Explorations and Applications of Enzyme-linked Bioremediation of Synthetic Dyes

Extensive use of synthetic dyes and their subsequent release in industrial wastewater is a growing environmental problem. These dyes are recalcitrant in nature, and some dyes are also well established to be potentially carcinogenic and mutagenic as well as genotoxic. Research efforts have been devoted to develop new, low-cost, and eco-friendly treatments capable of reducing and even eliminating synthetic dye compounds from the environment. Enzymatic approach has attracted much interest recently in the decolorization of textile and other industrially important dyes from wastewater as an alternative strategy to conventional chemical, physical, and biological treatments, which pose serious limitations. In this chapter, the accumulated research data on the potential of the oxidoreductive enzymes—high redox potential peroxidases (lignin peroxidase [LiP], EC 1.11.1.14; manganese peroxidase [MnP], EC 1.11.1.13; dye decolorizing peroxidase [DyP], EC 1.11.1.19; and versatile peroxidases [VP], EC 1.11.1.16), laccases (benzenediol–oxygen oxidoreductase, EC 1.10.3.2), polyphenol oxidases (EC 1.14.18.1), and azoreductases (azobenzene reductases, EC 1.7.1.6)—that have been exploited in the decolorization and degradation of synthetic dyes are presented. An overview of enzyme technology, including the importance of redox mediators for enhanced range of substrates and efficiency of degradation, current biodegradation applications, and suggestions to overcome the limitations to these proteins’ large scale and efficient use, is made. Different strategies currently being used and future prospects for the potential use of genetic engineering techniques to improve the performance of these oxidoreductases in terms of stability, selectivity, and catalytic activity in dye bioremediation technologies are also explored

An Open-labeled, Multicenter Phase II Study of Tamibarotene in Patients with Steroid-refractory Chronic Graft-versus-Host Disease

Chronic graft-versus-host disease (GVHD) is a major cause of late death and morbidity following allogeneic hematopoietic cell transplantation (HSCT). Retinoic acid (tamibarotene) exerts multiple effects on cell differentiation and is clinically used for the treatment of acute promyelocytic leukemia. Tamibarotene down-regulates both Th1 and Th17 differentiation in donor T cells after allogeneic HSCT, resulting in attenuation of experimental chronic GVHD. Based on preclinical data, we have launched a phase II study of tamibarotene in patients with steroid-refractory chronic GVHD. This study will clarify whether tamibarotene can exert beneficial effects in patients with steroid-refractory chronic GVHD

Advantages of peripheral blood stem cells from unrelated donors versus bone marrow transplants in outcomes of adult acute myeloid leukemia patients

[Background aims] In allogeneic stem cell transplantation, unrelated donors are chosen in cases where appropriate related donors are not available. Peripheral blood stem cells (PBSCs) are more often selected as a graft source than bone marrow (BM). However, the prognostic benefits of PBSCs versus BM transplants from unrelated donors have not been carefully examined in patients with acute myeloid leukemia (AML). This study compared outcomes of adult AML patients who underwent unrelated PBSC and BM transplantation, evaluating post-transplant complications, including engraftment, graft-versus-host disease (GVHD) and infections, and determined subgroups of patients who are most likely to benefit from unrelated PBSCs compared with BM transplants. [Methods] The authors analyzed 2962 adult AML patients who underwent unrelated PBSC or BM transplants between 2011 and 2018 (221 PBSC and 2741 BM) using the Japanese nationwide registry database, in which graft source selection is not skewed toward PBSCs. [Results] In 49.7% of patients, disease status at transplantation was first complete remission (CR1). In 57.1% of cases, HLA-matched donors were selected. Myeloablative conditioning was performed in 75.1% of cases, and anti-thymocyte globulin (ATG) was added to conditioning in 10.5%. Multivariate analyses showed a trend toward favorable non-relapse mortality (NRM) in PBSC recipients compared with BM recipients (hazard ratio [HR], 0.731, P = 0.096), whereas overall survival (OS) (HR, 0.959, P = 0.230) and disease-free survival (DFS) (HR, 0.868, P = 0.221) were comparable between PBSC and BM recipients. Although the rate of chronic GVHD (cGVHD) was significantly higher in PBSC patients (HR, 1.367, P = 0.016), NRM was not increased, mainly as a result of significantly reduced risk of bacterial infections (HR, 0.618, P = 0.010), reflecting more prompt engraftments in PBSC recipients. Subgroup analyses revealed that PBSC transplantation was advantageous in patients transplanted at CR1 and in those without ATG use. PBSC recipients experienced significantly better OS and/or DFS compared with BM recipients in this patient group. [Conclusions] The authors' results confirmed the overall safety of unrelated PBSC transplantation for adult AML patients and suggested an advantage of PBSCs, especially for those in CR1. Further optimization of the prophylactic strategy for cGVHD is required to improve the overall outcome in transplantation from unrelated PBSC donors

