Potentiality of Beneficial Microbe Bacillus siamensis GP-P8 for the Suppression of Anthracnose Pathogens and Pepper Plant Growth Promotion.

This study was carried out to screen the antifungal activity against Colletotrichum acutatum, Colletotrichum dematium, and Colletotrichum coccodes. Bacterial isolate GP-P8 from pepper soil was found to be effective against the tested pathogens with an average inhibition rate of 70.7% in in vitro dual culture assays. 16S rRNA gene sequencing analysis result showed that the effective bacterial isolate as Bacillus siamensis. Biochemical characterization of GP-P8 was also performed. According to the results, protease and cellulose, siderophore production, phosphate solubilization, starch hydrolysis, and indole-3-acetic acid production were shown by the GP-P8. Using specific primers, genes involved in the production of antibiotics, such as iturin, fengycin, difficidin, bacilysin, bacillibactin, surfactin, macrolactin, and bacillaene were also detected in B. siamensis GP-P8. Identification and analysis of volatile organic compounds through solid phase microextraction/gas chromatography-mass spectrometry (SPME/GC-MS) revealed that acetoin and 2,3-butanediol were produced by isolate GP-P8. In vivo tests showed that GP-P8 significantly reduced the anthracnose disease caused by C. acutatum, and enhanced the growth of pepper plant. Reverse transcription polymerase chain reaction analysis of pepper fruits revealed that GP-P8 treated pepper plants showed increased expression of immune genes such as CaPR1, CaPR4, CaNPR1, CaMAPK4, CaJA2, and CaERF53. These results strongly suggest that GP-P8 could be a promising biocontrol agent against pepper anthracnose disease and possibly a pepper plant growth-promoting agent.

Structure modeling-based characterization of ChnD, the 6-hydroxyhexanoate dehydrogenase from Acinetobacter sp. strain NCIMB 9871.

α,ω-Dicarboxylic acids, ω-aminoalkanoic acids, and α,ω-diaminoalkanes are valuable building blocks for the production of biopolyesters and biopolyamides. One of the key steps in producing these chemicals is the oxidation of ω-hydroxycarboxylic acids using alcohol dehydrogenases (e.g., ChnD of Acinetobacter sp. NCIMB 9871). However, the reaction and structural features of these enzymes remain mostly undiscovered. Thereby, we have investigated characteristics of ChnD based on enzyme kinetics, substrate-docking simulations, and mutation studies. Kinetic analysis revealed a distinct preference of ChnD for medium chain ω-hydroxycarboxylic acids, with the highest catalytic efficiency of 18.0 mM-1s-1 for 12-hydroxydodecanoic acid among C6 to C12 ω-hydroxycarboxylic acids. The high catalytic efficiency was attributed to the positive interactions between the carboxyl group of the substrates and the guanidino group of two arginine residues (i.e., Arg62 and Arg266) in the substrate binding site. The ChnD_R62L variant showed the increased efficiency and affinity, particularly for fatty alcohols (i.e., C6-C10) and branched-chain fatty alcohols, such as 3-methyl-2-buten-1-ol. Overall, this study contributes to the deeper understanding of medium-chain primary aliphatic alcohol dehydrogenases and their applications for the production of industrially relevant chemicals such as α,ω-dicarboxylic acids, ω-aminoalkanoic acids, and α,ω-diaminoalkanes from renewable biomass.

Attentional bias for high-calorie food cues by the level of hunger and satiety in individuals with binge eating behaviors.

