Construction and characterization of a hypervesiculation strain of Escherichia coli Nissle 1917.

Outer membrane vesicles (OMVs) are produced by Gram-negative bacteria and deliver microbial molecules to distant target cells in a host. OMVs secreted by probiotic probiotic strain Escherichia coli Nissle 1917 (EcN) have been reported to induce an immune response. In this study, we aimed to increase the OMV production of EcN.

Identification of emulsification proteins released from the cells by inhibiting the synthesis of GPI-anchor or β-1,3-glucan in Candida albicans.

Introduction: A previous study demonstrated a strong emulsification ability of the culture supernatant obtained by cultivation of Candida albicans in a medium containing a β-1,3-glucan synthesis inhibitor and proposed a novel screening method using emulsification as an indicator for β-1,3-glucan synthesis inhibition (Nerome et al., 2021. Evaluating β-1,3-glucan synthesis inhibition using emulsion formation as an indicator.

Quantitative analysis of phosphate accumulation in PHO regulatory system-mutant strains of Saccharomyces cerevisiae.

PHO-mutant strains of Saccharomyces cerevisiae, NOF-1 and NBD82-1, which constitutively express PHO81 and PHO4, respectively, have been reported to accumulate phosphate in high-phosphate conditions. However, detailed analysis, including a quantitative evaluation of the accumulated phosphate, has not been performed for these mutants. In this study, NOF-1 and NBD82-1 mutant and double mutant strains were cultured in a high-phosphate medium to quantitatively analyze the amount, accumulation form, and physiological use of the accumulated phosphate in the cells.

Concentrative Nucleoside Transporter, CNT, Results in Selective Toxicity of Toyocamycin against Candida albicans.

Toyocamycin (TM) is an adenosine-analog antibiotic isolated from Streptomyces toyocaensis. It inhibits Candida albicans, several plant fungal pathogens, and human cells, but many fungi, including Saccharomyces cerevisiae, are much less susceptible to TM. Aiming to clarify why TM and its analogs tubercidin and 5-iodotubercidin are active against C.

Evaluating β-1,3-glucan synthesis inhibition using emulsion formation as an indicator.

Introduction: The cell wall β-1,3-glucan of fungal pathogen Candida albicans is an attractive antifungal target. β-1,3-Glucan is the skeletal structure in the cell wall and the major scaffold for cell wall proteins. In previous studies using Saccharomyces cerevisiae, strong emulsification was detected by mixing cell wall proteins with oil.

Mineralization induced by phosphorylated dry baker's yeast.

We found the mineralization of Cu during long-term Cu2+ adsorption onto dry baker's yeast cells phosphorylated using sodium cyclo-triphosphate. Field emission scanning electron microscopy (FESEM) with energy-dispersive X-ray spectroscopy confirmed that the elemental composition of minerals were copper, phosphorus, and oxygen. Synchrotron-based X-ray absorption fine structure showed that the local structure around Cu atoms deposited on the mineral was almost identical to that of commercial copper (II) phosphate Cu3(PO4)2∙3H2O.

Enhanced floc formation by degP-deficient Escherichia coli cells in the presence of glycerol.

Flocculation is an aggregation phenomenon of microbial cells in which they form flocs or flakes. In this study, it was found that addition of glycerol to a complex glucose medium promoted spontaneous floc formation by an Escherichia coli degP-deficient mutant strain (ΔdegP) in a dose-dependent manner. In the presence of 10% (v/v) glycerol, the amount of floc formation (quantified as floc protein) reached its maximum value (230 mg/L), five times that in its absence.

Cell surface changes that advance the application of using yeast as a food emulsifier.

A previous study revealed that Saccharomyces cerevisiae mcd4Δ, a cell wall mutant with a defect in the synthesis of the glycosylphosphatidylinositol anchor, has a strong macrophage activation ability. In this study, remarkable emulsion formation after cell suspensions of mcd4Δ and anp1Δ (which exhibit an extreme reduction of mannan) were mixed with oil was found. Moreover, the relationship between cell wall mutation and emulsion formation was investigated, suggesting that och1Δ with a defect in the formation of N-linked glycans also had a strong emulsification ability and that high molecular weight materials released from the cells were involved in emulsion formation.

Construction of hypervesiculation Escherichia coli strains and application for secretory protein production.

Outer membrane vesicles (OMVs) are extracellular vesicles released from the surface of Gram-negative bacteria, including Escherichia coli. Several gene-deficient mutants relating to envelope stress (nlpI and degP) and phospholipid accumulation in the outer leaflet of the outer membrane (mlaA and mlaE) increase OMV production. This study examined the combinatorial deletion of these genes in E.

Promoted performance of microbial fuel cells using Escherichia coli cells with multiple-knockout of central metabolism genes.

The effect of central metabolic activity of Escherichia coli cells acting as biocatalysts on the performance of microbial fuel cells (MFCs) was studied with glucose used as the energy source. Milliliter-scale two-chambered MFCs were used with 2-hydroxy-1,4-naphthoquinone (HNQ) as an electron mediator. Among the single-gene deletions examined, frdA, pdhR, ldhA, and adhE increased the average power output of the constructed MFC.

Knockout of pgdS and ggt gene changes poly-γ-glutamic acid production in Bacillus licheniformis RK14-46.

