Biotransformation and Detoxification of Xylidine Orange Dye Using Immobilized Cells of Marine-Derived Lysinibacillus sphaericus D3.

Lysinibacillus sphaericus D3 cell-immobilized beads in natural gel sodium alginate decolorized the xylidine orange dye 1-(dimethylphenylazo)-2-naphthol-6-sulfonic acid sodium salt in the laboratory. Optimal conditions were selected for decolorization and the products formed were evaluated for toxicity by disc diffusion assay against common marine bacteria which revealed the non-toxic nature of the dye-degraded products. Decolorization of the brightly colored dye to colorless products was measured on an Ultra Violet-Vis spectrophotometer and its biodegradation products monitored on Thin Layer Chromatographic plate and High Performance Liquid Chromatography (HPLC). Finally, the metabolites formed in the decolorized medium were characterized by mass spectrometry. This analysis confirms the conversion of the parent molecule into lower molecular weight aromatic phenols and sulfonic acids as the final products of biotransformation. Based on the results, the probable degradation products of xylidine orange were naphthol, naphthylamine-6-sulfonic acid, 2-6-dihydroxynaphthalene, and bis-dinaphthylether. Thus, it may be concluded that the degradation pathway of the dye involved (a) reduction of its azo group by azoreductase enzyme (b) dimerization of the hydrazo compound followed by (c) degradation of monohydrazo as well as dimeric metabolites into low molecular weight aromatics. Finally, it may be worth exploring the possibility of commercially utilizing L. sphaericus D3 for industrial applications for treating large-scale dye waste water.

Impact of prepubertal bovine ovarian tissue pre-freeze holding duration on follicle quality.

Ovarian tissue cryopreservation prior to gonadotoxic treatment is the only recommended option for fertility preservation in prepubertal girls. Due to the technical complexity of this technique, limited number of centres across the world are equipped to offer the facility. Hence, the retrieved ovarian tissue needs to be maintained at hypothermic temperature (4 °C) for long time during shipment. The time taken between tissue retrieval and cryopreservation could influence the functionality of cells during fertility restoration. This study explored the tissue integrity and follicle quality of ovarian cortical slices subjected to pre-freeze holding for various time durations in vitro. Prepubertal bovine ovarian tissue from < 12 months old animals were handled at hypothermic holding (4 °C) for 0, 24, 48 and 72 h. The tissues were assessed for follicle viability through confocal analysis of live-dead labelled samples, and follicle quality and tissue integrity through histology. Results have shown that follicle viability, and overall follicle quality were not significantly affected at the end of 72 h hypothermic holding. Though, the observation reassures extended hypothermic holding prior to freezing, findings need to be validated in human tissue prior to use in clinical fertility preservation programs.