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Molecules (Basel, Switzerland) Jun 2024In this study, hybrid skeleton material ZIF-8@ZIF-67 was synthesized by the epitaxial growth method and then was utilized as a carrier for encapsulating lipase (PFL)...
In this study, hybrid skeleton material ZIF-8@ZIF-67 was synthesized by the epitaxial growth method and then was utilized as a carrier for encapsulating lipase (PFL) through the co-precipitation method, resulting in the preparation of immobilized lipase (PFL@ZIF-8@ZIF-67). Subsequently, it was further treated with glutaraldehyde to improve protein immobilization yield. Under optimal immobilization conditions, the specific hydrolytic activity of PFL@ZIF-8@ZIF-67 was 20.4 times higher than that of the free PFL. The prepared biocatalyst was characterized and analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR). Additionally, the thermal stability of PFL@ZIF-8@ZIF-67 at 50 °C was significantly improved compared to the free PFL. After 7 weeks at room temperature, PFL@ZIF-8@ZIF-67 retained 78% of the transesterification activity, while the free enzyme was only 29%. Finally, PFL@ZIF-8@ZIF-67 was applied to the neryl acetate preparation in a solvent-free system, and the yield of neryl acetate reached 99% after 3 h of reaction. After 10 repetitions, the yields of neryl acetate catalyzed by PFL@ZIF-8@ZIF-67 and the free PFL were 80% and 43%, respectively.
Topics: Enzymes, Immobilized; Pseudomonas fluorescens; Lipase; Esterification; Enzyme Stability; Zeolites; Spectroscopy, Fourier Transform Infrared; Temperature; Acetates; X-Ray Diffraction; Biocatalysis; Imidazoles
PubMed: 38930986
DOI: 10.3390/molecules29122922 -
Antioxidants (Basel, Switzerland) Jun 2024This study explored, for the first time, the chemical composition and in vitro antioxidant and antibacterial activities of a caper leaf essential oil (EO) emulsion for...
This study explored, for the first time, the chemical composition and in vitro antioxidant and antibacterial activities of a caper leaf essential oil (EO) emulsion for possible food applications as a natural preservative. The EO was extracted by hydrodistillation from the leaves of growing wild in the Aeolian Archipelago (Sicily, Italy) and exhibited a pungent, sulphurous odour. The volatile fraction of the emulsion, analysed by SPME-GC-MS, consisted of over 100 compounds and was dominated by compounds with recognised antibacterial and antioxidant properties, namely dimethyl tetrasulfide (18.41%), dimethyl trisulfide (12.58%), methyl isothiocyanate (7.97%), and terpinen-4-ol (6.76%). The emulsion was effective against all bacterial strains tested (, , , subsp. enterica serovar Enteritidis, ), with exhibiting the lowest minimum inhibitory concentration (MIC = 0.02 mg/mL) while had the highest (MIC = 0.06 mg/mL). The emulsion had a good DPPH (2,2-diphenyl-1-picrylhydrazine) radical scavenging activity that was dose-dependent and equal to 42.98% at the 0.08 mg/mL level with an IC value of 0.099 mg/mL. Based on the results, the caper leaf EO emulsion has the potential to be proposed as a natural alternative to chemical preservatives in the food industry.
PubMed: 38929157
DOI: 10.3390/antiox13060718 -
Biology May 2024Tomato bacterial spots, caused by pv. () and (), as well as bacterial specks, caused by two strains of pv. ( and ), represent significant threats to tomato...
Tomato bacterial spots, caused by pv. () and (), as well as bacterial specks, caused by two strains of pv. ( and ), represent significant threats to tomato production in the El-Sharkia governorate, often resulting in substantial yield losses. The objective of this study was to evaluate the efficacy of various biocontrol culture filtrates, including bacteria and fungi agents, in managing the occurrence and severity of these diseases, while also monitoring physiological changes in tomato leaves, including antioxidant enzymes, phenolics, and pigment content. The culture filtrates from examined species (, and ), as well as the tested bacteria (, , and ) at concentrations of 25%, 50%, and 100%, significantly inhibited the proliferation of pathogenic bacteria In vitro. For the In vivo experiments, we used specific doses of 5 mL of spore suspension per plant for the fungal bioagents at a concentration of 2.5 × 10 spores/mL. The bacterial bioagents were applied as a 10 mL suspension per plant at a concentration of 1 × 10 CFU/mL. Spraying the culture filtrates of the tested bioagents two days before infection In vivo significantly reduced disease incidence and severity. exhibited the highest efficacy among the fungal bioagents, followed by and . Meanwhile, the culture filtrate of emerged as the most potent among the bacterial bioagents, followed by . Furthermore, applying these culture filtrates resulted in elevated levels of chitinase, peroxidase, and polyphenol oxidase activity. This effect extended to increased phenol contents, as well as chlorophyll a, chlorophyll b, and carotenoids in sprayed tomato plants compared to the control treatment. Overall, these findings underscore the potential of these biocontrol strategies to effectively mitigate disease incidence and severity while enhancing plant defense mechanisms and physiological parameters, thus offering promising avenues for sustainable disease management in tomato production.
