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International Journal of Molecular... Aug 2021is an opportunistic, psychotropic pathogen that can live in different environments, such as plant, soil, or water surfaces, and it is associated with food spoilage....
is an opportunistic, psychotropic pathogen that can live in different environments, such as plant, soil, or water surfaces, and it is associated with food spoilage. Bioactive compounds can be used as antimicrobials and can be added into packaging systems. Quercetin and lactoferrin are the best candidates for the development of a complex of the two molecules absorbed on bio combability structure as hydroxyapatite. The minimum inhibiting concentration (MIC) of single components and of the complex dropped down the single MIC value against Characterization analysis of the complex was performed by means SEM and zeta-potential analysis. Then, the synergistic activity () of single components and the complex was calculated. Finally, the synergistic activity was confirmed, testing in vitro its anti-inflammatory activity on U937 macrophage-like human cell line. In conclusion, the peculiarity of our study consists of optimizing the specific propriety of each component: the affinity of lactoferrin for LPS; that of quercetin for the bacterial membrane. These proprieties make the complex a good candidate in food industry as antimicrobial compounds, and as functional food.
Topics: Anti-Bacterial Agents; Anti-Infective Agents; Cells, Cultured; Dose-Response Relationship, Drug; Drug Synergism; Durapatite; Humans; Lactoferrin; Nanoparticles; Pseudomonas Infections; Pseudomonas fluorescens; Quercetin; U937 Cells
PubMed: 34502150
DOI: 10.3390/ijms22179247 -
Saudi Journal of Biological Sciences Aug 2021Carrot is a vital supply of dietary fiber, vitamins, and carotenoids, and it is also rich in antioxidants and minerals. Soil salinity significantly reduces the yield and...
Carrot is a vital supply of dietary fiber, vitamins, and carotenoids, and it is also rich in antioxidants and minerals. Soil salinity significantly reduces the yield and quality of carrots. Mycorrhiza inoculum (AMF) is known to improve morphological and biochemical traits of vegetables even under saline conditions. But the role of AMF in combating soil salinity effect in carrot is not studied in detail. Therefore here, in the first set, carrot seeds are inoculated with microbes in a pot experiment under polyhouse condition. In total, we applied 7 treatments with different combinations of Mycorrhiza inoculum ( (G) and (G)) and phosphate solubilizing bacteria ( (P)). In pot experiment study the best two treatments were the combination of G + P + G and P + G. Both of these treatments were selected for validation under the open field conditions. Primarily, there seems to be a promising opportunity for AMF application to carrots under pot culture as well as under field trials because of promising effect towards morphological parameters, especially root weight, and disparities in nutrients and metabolites. Overall, our study highlights mycorrhizal fungi and other microbes' efficacy in achieving a successful carrot production under salinity stress.
PubMed: 34354402
DOI: 10.1016/j.sjbs.2021.06.025 -
World Journal of Microbiology &... Dec 2022Pseudomonas fluorescens is considered among the main spoilage microorganisms due to its ability to produce proteases. Food deterioration caused by spoilage...
Pseudomonas fluorescens is considered among the main spoilage microorganisms due to its ability to produce proteases. Food deterioration caused by spoilage microorganisms has a major impact on food quality and the environment. The inactivation of Pseudomonas fluorescens growth and protease production was intensively investigated with the use of Salmide®, A Sodium Chlorite-Based Oxy-halogen Disinfectant. A unique M9 media was also developed to assure sufficient protease productions with different mutants of Pseudomonas fluorescens as a microbioreactor. Mutations were induced by classical whole-cell mutagenesis using N-methyl-N'- nitro-N-nitrosoguanidine (NTG). A dramatic decrease occurred in protease activity when different Salmide concentrations (5, 10, and 15 ppm) were added to the growth culture followed by a complete inhibition concentration (20, 25, 50, and 100 ppm) of Salmide. However, no significant inhibition occurred once it is secreted out of cells. Some mutants were resistant and remains highly stable with high protease production under stressful conditions of Sodium Chlorite-Based Oxy-halogen. The production of the protease showed a linear correlation with the increase in incubation time using a continuous culture bioreactor system and recorded maximum protease activity after 40 h. Our findings would offer alternative antimicrobial procedures for food and industrial sectors.