Introduction: The abnormal hyperreactivity to food cues in individuals with binge eating behaviors could be regulated by hedonic or reward-based system, overriding the homeostatic system. The aim of the present study was to investigate whether attentional bias for food cues is affected by the level of hunger, maintaining the normal homeostatic system in individuals with binge eating behaviors. Methods: A total of 116 female participants were recruited and divided into four groups: hungry-binge eating group (BE) (n = 29), satiated BE (n = 29), hungry-control (n = 29), satiated control (n = 29). While participants completed a free-viewing task on high or low-calorie food cues, visual attentional processes were recorded using an eye tracker. Results: The results revealed that BE group showed longer initial fixation duration toward high-calorie food cues in both hunger and satiety condition in the early stage, whereas the control group showed longer initial fixation duration toward high-calorie food cues only in hunger conditions. Moreover, in the late stage, the BE group stared more at the high-calorie food cue, compared to control group regardless of hunger and satiety. Discussion: The findings suggest that automatic attentional bias for food cues in individuals with binge eating behaviors occurred without purpose or awareness is not affected by the homeostatic system, while strategic attention is focused on high-calorie food. Therefore, the attentional processing of food cues in binge eating group is regulated by hedonic system rather than homeostatic system, leading to vulnerability to binge eating.

A uniform conditioning regimen of busulfan, fludarabine, and antithymocyte globulin for allogeneic haematopoietic cell transplantation from haploidentical family, matched sibling, or unrelated donors-A single-centre, prospective, explorative study.

In a prospective, explorative study, the donor-source difference of haploidentical family (HF), matched sibling (MS), and unrelated donors (UD) was evaluated for the outcome of haematopoietic cell transplantations (HCT) in 101 patients with acute myeloid leukaemia (AML) in complete remission (CR). To eliminate compounding effects, a uniform conditioning regimen containing antithymocyte globulin (ATG) was used. After transplantation, there was a significantly higher cumulative incidence of acute graft-versus-host disease (GVHD) in HF-HCT patients (49%, 7%, and 16% for HF-, MS- and UD-HCT respectively; p < 0.001). A quarter of acute GVHD cases observed in HF-HCT patients occurred within three days of engraftment and were characterized by diffuse skin rash, fever, weight gain, and hypoalbuminaemia. This peri-engraftment acute GVHD was not observed in MS-HCT or UD-HCT patients. Additionally, a significantly higher proportion of HF-HCT patients achieved complete donor chimaerism in the peripheral mononuclear cells at one month (88%, 46%, and 69% for HF-, MS- and UD-HCT respectively; p = 0.001). There was no significant difference in engraftment, chronic GVHD, leukaemia recurrence, non-relapse mortality, and patient survival. In patients with AML in CR who received HCT using ATG-containing conditioning, stronger donor-patient alloreactivity was observed in HF-HCT, in terms of increased acute GVHD and higher likelihood of complete donor chimaerism.

Engineering of a bacterial outer membrane vesicle to a nano-scale reactor for the biodegradation of ß-lactam antibiotics.

Bacterial outer membrane vesicles (OMVs) are small unilamellar proteoliposomes, which are involved in various functions including cell to cell signaling and protein excretion. Here, we have engineered the OMVs of Escherichia coli to nano-scaled bioreactors for the degradation of ß-lactam antibiotics. This was exploited by targeting a ß-lactamase (i.e., CMY-10) into the OMVs of a hyper-vesiculating E. coli BL21(DE3) mutant. The CMY-10-containing OMVs, prepared from the E. coli mutant cultures, were able to hydrolyze ß-lactam ring of nitrocefin and meropenem to a specific rate of 6.6 × 10-8 and 3.9 × 10-12 µmol/min/µm3 of OMV, which is approximately 100 and 600-fold greater than those of E. coli-based whole-cell biocatalsyts. Furthermore, CMY-10, which was encapsulated in the engineered OMVs, was much more stable against temperature and acid stresses, as compared to free enzymes in aqueous phase. The OMV-based nano-scaled reaction system would be useful for the remediation of a variety of antibiotics pollution for food and agricultural industry.

Incidence, Management, and Prognosis of Graft Failure and Autologous Reconstitution after Allogeneic Hematopoietic Stem Cell Transplantation.