PubMed: 38927249
DOI: 10.3390/biology13060369 -
MSphere Jun 2024Microorganisms interact with plant roots through colonization of the root surface, i.e., the rhizoplane or the surrounding soil, i.e., the rhizosphere. Beneficial...
The potential of SBW25 to produce viscosin enhances wheat root colonization and shapes root-associated microbial communities in a plant genotype-dependent manner in soil systems.
UNLABELLED
Microorganisms interact with plant roots through colonization of the root surface, i.e., the rhizoplane or the surrounding soil, i.e., the rhizosphere. Beneficial rhizosphere bacteria such as spp. can promote plant growth and protect against pathogens by producing a range of bioactive compounds, including specialized metabolites like cyclic lipopeptides (CLPs) known for their biosurfactant and antimicrobial activities. However, the role of CLPs in natural soil systems during bacteria-plant interactions is underexplored. Here, SBW25, producing the CLP viscosin, was used to study the impact of viscosin on bacterial root colonization and microbiome assembly in two cultivars of winter wheat (Heerup and Sheriff). We inoculated germinated wheat seeds with SBW25 wild type or a viscosin-deficient mutant and grew the plants in agricultural soil. After 2 weeks, enhanced root colonization of SBW25 wild type compared to the viscosin-deficient mutant was observed, while no differences were observed between wheat cultivars. In contrast, the impact on root-associated microbial community structure was plant-genotype-specific, and SBW25 wild type specifically reduced the relative abundance of an unclassified oomycete and in Sheriff and Heerup, respectively. This study provides new insights into the natural role of viscosin and specifically highlights the importance of viscosin in wheat root colonization under natural soil conditions and in shaping the root microbial communities associated with different wheat cultivars. Furthermore, it pinpoints the significance of microbial microdiversity, plant genotype, and microbe-microbe interactions when studying colonization of plant roots.
IMPORTANCE
Understanding parameters governing microbiome assembly on plant roots is critical for successfully exploiting beneficial plant-microbe interactions for improved plant growth under low-input conditions. While it is well-known from studies that specialized metabolites are important for plant-microbe interactions, e.g., root colonization, studies on the ecological role under natural soil conditions are limited. This might explain the often-low translational power from laboratory testing to field performance of microbial inoculants. Here, we showed that viscosin synthesis potential results in a differential impact on the microbiome assembly dependent on wheat cultivar, unlinked to colonization potential. Overall, our study provides novel insights into factors governing microbial assembly on plant roots, and how this has a derived but differential effect on the bacterial and protist communities.
PubMed: 38904362
DOI: 10.1128/msphere.00294-24 -
Microbiology Resource Announcements Jun 2024We provide the complete genome sequence for a novel bacteriophage named UNO-G1W1. This phage was isolated from a single ice cover sampling. The genome was sequenced on...
We provide the complete genome sequence for a novel bacteriophage named UNO-G1W1. This phage was isolated from a single ice cover sampling. The genome was sequenced on the Nanopore MinION, generated with the direct terminal repeat-phage-pipeline and polished with Illumina short reads. Sequence identity classifies the phage as an .
PubMed: 38847506
DOI: 10.1128/mra.00384-24 -
Ecotoxicology and Environmental Safety Jul 2024This study aimed to evaluate the effect of adding liquid extract of algae (Hypnea musciformis, Grateloupia acuminata, and Sargassum muticum) (HGS) and Magnesium oxide...
Synergistic effect of green synthesis magnesium oxide nanoparticles and seaweed extract on improving water quality, health benefits, and disease resistance in Nile tilapia.