Topics: Pseudomonas fluorescens; Endopeptidases; Peptide Hydrolases; Halogens
PubMed: 36469174
DOI: 10.1007/s11274-022-03471-6 -
Journal of Medical Microbiology Mar 2020Metabolism is the foundation of all living organisms and is at the core of numerous if not all biological processes. The ability of an organism to modulate its... (Review)
Review
Metabolism is the foundation of all living organisms and is at the core of numerous if not all biological processes. The ability of an organism to modulate its metabolism is a central characteristic needed to proliferate, to be dormant and to survive any assault. is bestowed with a uniquely versatile metabolic framework that enables the microbe to adapt to a wide range of conditions including disparate nutrients and toxins. In this mini-review we elaborate on the various metabolic reconfigurations evoked by this microbial system to combat reactive oxygen/nitrogen species and metal stress. The fine-tuning of the NADH/NADPH homeostasis coupled with the production of α-keto-acids and ATP allows for the maintenance of a reductive intracellular milieu. The metabolic networks propelling the synthesis of metabolites like oxalate and aspartate are critical to keep toxic metals at bay. The biochemical processes resulting from these defensive mechanisms provide molecular clues to thwart infectious microbes and reveal elegant pathways to generate value-added products.
Topics: Adenosine Triphosphate; Aspartic Acid; Homeostasis; Metabolic Networks and Pathways; Metals; NAD; NADP; Oxalates; Oxidation-Reduction; Oxidative Stress; Pseudomonas fluorescens; Reactive Oxygen Species; Stress, Physiological
PubMed: 31961786
DOI: 10.1099/jmm.0.001139 -
Brazilian Journal of Biology = Revista... 2022Pseudomonas fluorescens is one of the main causes of septicemic diseases among freshwater fish, causing severe economic losses and decreasing farm efficiency. Thus, this...
Pseudomonas fluorescens is one of the main causes of septicemic diseases among freshwater fish, causing severe economic losses and decreasing farm efficiency. Thus, this research was aimed to investigate the occurrence of P. fluorescens in Nile Tilapia (O. niloticus) fish in Egypt, gene sequencing of 16SrDNA gene, and antimicrobial susceptibility. P. fluorescens strains were detected in 32% (128\400) of apparently healthy (9%; 36\400) and diseased (23%; 92\400) Nile tilapia fish. The highest prevalence was observed in gills of fish, 31.3% followed by intestine 26.9%, liver 24.2%, and kidneys 17.6%. The PCR results for the 16SrDNA gene of P. fluorescens showed 16SrDNA gene in 30% of examined isolates. Moreover, Homogeny and a strong relationship between strains of P. fluorescens was confirmed using 16SrDNA sequences. Beside the responsibility of 16SrDNA gene on the virulence of P. fluorescens. The results of antimicrobial susceptibility tests revealed that all strains were resistant to piperacillin (100%), followed by ceftazidime (29.7%), and cefepime (25.8%). The strains of P. fluorescence were highly sensitive to cefotaxime (74.2%), followed by ceftriaxone and levofloxacin (70.3% each). Interestingly, 29.7% of strains of P. fluorescens were multiple antimicrobial-resistant (MAR).
Topics: Animals; Anti-Bacterial Agents; Cichlids; Drug Resistance, Bacterial; Egypt; Pseudomonas fluorescens
PubMed: 35293547
DOI: 10.1590/1519-6984.257144 -
Bioresource Technology Aug 2023The ammonium and nitrate removal performance and metabolic pathways of a biocontrol strain, Pseudomonas fluorescens 2P24, were investigated. Strain 2P24 could completely...
The ammonium and nitrate removal performance and metabolic pathways of a biocontrol strain, Pseudomonas fluorescens 2P24, were investigated. Strain 2P24 could completely remove 100 mg/L ammonium and nitrate, with removal rates of 8.27 mg/L/h and 4.29 mg/L/h, respectively. During these processes, most of the ammonium and nitrate were converted to biological nitrogen via assimilation, and only small amounts of nitrous oxide escaped. The inhibitor allylthiourea had no impact on ammonium transformation, and diethyl dithiocarbamate and sodium tungstate did not inhibit nitrate removal. Intracellular nitrate and ammonium were detectable during the nitrate and ammonium transformation process, respectively. Moreover, the nitrogen metabolism functional genes (glnK, nasA, narG, nirBD, nxrAB, nirS, nirK, and norB) were identified in the strain. All results highlighted that P. fluorescens 2P24 is capable of assimilatory and dissimilatory nitrate reduction, ammonium assimilation and oxidation, and denitrification.
