Effects of glycosylation on swimming ability and flagellar polymorphic transformation in Pseudomonas syringae pv. tabaci 6605

The role of flagellin glycosylation on motility was investigated in Pseudomonas syringae pv. tabaci. The swimming activity of glycosylation-defective mutants was prominently decreased in a highly viscous medium. The mutants showed differences in polymorphic transitions and in the bundle formation of flagella, indicating that glycosylation stabilizes the filament structure and lubricates the rotation of the bundle.</p

Indigo-Mediated Semi-Microbial Biofuel Cell Using an Indigo-Dye Fermenting Suspension

Aizome (Japanese indigo dyeing) is a unique dyeing method using microbial activity under anaerobic alkaline conditions. In indigo-dye fermenting suspensions; microorganisms reduce indigo into leuco-indigo with acetaldehyde as a reductant. In this study; we constructed a semi-microbial biofuel cell using an indigo-dye fermenting suspension. Carbon fiber and Pt mesh were used as the anode and cathode materials, respectively. The open-circuit voltage (OCV) was 0.6 V, and the maximum output power was 32 µW cm−2 (320 mW m−2). In addition, the continuous stability was evaluated under given conditions starting with the highest power density; the power density rapidly decreased in 0.5 h due to the degradation of the anode. Conversely, at the OCV, the anode potential exhibited high stability for two days. However, the OCV decreased by approximately 80 mV after 2 d compared with the initial value, which was attributed to the performance degradation of the gas-diffusion-cathode system caused by the evaporation of the dispersion solution. This is the first study to construct a semi-microbial biofuel cell using an indigo-dye fermenting suspension

Mechanistic Insights into Indigo Reduction in Indigo Fermentation : A Voltammetric Study

Indigo is one of the oldest natural blue dyes. Microorganisms and their enzymatic activities are deeply involved in the traditional indigo staining procedure. To elucidate the mechanism of the microbial indigo reduction, we directly performed cyclic voltammetry on alkaline fermenting dye suspensions. A pair of characteristic redox peaks of leuco-indigo was observed in a supernatant fluid of the fermenting dye suspension. On the other hand, it was found that the indigo/leuco-indigo redox couple mediated two-way microbially catalyzed oxidation and reduction in a sediment-rich suspension of the fermenting suspension. Acetaldehyde was supposed to be the electron donor and acceptor of the catalytic reactions. In order to verify the bioelectrocatalytic reaction, we isolated indigo-reducing bacterium K2-3′ from the fermenting suspension, and the two-way bioelectrocatalysis was successfully restaged in a model system containing K2-3′ and methyl viologen (as a soluble mediator instead of indigo) as well as acetaldehyde at pH 10

Identification of glycosylation genes and glycosylated amino acids of flagellin in Pseudomonas syringae pv. tabaci

A glycosylation island is a genetic region required for glycosylation. The glycosylation island of flagellin in Pseudomonas syringae pv. tabaci 6605 consists of three orfs: orf1, orf2 and orf3. Orf1 and orf2 encode putative glycosyltransferases, and their deletion mutants, Delta orf1 and Delta orf2, exhibit deficient flagellin glycosylation or produce partially glycosylated flagellin respectively. Digestion of glycosylated flagellin from wild-type bacteria and non-glycosylated flagellin from Delta orf1 mutant using aspartic N-peptidase and subsequent HPLC analysis revealed candidate glycosylated amino acids. By generation of site-directed Ser/Ala-substituted mutants, all glycosylated amino acid residues were identified at positions 143, 164, 176, 183, 193 and 201. Matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (MS) analysis revealed that each glycan was about 540 Da. While all glycosylation-defective mutants retained swimming ability, swarming ability was reduced in the Delta orf1, Delta orf2 and Ser/Ala-substituted mutants. All glycosylation mutants were also found to be impaired in the ability to adhere to a polystyrene surface and in the ability to cause disease in tobacco. Based on the predicted tertiary structure of flagellin, S176 and S183 are expected to be located on most external surface of the flagellum. Thus the effect of Ala-substitution of these serines is stronger than that of other serines. These results suggest that glycosylation of flagellin in P. syringae pv. tabaci 6605 is required for bacterial virulence. It is also possible that glycosylation of flagellin may mask elicitor function of flagellin molecule

ABO Blood Incompatibility Positively Affects Early Graft Function: Single-Center Retrospective Cohort Study