This study aimed to evaluate the effect of adding liquid extract of algae (Hypnea musciformis, Grateloupia acuminata, and Sargassum muticum) (HGS) and Magnesium oxide nanoparticles (MgO NPs) using this extract to rear water of Oreochromis niloticus, on improving culture water indices, growth performance, digestive enzyme, hemato-biochemical characters, immune, antioxidative responses, and resistance after challenged by Aeromonas hydrophila with specific refer to the potential role of the mixture in vitro as resistance against three strains bacteria (Aeromonas sobria, Pseudomonas fluorescens, P. aeruginosa) and one parasite (Cichlidogyrus tilapia). The first group represented control, HGS0, whereas the other group, HGS5, HGS10, and HGS15 mL of liquid extract, as well as all groups with 7.5 μg mL MgO-NPs added to culture water of O. niloticus, for 60 days. Data showed that increasing levels at HGS 10 and HGS15 mL in to-culture water significantly enhanced growth-stimulating digestive enzyme activity and a significantly improved survival rate of O. niloticus after being challenged with A. hydrophila than in the control group. The total viability, coliform, fecal coliform count, and heavy metal in muscle partially decreased at HGS 10 and HGS15 mL than in the control group. Correspondingly, the highest positive effect on hemato-biochemical indices was noticed at levels HGS 10 and HGS15 mL. Fish noticed an improvement in immune and antioxidant indices compared to control groups partially at HGS 10 and HGS15 mL. Interestingly, fish cultured in rearing water with the mixture provided downregulated the related inflammatory genes (HSP70, TNF, IL-1β, and IL-8) partially at HGS15 mL. In vitro, the mixture showed positive efficiency as an antibacterial and partially antiparasitic at HGS 10 and HGS15 mL. This study proposes utilizing a mixture of (HGS) and (MgO-NPs) with optimum levels of 10-15 mL in cultured water to improve water indices, growth, health status, and increased resistance of O. niloticus against bacterial and parasitic infection.
Topics: Animals; Magnesium Oxide; Cichlids; Disease Resistance; Water Quality; Seaweed; Fish Diseases; Plant Extracts; Nanoparticles; Green Chemistry Technology; Metal Nanoparticles; Aeromonas hydrophila; Sargassum
PubMed: 38843743
DOI: 10.1016/j.ecoenv.2024.116522 -
BioRxiv : the Preprint Server For... May 2024are exposed to a variety of pathogenic and non-pathogenic bacteria species in their natural environment. Correspondingly, has evolved an ability to discern between...
are exposed to a variety of pathogenic and non-pathogenic bacteria species in their natural environment. Correspondingly, has evolved an ability to discern between nutritive and infectious bacterial food sources. Here we show that can learn to avoid the pathogenic bacteria (PF15), and that this learned avoidance behavior is passed on to progeny for four generations, as we previously demonstrated for (PA14) and , using similar mechanisms, including the involvement of both the TGF-β ligand DAF-7 and retrotransposon-encoded virus-like particles. PF15 small RNAs are both necessary and sufficient to induce this transgenerational avoidance behavior. Unlike PA14 or , PF15 does not use P11, Pv1, or a small RNA with homology for this avoidance; instead, an unrelated PF15 small RNA, Pfs1, that targets the Ephrin receptor gene is necessary and sufficient for learned avoidance, suggesting the evolution of yet another bacterial sRNA/ gene target pair involved in transgenerational inheritance of pathogen avoidance. As VAB-2 Ephrin receptor ligand and MACO-1 knockdown also induce PF15 avoidance, we have begun to understand the genetic pathway involved in small RNA targeted pathogenic avoidance. Moreover, these data show that axon guidance pathway genes (VAB-1 and VAB-2) have previously unknown adult roles in regulating neuronal function. may have evolved multiple bacterial specificity-encoded small RNA-dependent mechanisms to avoid different pathogenic bacteria species, thereby providing progeny with a survival advantage in a dynamic environment.
PubMed: 38826453
DOI: 10.1101/2024.05.23.595334 -
Microbial Cell Factories Jun 2024Syringic acid (SA) is a high-value natural compound with diverse biological activities and wide applications, commonly found in fruits, vegetables, and herbs. SA is...
BACKGROUND
Syringic acid (SA) is a high-value natural compound with diverse biological activities and wide applications, commonly found in fruits, vegetables, and herbs. SA is primarily produced through chemical synthesis, nonetheless, these chemical methods have many drawbacks, such as considerable equipment requirements, harsh reaction conditions, expensive catalysts, and numerous by-products. Therefore, in this study, a novel biotransformation route for SA production was designed and developed by using engineered whole cells.
RESULTS
An O-methyltransferase from Desulfuromonas acetoxidans (DesAOMT), which preferentially catalyzes a methyl transfer reaction on the meta-hydroxyl group of catechol analogues, was identified. The whole cells expressing DesAOMT can transform gallic acid (GA) into SA when S-adenosyl methionine (SAM) is used as a methyl donor. We constructed a multi-enzyme cascade reaction in Escherichia coli, containing an endogenous shikimate kinase (AroL) and a chorismate lyase (UbiC), along with a p-hydroxybenzoate hydroxylase mutant (PobA) from Pseudomonas fluorescens, and DesAOMT; SA was biosynthesized from shikimic acid (SHA) by using whole cells catalysis. The metabolic system of chassis cells also affected the efficiency of SA biosynthesis, blocking the chorismate metabolism pathway improved SA production. When the supply of the cofactor NADPH was optimized, the titer of SA reached 133 μM (26.2 mg/L).