Topics: Nitrates; Ammonium Compounds; Pseudomonas fluorescens; Denitrification; Nitrogen; Metabolic Networks and Pathways
PubMed: 37196744
DOI: 10.1016/j.biortech.2023.129189 -
Microbiology Spectrum Aug 2022Drought is one of the most vulnerable factors that affect crop productivity. Little is known about plant-associated microbiomes and their functional roles in assisting...
Drought is one of the most vulnerable factors that affect crop productivity. Little is known about plant-associated microbiomes and their functional roles in assisting plant growth under drought. We investigated the genetic and transcriptomic characteristics of opportunistic beneficial microorganisms that selectively alleviate stress through plant-bacteria interactions under drought. Pseudomonas fluorescens DR397 was isolated from the drought-prone rhizospheric soil of soybean and showed high metabolic activity at -1.25 Mpa. The genome of DR397 possesses several genes related to the synthesis of compatible solutes (choline and glycine-betaine), exopolysaccharides (alginate and cellulose), and secretion systems (type II, III, IV, and VI), as well as genes related to plant growth promotion (indole-3-acetic acid, transketolase, and thiamine phosphate synthesis). The expression of these genes was significantly upregulated (8- to 263-fold change) only under drought conditions with plant root exudate treatment, whereas subtle transcriptomic changes were observed under solely root exudate treatment. When DR397 was placed on both legume cultivars (Pisum sativum and Phaseolus vulgaris), growth was hardly affected under well-watered conditions, but the shoot and root growths were increased by up from 62.0% to 149.1% compared with the control group under drought conditions. These results provide fundamental insight on the plant-bacterial interactions that alleviate plant stress as an important ecological strategy for improving drought tolerance. Drought is a serious abiotic stress on plants as wells as the microbes that coexist with plants, which significantly lowers their fitness. The plant-bacterial interaction is an important strategy to enhance their fitness under drought. However, many knowledge gaps still exist in our understanding of transcriptomic features of bacteria interacting with plant under drought. Here, by investigating the transcriptomic profiles and pot cultivation with legume, we show that the interactions of Pseudomonas fluorescens DR397 with plants change with drought. We, therefore, provide a fundamental evidence of a hidden hero in the soil that promote plant fitness from external stress.
Topics: Droughts; Nerve Growth Factors; Plant Roots; Plants; Pseudomonas fluorescens; Soil; Stress, Physiological
PubMed: 35863006
DOI: 10.1128/spectrum.00979-22 -
Heliyon Nov 2022The application of soil beneficial bacteria (SBB) in agriculture is steadily increasing as it provides a promising way to replace chemical fertilisers and other...
The application of soil beneficial bacteria (SBB) in agriculture is steadily increasing as it provides a promising way to replace chemical fertilisers and other supplements. Although the role of SBB as a biofertiliser is well understood, little is known about the response of soil physiochemical properties via the change in soil enzymatic activities with SBB growth. In this study, sterilised bulk soil was inoculated with (BS) and (PF), which exhibit excellent characteristics for potentially improving soil quality. It is found that the contents of bioavailable nitrogen and ammonium in soil inoculated with SBB increased significantly, up to 34% and 57% relative to a control. This resulted from the enhancement of soil urease activity with BS and PF treatments by approximately 90% and 70%, respectively. The increased soil urease activity can be explained by the increased microorganism activity evident from the larger population size of BS (0.78-0.97 CFU mL/CFU mL) than PF (0.55-0.79 CFU mL/CFU mL) ( < 0.05). Results of principal component analysis also reinforce the interaction apparent in the significant relationship between soil urease activity and microbial biomass carbon ( < 0.05). Therefore, it can be concluded that the enhancement of soil enzymatic activities induced bulk soil fertility upregulation because of bacterial growth. These results demonstrate the application of SBB to be a promising strategy for bulk soil amendment, particularly nutrient restoration.
PubMed: 36439778
DOI: 10.1016/j.heliyon.2022.e11674 -
Frontiers in Microbiology 2021In this study, linalool, one of the principal components of essential oils, was used as an antibacterial agent to investigate the antibacterial activity and mechanism of...
