Azo dyes containing effluents from different industries pose threats to the environment. Though there are physico-chemical methods to treat such effluents, bioremediation is considered to be the best eco-compatible technique. In this communication, we discuss the decolorization potentiality of five azo dyes by Podoscypha elegans (G. Mey.) Pat., a macro-fungus, found growing on the leaf-litter layer of Bethuadahari Wildlife Sanctuary in West Bengal, India. The fungus exhibited high laccase and very low manganese peroxidase activities under different culture conditions. Decolorization of five high-molecular weight azo dyes, viz., Orange G, Congo Red, Direct Blue 15, Rose Bengal and Direct Yellow 27 by the fungus was found to be positive in all cases. Maximum and minimum mean decolorization percentages were recorded in Rose Bengal (70.41%) and Direct Blue 15 (24.8%), respectively. This is the first record of lignolytic study and dye decolorization by P. elegans.
Azo Compounds ; Biodegradation, Environmental ; Citrus sinensis ; Congo Red ; Fungi ; India ; Laccase* ; Manganese ; Peroxidase ; Rose Bengal

BACKGROUND AND OBJECTIVELeukemic microenvironment has a major role in the progression of leukemia. Leukemic cells can induce reversible changes in microenvironmental components, especially the stromal function which results in improved growth conditions for maintaining the malignant leukemic cells. This study aimed to investigate the survival advantage of leukemic cells over normal hematopoietic cells in stromal microenvironment in long term.

METHODSThe mice were injected intraperitoneally with N-N' ethylnitrosourea (ENU) to induce leukemia; the mice received injection of normal saline were used as control. At 180 days after ENU induction, the mice were killed and the bone marrows were cultured for 19 days. Colony-forming assays were used to analyze the formation of various cell colonies. The expression of Sca-1, CD146, VEGFR2, CD95, pStat3, pStat5, and Bcl-xL in marrow cells were detected by flow cytometry.

RESULTSLong-term leukemic bone marrow culture showed abnormal elongated stromal fibroblasts with almost absence of normal hematopoietic cells. Adherent cell colonies were increased, but CFU-F and other hematopoietic cell colonies were significantly decreased in leukemia group (P<0.001). Primitive progenitor-specific Sca-1 receptor expression was decreased with subsequent increased expression of CD146 and VEGFR-2 in leukemic bone marrow cells. Decreased Fas antigen expression with increased intracellular pStat3, pStat5 and Bcl-xL proteins were observed in leukemic bone marrow cells.

CONCLUSIONSStromal microenvironment shows altered morphology and decreased maturation in leukemia. Effective progenitor cells are decreased in leukemia with increased leukemia-specific cell population. Leukemic microenvironment plays a role in promoting and maintaining the leukemic cell proliferation and survivability in long term.

Animals ; Antigens, Ly ; metabolism ; Bone Marrow Cells ; metabolism ; pathology ; CD146 Antigen ; metabolism ; Cell Count ; Cells, Cultured ; Colony-Forming Units Assay ; Erythroid Precursor Cells ; metabolism ; pathology ; Ethylnitrosourea ; Female ; Fibroblasts ; metabolism ; pathology ; Granulocyte-Macrophage Progenitor Cells ; metabolism ; pathology ; Granulocytes ; metabolism ; pathology ; Hematopoiesis ; Hematopoietic Stem Cells ; metabolism ; pathology ; Leukemia ; chemically induced ; metabolism ; pathology ; Male ; Membrane Proteins ; metabolism ; Mice ; Myeloid Progenitor Cells ; metabolism ; pathology ; Phenotype ; STAT3 Transcription Factor ; metabolism ; STAT5 Transcription Factor ; metabolism ; Tumor Microenvironment ; physiology ; Vascular Endothelial Growth Factor Receptor-2 ; metabolism ; bcl-X Protein ; metabolism ; fas Receptor ; metabolism