Background We investigated the association between ABO-incompatible (ABO-I) kidney transplantation and early graft function. Methods We retrospectively analyzed 95 patients who underwent living donor kidney transplantation between May 2009 and July 2019. It included 61 ABO-compatible (ABO-C) and 34 ABO-I transplantations. We extracted data on immunologic profile, sex, age, cold ischemic time, type of immunosuppression, and graft function. Two definitions were used for slow graft function (SGF) as follows: postoperative day (POD) 3 serum creatinine level >3 mg/dL and estimated glomerular filtration rate (eGFR) Results The characteristics between the ABO-C and ABO-I were not different. ABO-I received rituximab and plasma exchange. Patients also received tacrolimus and mycophenolate mofetil for 2 weeks and prednisolone for 1 week before transplantation as preconditioning. Of the 95 study patients, 19 (20%) and 21 (22%) were identified with SGF according to POD 3 serum creatinine level or eGFR, respectively. Multivariable analysis revealed that ABO-I significantly reduced the incidence of SGF (odds ratio, 0.15; 95% confidence interval, 0.03-0.7; P = .02), and cold ischemic time >150 min increased the incidence of SGF (odds ratio, 6.5; 95% confidence interval, 1.7-25; P = .006). Similar results were identified in POD 3 eGFR. Inferior graft function in patients with SGF was identified up to 6 months after transplantation. Conclusion ABO-I reduces the incidence of SGF, which is associated with an inferior graft function up to 6 months

Feasible kidney donation with living marginal donors, including diabetes mellitus

Objectives: To compare the donor outcomes of living donor kidney transplantation between standard donors (SDs) and marginal donors (MDs) including diabetic patients (MD + DM). Methods: MDs were defined according to Japanese guideline criteria: (a) age >70-years, (b) blood pressure 25 to = 70 to 6.2 or Results: No kidney function parameters were different between SDs and MDs. When comparing SD and MD + DM, MD + DM had a lower postoperative eGFR (48 vs. 41 (1 (month), p = .02), 49 vs. 40 (12, p = 2 risk factors. Conclusions: Although long-term observation of donor kidney function is necessary, careful MD + DM selection had the potential to expand the donor pool

On the origin and evolution of the asteroid Ryugu: A comprehensive geochemical perspective

Presented here are the observations and interpretations from a comprehensive analysis of 16 representative particles returned from the C-type asteroid Ryugu by the Hayabusa2 mission. On average Ryugu particles consist of 50% phyllosilicate matrix, 41% porosity and 9% minor phases, including organic matter. The abundances of 70 elements from the particles are in close agreement with those of CI chondrites. Bulk Ryugu particles show higher δ18O, Δ17O, and ε54Cr values than CI chondrites. As such, Ryugu sampled the most primitive and least-thermally processed protosolar nebula reservoirs. Such a finding is consistent with multi-scale H-C-N isotopic compositions that are compatible with an origin for Ryugu organic matter within both the protosolar nebula and the interstellar medium. The analytical data obtained here, suggests that complex soluble organic matter formed during aqueous alteration on the Ryugu progenitor planetesimal (several 10’s of km), <2.6 Myr after CAI formation. Subsequently, the Ryugu progenitor planetesimal was fragmented and evolved into the current asteroid Ryugu through sublimation

A pristine record of outer Solar System materials from asteroid Ryugu’s returned sample

Volatile and organic-rich C-type asteroids may have been one of the main sources of Earth’s water. Our best insight into their chemistry is currently provided by carbonaceous chondritic meteorites, but the meteorite record is biased: only the strongest types survive atmospheric entry and are then modified by interaction with the terrestrial environment. Here we present the results of a detailed bulk and microanalytical study of pristine Ryugu particles, brought to Earth by the Hayabusa2 spacecraft. Ryugu particles display a close compositional match with the chemically unfractionated, but aqueously altered, CI (Ivuna-type) chondrites, which are widely used as a proxy for the bulk Solar System composition. The sample shows an intricate spatial relationship between aliphatic-rich organics and phyllosilicates and indicates maximum temperatures of ~30 °C during aqueous alteration. We find that heavy hydrogen and nitrogen abundances are consistent with an outer Solar System origin. Ryugu particles are the most uncontaminated and unfractionated extraterrestrial materials studied so far, and provide the best available match to the bulk Solar System composition

Influx of nitrogen-rich material from the outer Solar System indicated by iron nitride in Ryugu samples

Large amounts of nitrogen compounds, such as ammonium salts, may be stored in icy bodies and comets, but the transport of these nitrogen-bearing solids into the near-Earth region is not well understood. Here, we report the discovery of iron nitride on magnetite grains from the surface of the near-Earth C-type carbonaceous asteroid Ryugu, suggesting inorganic nitrogen fixation. Micrometeoroid impacts and solar wind irradiation may have caused the selective loss of volatile species from major iron-bearing minerals to form the metallic iron. Iron nitride is a product of nitridation of the iron metal by impacts of micrometeoroids that have higher nitrogen contents than the CI chondrites. The impactors are probably primitive materials with origins in the nitrogen-rich reservoirs in the outer Solar System. Our observation implies that the amount of nitrogen available for planetary formation and prebiotic reactions in the inner Solar System is greater than previously recognized