CONCLUSION
Overall, we designed a multi-enzyme cascade in E. coli for SA biosynthesis by using resting or growing whole cells. This work identified an O-methyltransferase (DesAOMT), which can catalyze the methylation of GA to produce SA. The multi-enzyme cascade containing four enzymes expressed in an engineered E. coli for synthesizing of SA from SHA. The metabolic system of the strain and biotransformation conditions influenced catalytic efficiency. This study provides a new green route for SA biosynthesis.
Topics: Gallic Acid; Biocatalysis; Escherichia coli; Metabolic Engineering; Methyltransferases; Shikimic Acid; Pseudomonas fluorescens; Biotransformation
PubMed: 38824548
DOI: 10.1186/s12934-024-02441-x -
Pharmaceutics May 2024In recent decades, ionic liquids (ILs) have garnered research interest for their noteworthy properties, such as thermal stability, low or no flammability, and negligible...
In recent decades, ionic liquids (ILs) have garnered research interest for their noteworthy properties, such as thermal stability, low or no flammability, and negligible vapour pressure. Moreover, their tunability offers limitless opportunities to design ILs with properties suitable for applications in many industrial fields. This study aims to synthetise two series of methylimidazolium ILs bearing long alkyl chain in their cations (C9, C10, C12, C14, C16, C18, C20) and with tetrafluoroborate (BF) and the 1,3-dimethyl-5-sulfoisophthalate (DMSIP) as counter ions. The ILs were characterised using H-NMR and MALDI-TOF, and their thermal behaviour was investigated through DSC and TGA. Additionally, the antimicrobial, anticancer, and cytotoxic activities of the ILs were analysed. Moreover, the most promising ILs were incorporated at different concentrations (0.5, 1, 5 wt%) into polyvinyl chloride (PVC) by solvent casting to obtain antimicrobial blend films. The thermal properties and stability of the resulting PVC/IL films, along with their hydrophobicity/hydrophilicity, IL surface distribution, and release, were studied using DSC and TGA, contact angle (CA), SEM, and UV-vis spectrometry, respectively. Furthermore, the antimicrobial and cytotoxic properties of blends were analysed. The in vitro results demonstrated that the antimicrobial and antitumor activities of pure ILs against t , , strains, and the breast cancer cell line (MCF7), respectively, were mainly dependent on their structure. These activities were higher in the series containing the BF anion and increased with the increase in the methylimidazolium cation alkyl chain length. However, the elongation of the alkyl chain beyond C16 induced a decrease in antimicrobial activity, indicating a cut-off effect. A similar trend was also observed in terms of in vitro biocompatibility. The loading of both the series of ILs into the PVC matrix did not affect the thermal stability of PVC blend films. However, their T decreased with increased IL concentration and alkyl chain length. Similarly, both the series of PVC/IL films became more hydrophilic with increasing IL concentration and alkyl chain. The loading of ILs at 5% concentration led to considerable IL accumulation on the blend film surfaces (as observed in SEM images) and, subsequently, their higher release. The biocompatibility assessment with healthy human dermal fibroblast (HDF) cells and the investigation of antitumoral properties unveiled promising pharmacological characteristics. These findings provide strong support for the potential utilisation of ILs in biomedical applications, especially in the context of cancer therapy and as antibacterial agents to address the challenge of antibiotic resistance. Furthermore, the unique properties of the PVC/IL films make them versatile materials for advancing healthcare technologies, from drug delivery to tissue engineering and antimicrobial coatings to diagnostic devices.
PubMed: 38794304
DOI: 10.3390/pharmaceutics16050642 -
Microorganisms May 2024Lactoperoxidase (LP) is an important enzyme of the salivary and mammary glands. It has been proven to increase the shelf life of raw milk by inhibiting the growth of...
Lactoperoxidase (LP) is an important enzyme of the salivary and mammary glands. It has been proven to increase the shelf life of raw milk by inhibiting the growth of bacteria, especially , , , and spp. The aim of this work was to verify the use of LP to extend the shelf life of meat products. In vitro experiments showed inhibitory effects on the selected bacteria ( (ATCC 33090), (CP054440.1), and (ATCC 13525) due to a prolongation of the lag phase of growth curves. A lower increase in viable counts ( < 0.05) was also found by testing pork cubes' surface treated with LP solution (5%) + and stored for 7 days at 15 °C. LP has also been studied at concentrations of 0.25 and 0.50% in meat products (pork ham and pâté) during refrigerated storage (4 °C for 28 days). Lower viable counts were observed throughout the storage experiment, especially for 0.50% LP ( < 0.05). Meat products containing LP also showed lower levels of oxidation (MAD) ( < 0.05). According to these results, LP could extend the shelf life of a wider range of products.
PubMed: 38792839
DOI: 10.3390/microorganisms12051010