Exopolysaccharides of Paenibacillus polymyxa: A review.

Paenibacillus polymyxa (P. polymyxa) is a member of the genus Paenibacillus, which is a rod-shaped, spore-forming gram-positive bacterium. P. polymyxa is a source of many metabolically active substances, including polypeptides, volatile organic compounds, phytohormone, hydrolytic enzymes, exopolysaccharide (EPS), etc. Due to the wide range of compounds that it produces, P. polymyxa has been extensively studied as a plant growth promoting bacterium which provides a direct benefit to plants through the improvement of N fixation from the atmosphere and enhancement of the solubilization of phosphorus and the uptake of iron in the soil, and phytohormones production. Among the metabolites from P. polymyxa, EPS exhibits many activities, for example, antioxidant, immunomodulating, anti-tumor and many others. EPS has various applications in food, agriculture, environmental protection. Particularly, in the field of sustainable agriculture, P. polymyxa EPS can be served as a biofilm to colonize microbes, and also can act as a nutrient sink on the roots of plants in the rhizosphere. Therefore, this paper would provide a comprehensive review of the advancements of diverse aspects of EPS from P. polymyxa, including the production, extraction, structure, biosynthesis, bioactivity and applications, etc. It would provide a direction for future research on P. polymyxa EPS.

Resource utilization of hazardous solid waste blast furnace dust: Efficient wet desulfurization and metal recovery.

Hazardous solid waste blast furnace dust (BFD) is rich in valuable metal components such as iron (Fe), zinc (Zn), manganese (Mn), and its recycling or harmless treatment is a major challenge. This paper creatively proposes the strategy of "treating waste with waste" by using BFD for desulfurization. The experimental results show that BFD slurry can achieve high-efficiency desulfurization and recovery of Zn resources. The characterization results indicate that ZnO and Fe2O3 in BFD slurry are the main active components of desulfurization, and the consumption of active components is the main reason for the decline of BFD slurry activity. Further semi-continuous experimental research shows that Zn, Fe, and Mn ions in BFD slurry play a crucial role in the catalytic oxidation of sulfur dioxide (SO2). Additionally, the effects of reaction temperature, stirring speed, inlet SO2 concentration, and inlet gas flow rate on the leaching rate of Zn and Fe were investigated. Under optimal conditions (SO2 concentration = 3000 mg‧m-3, reaction temperature = 40 °C, inlet gas flow rate = 300 mL‧min-1, solid-liquid ratio = 0.5 g/300 mL, stirring speed = 600 rpm), the desulfurization rate reaches 100%, and the maximum leaching rate of Zn can reach 44.6%. Based on the experimental and characterization results, the possible mechanism of BFD slurry desulfurization was proposed. This study provides a reference for the application of BFD in the field of wet desulfurization.

Removal of SO2 from flue gas using blast furnace dust as an adsorbent.

To control the SO2 emission and achieve the target of "waste controlled by waste", a novel desulfurization method with blast furnace dust slurry was proposed. The effects of reaction temperature, oxygen concentration, and solid-liquid ratio on SO2 removal efficiency were investigated. The optimal conditions were reaction temperature of 35 ℃, oxygen concentration of 10 vol.%, and solid-liquid ratio of 0.5 g/300 mL. Under the optimal conditions, the desulfurization efficiency reached 100% for 4 h. Response surface methodology (RSM) results showed that oxygen concentration significantly influenced the SO2 removal efficiency. Finally, the possible desulfurization mechanism of blast furnace dust was proposed based on the EDX, XRD, SEM-EDS, ICP, and IC. The blast furnace dust (main components are CaZn8(SO4)2(OH)12Cl2·(H2O)9, Mn6.927Si6O15·(OH)8, ZnO, Fe2O3) reacted with H+ to form Zn2+, Fe3+, and Mn2+ which shows a key effect on the SO2 liquid catalytic oxidation. This study provides a promising, feasible, and low-cost desulfurization technology by reusing blast furnace dust.

Aberrant nuclear lamina contributes to the malignancy of human gliomas.

Glioma is the most common type of tumor in the central nervous system, accounting for around 80% of all malignant brain tumors. Previous studies showed a significant association between nuclear morphology and the malignant progress of gliomas. By virtue of integrated proteomics and genomics analyses as well as experimental validations, we identify three nuclear lamin genes (LMNA, LMNB1, and LMNB2) that are significantly upregulated in glioma tissues compared with normal brain tissues. We show that elevated expressions of LMNB1, LMNB2, and LMNA in glioma cells are highly associated with the rapid progression of the disease and the knockdown of LMNB1, LMNB2, and LMNA dramatically suppresses glioma progression in both in vitro and in vivo mouse models. Moreover, the repression of glioma cell growth by lamin knockdown is mediated by the pRb-mediated G1-S inhibition. On the contrary, overexpression of lamins in normal human astrocytes dramatically induced nuclear morphological aberrations and accelerated cell growth. Together, our multi-omics-based analysis has revealed a previously unrecognized role of lamin genes in gliomagenesis, providing a strong support for the key link between aberrant tumor nuclear shape and the survival of glioma patients. Based on these findings, lamins are proposed to be potential oncogene targets for therapeutic treatments of brain tumors.

Chromosomal aberration arises during somatic reprogramming to pluripotent stem cells.

BACKGROUND: Reprogramming somatic cells to induced pluripotent stem cells (iPSCs) has opened new therapeutic possibilities. However, karyotypic abnormalities detected in iPSCs compromised their utility, especially chromosomal aberrations found at early passages raised serious safety concerns. The mechanism underlying the chromosomal abnormality in early-passage iPSCs is not known. METHODS: Human dermal fibroblasts (HDFs) were stimulated with KMOS (KLF4, cMYC, OCT4 and SOX2) proteins to enhance their proliferative capacity and many vigorous clones were obtained. Clonal reprogramming was carried out by KMOS mRNAs transfection to confirm the 'chromosomal mutagenicity' of reprogramming process. Subculturing was performed to examine karyotypic stability of iPSCs after the re-establishment of stemness. And antioxidant N-acetyl-cysteine (NAC) was added to the culture medium for further confirmming the mutagenicity in the first few days of reprogramming. RESULTS: Chromosomal aberrations were found in a small percentage of newly induced iPS clones by reprogramming transcription factors. Clonal reprogramming ruled out the aberrant chromosomes inherited from rare karyotypically abnormal parental cell subpopulation. More importantly, the antioxidant NAC effectively reduced the occurrence of chromosomal aberrations at the early stage of reprogramming. Once iPS cell lines were established, they restored karyotypic stability in subsequent subculturing. CONCLUSIONS: Our results provided the first line of evidence for the 'chromosomal mutagenicity' of reprogramming process.