BACKGROUND: This study presents outcomes of management in graft failure (GF) after allogeneic hematopoietic stem cell transplantation (HCT) and provides prognostic information including rare cases of autologous reconstitution (AR). METHODS: We analyzed risk factors and outcomes of primary and secondary GF, and occurrence of AR in 1,630 HCT recipients transplanted over period of 18 years (January 2000-September 2017) at our center. RESULTS: Primary and secondary GF occurred in 13 (0.80%), and 69 patients (10-year cumulative incidence, 4.5%) respectively. No peri-transplant variables predicted primary GF, whereas reduced intensity conditioning (RIC) regimen (relative risk [RR], 0.97-28.0, P < 0.001) and lower CD34⁺ cell dose (RR, 2.44-2.84, P = 0.002) were associated with higher risk of secondary GF in multivariate analysis. Primary GF demonstrated 100% mortality, in the secondary GF group, the 5-year Kaplan-Meier survival rate was 28.8%, relapse ensued in 18.8%, and AR was observed in 11.6% (n = 8). In survival analysis, diagnosis of aplastic anemia (AA), chronic myeloid leukemia and use of RIC had a positive impact. There were 8 patients who experienced AR, which was rarely reported after transplantation for acute leukemia. Patient shared common characteristics such as young age (median 25 years), use of RIC regimen, absence of profound neutropenia, and had advantageous survival rate of 100% during follow period without relapse. CONCLUSION: Primary GF exhibited high mortality rate. Secondary GF had 4.5% 10-year cumulative incidence, median onset of 3 months after HCT, and showed 5-year Kaplan-Meier survival of 28.8%. Diagnosis of severe AA and use of RIC was both associated with higher incidence and better survival rate in secondary GF group. AR occurred in 11.6% in secondary GF, exhibited excellent prognosis.

Polymorphisms of MFGE8 are associated with susceptibility and clinical manifestations through gene expression modulation in Koreans with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is characterized by impaired clearance of apoptotic cells. Milk fat globule epidermal growth factor 8 (MFGE8) is a protein that connects αvß3 integrin on phagocytic macrophages with phosphatidylserine on apoptotic cells. We investigated whether genetic variation of the MFGE8 gene and serum MFGE8 concentration are associated with SLE. Single nucleotide polymorphisms (SNPs) were genotyped and serum concentrations were analyzed. The rs2271715 C allele and rs3743388 G allele showed higher frequency in SLE than in healthy subjects (HSs). Three haplotypes were found among 4 SNPs (rs4945, rs1878327, rs2271715, and rs3743388): AACG, CGCG, and CGTC. CGCG haplotype was significantly more common in SLE than in HSs. rs4945 was associated with the erythrocyte sedimentation rate and rs1878327 was associated with alopecia, C-reactive protein, complement 3, anti-dsDNA antibody, and high disease activity. rs2271715 and rs3743388 were associated with renal disease, cumulative glucocorticoid dose, and cyclophosphamide and mycophenolate mofetil use. Serum MFGE8 concentrations were significantly higher in SLE than in HSs. Furthermore, the levels of MFGE8 were significantly higher in SLE than HSs of the rs2271715 CC genotype. In conclusion, MFGE8 genetic polymorphisms are associated not only with susceptibility to SLE but also with disease activity through modulation of gene expression.

Endocytosing Escherichia coli as a Whole-Cell Biocatalyst of Fatty Acids.

Whole cell biocatalysts can be used to convert fatty acids into various value-added products. However, fatty acid transport across cellular membranes into the cytosol of microbial cells limits substrate availability and impairs membrane integrity, which in turn decreases cell viability and bioconversion activity. Because these problems are associated with the mechanism of fatty acid transport through membranes, a whole-cell biocatalyst that can form caveolae-like structures was generated to promote substrate endocytosis. Caveolin-1 ( CAV1) expression in Escherichia coli increased both the fatty acid transport rate and intracellular fatty acid concentrations via endocytosis of the supplemented substrate. Furthermore, fatty-acid endocytosis alleviated substrate cytotoxicity in E. coli. These traits attributed to bacterial endocytosis resulted in dramatically elevated biotransformation efficiencies in fed-batch and cell-recycle reaction systems when caveolae-forming E. coli was used for the bioconversion of ricinoleic acid (12-hydroxyoctadec-9-enoic acid) to ( Z)-11-(heptanoyloxy) undec-9-enoic acid. We propose that CAV1-mediated endocytosing E. coli represents a versatile tool for the biotransformation of hydrophobic substrates.