Poly-gamma-glutamic acid (γ-PGA) is a water-soluble, nontoxic biocompatible polymer, which is extensively used in medicines, foodstuffs, cosmetics, and in water treatment. We previously isolated a novel γ-PGA producing strain Bacillus licheniformis RK14 from soil and developed a hyper-producing mutant strain RK14-46 by an ethyl methanesulfonate (EMS) treatment. In this study, endo-type (pgdS) and exo-type γ-PGA hydrolases (ggt) were disrupted by integrating plasmids into the genomic DNA of B.

Recovering metals from aqueous solutions by biosorption onto phosphorylated dry baker's yeast.

Biosorption is a cost-effective and simple technique for removing heavy metals and rare earth elements from aqueous solution. Here, metals were recovered from aqueous solutions using phosphorylated dry baker's yeast cells. The cells were phosphorylated using cyclo-triphosphate, NaPO.

Inducing flocculation of non-floc-forming Escherichia coli cells.

The present article reviews several approaches for inducing flocculation of Escherichia coli cells. The common industrially used bacterium E. coli does not naturally have floc-forming ability.

Large-scale culture of a megakaryocytic progenitor cell line with a single-use bioreactor system.

The increasing application of regenerative medicine has generated a growing demand for stem cells and their derivatives. Single-use bioreactors offer an attractive platform for stem cell expansion owing to their scalability for large-scale production and feasibility of meeting clinical-grade standards. The current work evaluated the capacity of a single-use bioreactor system (1 L working volume) for expanding Meg01 cells, a megakaryocytic (MK) progenitor cell line.

Displaying a recombinant protein on flocs self-produced by Escherichia coli through fused expression with elongation factor Ts.

The utility of engineering flocculation is wildly recognized in applied and environmental microbiology. We previously reported self-produced flocculation of Escherichia coli cells by overexpressing the native bcsB gene that encodes a component of the cellulose synthesis pathway. Further experiments clarified that the spontaneous E.

Quantitative Evaluation of Recombinant Protein Packaged into Outer Membrane Vesicles of Escherichia coli Cells.

Outer membrane vesicles (OMVs) are spherical bilayered proteolipids released from the cell surfaces of bacteria, which have gained traction in the biotechnology fields. Bacterial cellular machinery can be genetically engineered to produce and package heterologous enzymes into OMVs, producing nanocarriers and nanoparticle catalysts. However, the productivity or efficiency of packaging the target protein into OMVs has not been quantitatively evaluated.

Over-expression, characterization, and modification of highly active alkaline phosphatase from a Shewanella genus bacterium.

We isolated a Shewanella sp. T3-3 bacterium that yielded highly active alkaline phosphatase (APase). We then cloned the APase gene from Shewanella sp.

Deletion of degQ gene enhances outer membrane vesicle production of Shewanella oneidensis cells.

Shewanella oneidensis is a Gram-negative facultative anaerobe that can use a wide variety of terminal electron acceptors for anaerobic respiration. In this study, S. oneidensis degQ gene, encoding a putative periplasmic serine protease, was cloned and expressed.

Antibiofilm effect of warfarin on biofilm formation of Escherichia coli promoted by antimicrobial treatment.

Enhancement of microbial biofilm formation by low antimicrobial doses is a critical problem in the medical field. The objective of this study was to propose a new drug candidate against the biofilm formation promoted by subinhibitory dose of antimicrobials. To determine the effect on biofilm formation of Escherichia coli, a subinhibitory concentration of lactoferrin (LF), a milk protein involved in a broad range of biological properties including antimicrobial action, or ampicillin (AMP), a typical antibiotic, was added to an E.

Recent developments in ex vivo platelet production.

The platelet is a component of blood that functions to initiate blood clotting. Abnormal platelet count and function can lead to a life-threatening condition caused by excessive bleeding. At present, platelet supply for transfusion can be obtained only from platelet donation.

Flocculation of Escherichia coli Cells in Association with Enhanced Production of Outer Membrane Vesicles.

Microbial flocculation is a phenomenon of aggregation of dispersed bacterial cells in the form of flocs or flakes. In this study, the mechanism of spontaneous flocculation of Escherichia coli cells by overexpression of the bcsB gene was investigated. The flocculation induced by overexpression of bcsB was consistent among the various E.

Exopolysaccharide assay in Escherichia coli microcolonies using a cleavable fusion protein of GFP-labeled carbohydrate-binding module.

A fused protein composed of a carbohydrate-binding module and green fluorescence protein (GFP) was developed to measure the exopolysaccharides (EPShs) present in Escherichia coli microcolonies. The cleavage of the GFP part of this protein using a site-specific protease allowed for the non-invasive and quantitative evaluation of the EPShs.

Promoted megakaryocytic differentiation of K562 cells through oxidative stress caused by near ultraviolet irradiation.

Reactive oxygen species (ROS) have been proven to be important activators for various cellular activities, including cell differentiation. Several reports showed the necessity of ROS during cell differentiation of the megakaryocytic (MK) lineage. In this study, we employed near ultraviolet (near-UV) irradiation to generate endogenous oxidative stress in an MK differentiation process of K562 cells with phorbol 12-myristate 13-acetate (PMA) induction.