Expression of aspartyl protease and C3HC4-type RING zinc finger genes are responsive to ascorbic acid in Arabidopsis thaliana

Ascorbate (AsA) is a redox buffer and enzyme cofactor with various proposed functions in stress responses and growth. The aim was to identify genes whose transcript levels respond to changes in leaf AsA. The AsA-deficient Arabidopsis mutant vtc2-1 was incubated with the AsA precursor L-galactono-1,4-lactone (L-GalL) to increase leaf AsA concentration. Differentially expressed genes screened by DNA microarray were further characterized for AsA responsiveness in wild-type plants. The analysis of 14 candidates by real-time PCR identified an aspartyl protease gene (ASP, At1g66180) and a C3HC4-type RING zinc finger gene (AtATL15, At1g22500) whose transcripts were rapidly responsive to increases in AsA pool size caused by L-GalL and AsA supplementation and light. Transgenic Arabidopsis plants expressing an AtATL15 promoter::luciferase reporter confirmed that the promoter is L-GalL, AsA, and light responsive. The expression patterns of ASP and AtATL15 suggest they have roles in growth regulation. The promoter of AtATL15 is responsive to AsA status and will provide a tool to investigate the functions of AsA in plants further

Translocation and the alternative D-galacturonate pathway contribute to increasing the ascorbate level in ripening tomato fruits together with the D-mannose/L-galactose pathway

The D-mannose/L-galactose pathway for the biosynthesis of vitamin C (L-ascorbic acid; AsA) has greatly improved the understanding of this indispensable compound in plants, where it plays multifunctional roles. However, it is yet to be proven whether the same pathway holds for all the different organs of plants, especially the fruit-bearing plants, at different stages of development. Micro-Tom was used here to elucidate the mechanisms of AsA accumulation and regulation in tomato fruits. The mRNA expression of the genes in the D-mannose/L-galactose pathway were inversely correlated with increasing AsA content of Micro-Tom fruits during ripening. Feeding L-[6-14C]AsA to Micro-Tom plants revealed that the bulk of the label from AsA accumulated in the source leaf was transported to the immature green fruits, and the rate of translocation decreased as ripening progressed. L-Galactose feeding, but neither D-galacturonate nor L-gulono-1,4-lactone, enhanced the content of AsA in immature green fruit. On the other hand, L-galactose and D-galacturonate, but not L-gulono-1,4-lactone, resulted in an increase in the AsA content of red ripened fruits. Crude extract prepared from insoluble fractions of green and red fruits showed D-galacturonate reductase- and aldonolactonase-specific activities, the antepenultimate and penultimate enzymes, respectively, in the D-galacturonate pathway, in both fruits. Taken together, the present findings demonstrated that tomato fruits could switch between different sources for AsA supply depending on their ripening stages. The translocation from source leaves and biosynthesis via the D-mannose/L-galactose pathway are dominant sources in immature fruits, while the alternative D-galacturonate pathway contributes to AsA accumulation in ripened Micro-Tom fruits

Iron–platinum–arsenide superconductors Ca₁₀(Pt_nAs₈)(Fe_2−xPt_xAs₂)₅

An overview of the crystal structures and physical properties of the recently discovered iron-platinum-arsenide superconductors, Ca-10(PtnAs8)(Fe2-xPtxAs2)(5) (n = 3 and 4), which have a superconducting transition temperature up to 38K, is provided. The crystal structure consists of superconducting Fe2As2 layers alternating with platinum-arsenic layers, PtnAs8. The upper critical field H-c2, hydrostatic pressure dependence of superconducting transition temperature T-c, and normal-state magnetic susceptibility are reported

Insights into Land Plant Evolution Garnered from the Marchantia polymorpha Genome.

The evolution of land flora transformed the terrestrial environment. Land plants evolved from an ancestral charophycean alga from which they inherited developmental, biochemical, and cell biological attributes. Additional biochemical and physiological adaptations to land, and a life cycle with an alternation between multicellular haploid and diploid generations that facilitated efficient dispersal of desiccation tolerant spores, evolved in the ancestral land plant. We analyzed the genome of the liverwort Marchantia polymorpha, a member of a basal land plant lineage. Relative to charophycean algae, land plant genomes are characterized by genes encoding novel biochemical pathways, new phytohormone signaling pathways (notably auxin), expanded repertoires of signaling pathways, and increased diversity in some transcription factor families. Compared with other sequenced land plants, M. polymorpha exhibits low genetic redundancy in most regulatory pathways, with this portion of its genome resembling that predicted for the ancestral land plant. PAPERCLIP