis revealed that microorganisms altered the levels of metabolites, such as pyruvic acid, glutamic acid, 5'-cmp, arginine, 2-propenoic acid and phenylalanine, in the raw milk through metabolic activities, such as ABC transporters, pyrimidine metabolism, arginine and proline metabolism and phenylalanine metabolism, and reduced the shelf life of raw milk. CO treatment prolonged the shelf life of raw milk by inhibiting the growth of Gram-negative aerobic bacteria, such as , , and .
Topics: Animals; Carbon Dioxide; Milk; Metabolomics; Arginine; Phenylalanine
PubMed: 38257241
DOI: 10.3390/molecules29020329 -
Scientific Reports Jan 2024The interactions between microbes and plants are governed by complex chemical signals, which can forcefully affect plant growth and development. Here, to understand how...
The interactions between microbes and plants are governed by complex chemical signals, which can forcefully affect plant growth and development. Here, to understand how microbes influence Houttuynia cordata Thunb. plant growth and its secondary metabolite through chemical signals, we established the interaction between single bacteria and a plant. We inoculated H. cordata seedlings with bacteria isolated from their roots. The results showed that the total fresh weight, the total dry weight, and the number of lateral roots per seedling in the P. fluorescens-inoculated seedlings were 174%, 172% and 227% higher than in the control seedlings. Pseudomonas fluorescens had a significant promotional effect of the volatile contents compared to control, with β-myrcene increasing by 192%, 2-undecanone by 203%, decanol by 304%, β-caryophyllene by 197%, α-pinene by 281%, bornyl acetate by 157%, γ-terpinene by 239% and 3-tetradecane by 328% in P. fluorescens-inoculated H. cordata seedlings. the contents of chlorogenic acid, rutin, quercitin, and afzelin were 284%, 154%, 137%, and 213% higher than in control seedlings, respectively. Our study provided basic data to assess the linkages between endophytic bacteria, plant phenotype and metabolites of H. cordata to provide an insight into P. fluorescens use as biological fertilizer, promoting the synthesis of medicinal plant compounds.
Topics: Houttuynia; Pseudomonas fluorescens; Plant Extracts; Plants, Medicinal; Drugs, Chinese Herbal
PubMed: 38243055
DOI: 10.1038/s41598-024-52070-y -
Biofilm Jun 2024This study investigates the potential of using bacteriophages to control foodborne pathogen biofilms on stainless steel surfaces in the food industry. Biofilm-forming...
This study investigates the potential of using bacteriophages to control foodborne pathogen biofilms on stainless steel surfaces in the food industry. Biofilm-forming bacteria can attach to stainless steel surfaces, rendering them difficult to eradicate even after a thorough cleaning and sanitizing procedures. Bacteriophages have been proposed as a possible solution, as they can penetrate biofilms and destroy bacterial cells within, reducing the number of viable bacteria and preventing the growth and spread of biofilms. This systematic review and meta-analysis evaluates the potential of bacteriophages against different biofilm-forming foodborne bacteria, including , , , , and . Bacteriophage treatment generally causes a significant average reduction of 38 % in biofilm formation of foodborne pathogens on stainless steel. Subgroup analyses revealed that phages are more efficient in long-duration treatment. Also, applying a cocktail of phages is 1.26-fold more effective than applying individual phages. Phages at concentrations exceeding 10 PFU/ml are significantly more efficacious in eradicating bacteria within a biofilm. The antibacterial phage activity decreases substantially by 3.54-fold when applied at 4 °C compared to temperatures above 25 °C. This analysis suggests that bacteriophages can be a promising solution for controlling biofilms in the food industry.
PubMed: 38234712
DOI: 10.1016/j.bioflm.2023.100170 -
Scientific Reports Jan 2024Lipopeptides, derived from microorganisms, are promising surface-active compounds known as biosurfactants. However, the high production costs of biosurfactants,...
Lipopeptides, derived from microorganisms, are promising surface-active compounds known as biosurfactants. However, the high production costs of biosurfactants, associated with expensive culture media and purification processes, limit widespread industrial application. To enhance the sustainability of biosurfactant production, researchers have explored cost-effective substrates. In this study, crude glycerol was evaluated as a promising and economical carbon source in viscosinamide production by Pseudomonas fluorescens DR54. Optimization studies using the Box - Behnken design and response surface methodology were performed. Optimal conditions for viscosinamide production including glycerol 70.8 g/L, leucine 2.7 g/L, phosphate 3.7 g/L, and urea 9.3 g/L were identified. Yield of viscosinamide production, performed under optimal conditions, reached 7.18 ± 0.17 g/L. Preliminary characterization of viscosinamide involved the measurement of surface tension. The critical micelle concentration of lipopeptide was determined to be 5 mg/L. Furthermore, the interactions between the viscosinamide and lipase from Candida rugosa (CRL) were investigated by evaluating the impact of viscosinamide on lipase activity and measuring circular dichroism. It was observed that the α-helicity of CRL increases with increasing viscosinamide concentration, while the random coil structure decreases.