In this study, linalool, one of the principal components of essential oils, was used as an antibacterial agent to investigate the antibacterial activity and mechanism of linalool against The reduction in membrane potential (MP), leakage of alkaline phosphatase (AKP) and the release of macromolecules, including DNA, RNA and protein confirmed that damage to cell wall membrane structure and leakage of cytoplasmic contents were due to the linalool treatment. Furthermore, the decrease of enzyme activity, including the succinate dehydrogenase (SDH), malate dehydrogenase (MDH), pyruvate kinase (PK), and ATPase indicated that linalool could lead to metabolic dysfunction and inhibit energy synthesis. In addition, the activity of respiratory chain dehydrogenase and metabolic activity of respiration indicated that linalool inhibits cellular respiration. These results revealed that linalool had strong antibacterial activity against via membrane damage, bacterial metabolic and oxidative respiratory perturbations, interfering in cellular functions and even causing cell death. It was suggested that linalool may be a new potential source as food antiseptics in food systems.
PubMed: 33584604
DOI: 10.3389/fmicb.2021.562094 -
Corner Flows Induced by Surfactant-Producing Bacteria Bacillus subtilis and Pseudomonas fluorescens.Microbiology Spectrum Oct 2022A mechanistic understanding of bacterial spreading in soil, which has both air and water in angular pore spaces, is critical to control pathogenic contamination of soil...
A mechanistic understanding of bacterial spreading in soil, which has both air and water in angular pore spaces, is critical to control pathogenic contamination of soil and to design bioremediation projects. A recent study (J. Q. Yang, J. E. Sanfilippo, N. Abbasi, Z. Gitai, et al., Proc Natl Acad Sci U S A 118:e2111060118, 2021, https://doi.org/10.1073/pnas.2111060118) shows that Pseudomonas aeruginosa can self-generate flows along sharp corners by producing rhamnolipids, a type of biosurfactants that change the hydrophobicity of solid surfaces. We hypothesize that other types of biosurfactants and biosurfactant-producing bacteria can also generate corner flows. Here, we first demonstrate that rhamnolipids and surfactin, biosurfactants with different chemical structures, can generate corner flows. We identify the critical concentrations of these two biosurfactants to generate corner flow. Second, we demonstrate that two common soil bacteria, Pseudomonas fluorescens and Bacillus subtilis (which produce rhamnolipids and surfactin, respectively), can generate corner flows along sharp corners at the speed of several millimeters per hour. We further show that a surfactin-deficient mutant of B. subtilis cannot generate corner flow. Third, we show that, similar to the finding for P. aeruginosa, the critical corner angle for P. fluorescens and B. subtilis to generate corner flows can be predicted from classic corner flow theories. Finally, we show that the height of corner flows is limited by the roundness of corners. Our results suggest that biosurfactant-induced corner flows are prevalent in soil and should be considered in the modeling and prediction of bacterial spreading in soil. The critical biosurfactant concentrations we identify and the mathematical models we propose will provide a theoretical foundation for future predictions of bacterial spreading in soil. The spread of bacteria in soil is critical in soil biogeochemical cycles, soil and groundwater contamination, and the efficiency of soil-based bioremediation projects. However, the mechanistic understanding of bacterial spreading in soil remains incomplete due to a lack of direct observations. Here, we simulate confined spaces of hydrocarbon-covered soil using a transparent material with similar hydrophobicity and visualize the spread of two common soil bacteria, Pseudomonas fluorescens and Bacillus subtilis. We show that both bacteria can generate corner flows at the velocity of several millimeters per hour by producing biosurfactants, soap-like chemicals. We provide quantitative equations to predict the critical corner angle for bacterial corner flow and the maximum distance of the corner spreading. We anticipate that bacterial corner flow is prevalent because biosurfactant-producing bacteria and angular pores are common in soil. Our results will help improve predictions of bacterial spreading in soil and facilitate the design of soil-related bioremediation projects.
Topics: Bacillus subtilis; Surface-Active Agents; Pseudomonas fluorescens; Soaps; Soil Microbiology; Pseudomonas aeruginosa; Soil; Water
PubMed: 36214703
DOI: 10.1128/spectrum.03233-22