Topics: Pseudomonas fluorescens; Glycerol; Surface-Active Agents; Lipopeptides; Lipase; Peptides, Cyclic
PubMed: 38233450
DOI: 10.1038/s41598-024-51179-4 -
International Journal of Infectious... Mar 2024Pseudomonas fluorescens (P. fluorescens) is not generally considered a bacterial pathogen in humans; however, multiple culture-based and culture-independent studies have...
Pseudomonas fluorescens (P. fluorescens) is not generally considered a bacterial pathogen in humans; however, multiple culture-based and culture-independent studies have identified it in the indigenous microbiota of multiple body sites. We herein report a rare case of pneumonia caused by P. fluorescens. A man in his 80 s with chronic obstructive pulmonary disease and diabetes mellitus was diagnosed with stage II rectal cancer. He underwent laparoscopic surgery, and on the 6th postoperative day, he developed a high fever. Chest computed tomography revealed infiltration in the left lower lung. Gram staining of the sputum showed Gram-negative rods phagocytosed by neutrophils, suggesting postoperative nosocomial pneumonia. The patient was started on tazobactam/piperacillin, and his pneumonia quickly improved. Later, only P. fluorescens was detected in a sputum culture. It was susceptible to common antipseudomonal agents. Gram staining of P. fluorescens appears to show a slightly thicker and larger morphology in comparison to Pseudomonas aeruginosa. Although there have been reports of opportunistic infections caused by P. fluorescens in immunosuppressed patients, including those with advanced cancer, most have been bloodstream infections, with very few reports of pneumonia alone. Clinicians should be aware that patients, who are not necessarily immunosuppressed, may develop pneumonia caused by P. fluorescens.
Topics: Male; Humans; Pseudomonas fluorescens; Pseudomonas Infections; Pneumonia; Pneumonia, Bacterial; Piperacillin, Tazobactam Drug Combination; Pseudomonas aeruginosa; Anti-Bacterial Agents
PubMed: 38218379
DOI: 10.1016/j.ijid.2024.01.007 -
EFSA Journal. European Food Safety... Jan 2024The food enzyme phosphoinositide phospholipase C (1-phosphatidyl-1D-myo-inositol-4,5-bisphosphate inositoltrisphosphohydrolase EC 3.1.4.11.) is produced with the...
The food enzyme phosphoinositide phospholipase C (1-phosphatidyl-1D-myo-inositol-4,5-bisphosphate inositoltrisphosphohydrolase EC 3.1.4.11.) is produced with the genetically modified strain PIC by DSM Food specialties B.V. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used in the processing of fats and oils for the production of refined edible fats and oils by degumming. Since residual amounts of the total organic solids are removed by the washing and purification steps applied during degumming, dietary exposure estimation and toxicity testing were considered unnecessary. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no matches were found. The Panel considered that the risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood for this to occur is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.
PubMed: 38213417
DOI: 10.2903/j.efsa.2024.8513 -
Scientific Reports Jan 2024There has recently been an explosion of studies implicating the human microbiome in playing a critical role in many disease and wellness states. The etiology of abnormal... (Observational Study)
Observational Study
There has recently been an explosion of studies implicating the human microbiome in playing a critical role in many disease and wellness states. The etiology of abnormal semen analysis (SA) parameters is not identified in 30% of cases; investigations involving the semen microbiome may bridge this gap. Here, we explore the relationship between the semen microbiome and alterations of sperm parameters. We recruited men presenting for fertility evaluation or vasectomy consultation with proven biological paternity. SA and next generation sequencing was performed. Differential abundance testing using Analysis of composition of Microbiota with Bias Correction (ANCOM-BC) was performed along with canonical correlational analysis for microbial community profiling. Men with abnormal (N = 27) sperm motility showed a higher abundance of Lactobacillus iners compared to those with normal (N = 46) sperm motility (mean proportion 9.4% versus 2.6%, p = 0.046). This relationship persisted on canonical correlational analysis (r = 0.392, p = 0.011). Men with abnormal sperm concentration (N = 20) showed a higher abundance of Pseudomonas stutzeri (2.1% versus 1.0%, p = 0.024) and Pseudomonas fluorescens (0.9% versus 0.7%, p = 0.010), but a lower abundance of Pseudomonas putida (0.5% versus 0.8%, p = 0.020), compared to those with normal sperm concentration (N = 53). Major limitations are related to study design (cross-sectional, observational). Our results suggest that a small group of microorganisms may play a critical role in observed perturbations of SA parameters. Some of these microbes, most notably Lactobacillus iners, have been described extensively within other, fertility-related, contexts, whereas for others, this is the first report where they have potentially been implicated. Advances in our understanding of the semen microbiome may contribute to potentially new therapeutic avenues for correcting impairments in sperm parameters and improving male fertility.
Topics: Humans; Male; Cross-Sectional Studies; Fertility; Infertility, Male; Lactobacillus; Semen; Semen Analysis; Sperm Count; Sperm Motility; Spermatozoa
PubMed: 38212576
DOI: 10.1038/s41598-024-51686-4