Efficacy of fungal decolorization of a mixture of dyes belonging to different classes

Dyes are the most difficult constituents to remove by conventional biological wastewater treatment. Colored wastewater is mainly eliminated by physical and chemical procedures, which are very expensive and have drawbacks. Therefore, the advantage of using biological processes, such as the biotransformation of dyes, is that they may lead to complete mineralization or formation of less toxic products. To prove the possibility of using fungal processes for decolorization and other applications, the analysis of the toxicity of the processes' products is required. The decolorization of the mixture of two dyes from different classes - triphenylmethane brilliant green and azo Evans blue (GB - total concentration 0.08 g/L, proportion 1:1 w/w) - by Pleurotus ostreatus (BWPH and MB), Gloeophyllum odoratum (DCa), RWP17 (Polyporus picipes) and Fusarium oxysporum (G1) was studied. Zootoxicity (Daphnia magna) and phytotoxicity (Lemna minor) changes were estimated at the end of the experiment. The mixture of dyes was significantly removed by all the strains that were tested with 96 h of experimental time. However, differences among strains from the same species (P. ostreatus) were noted. Shaking improved the efficacy and rate of the dye removal. In static samples, the removal of the mixture reached more than 51.9% and in shaken samples, more than 79.2%. Tests using the dead biomass of the fungi only adsorbed up to 37% of the dye mixture (strain BWPH), which suggests that the process with the living biomass involves the biotransformation of the dyes. The best results were reached for the MB strain, which removed 90% of the tested mixture under shaking conditions. Regardless of the efficacy of the dye removal, toxicity decreased from class V to class III in tests with D. magna. Tests with L. minor control samples were classified as class IV, and samples with certain strains were non-toxic. The highest phytotoxicity decrease was noted in shaken samples where the elimination of dye mixture was the best.

Bioremediation of dyes by fungi isolated from contaminated dye effluent sites for bio-usability

Biodegradation and detoxification of dyes, Malachite green, Nigrosin and Basic fuchsin have been carried out using two fungal isolates Aspergillus niger, and Phanerochaete chrysosporium, isolated from dye effluent soil. Three methods were selected for biodegradation, viz. agar overlay and liquid media methods; stationary and shaking conditions at 25 °C. Aspergillus niger recorded maximum decolorization of the dye Basic fuchsin (81.85%) followed by Nigrosin (77.47%), Malachite green (72.77%) and dye mixture (33.08%) under shaking condition. Whereas, P. chrysosporium recorded decolorization to the maximum with the Nigrosin (90.15%) followed by Basic fuchsin (89.8%), Malachite green (83.25%) and mixture (78.4%). The selected fungal strains performed better under shaking conditions compared to stationary method; moreover the inoculation of fungus also brought the pH of the dye solutions to neutral from acidic. Seed germination bioassay study exhibited that when inoculated dye solutions were used, seed showed germination while uninoculated dyes inhibited germination even after four days of observation. Similarly, microbial growth was also inhibited by uninoculated dyes. The excellent performance of A. niger and P. chrysporium in the biodegradation of textile dyes of different chemical structures suggests and reinforces the potential of these fungi for environmental decontamination.

Sentinel Node Biopsy as an Indicator for Pelvic Nodes Dissection in Early Stage Cervical Cancer

The purpose of this study was to investigate the feasibility of sentinel node frozen biopsy to minimize the extensive pelvic lymph nodes dissection in early stage cervical cancer patients on the basis that the risk of skip metastasis to the paraaortic area is negligible. Twenty-six patients with early stage cervical cancer were enrolled in this study. Technetium-99m colloid albumin (Tc(99m)) was injected intradermally around the tumor for allowing preoperative lymphoscintigraphy and intraoperative hand-held gama probe detection of seninel nodes. For visual detection, isosulfan blue dye was injected into the peritumoral sites before peritoneal opening. Postoperative morbidity and negative predictive value were the endpoints of this study. The 26 patients, ranging in age from 32 to 71 yr, underwent intraoperative sentinel nodes mapping. All the patients underwent complete pelvic lymph nodes dissection including para-aortic nodes. There was one case with positive non-sentinel nodes despite the negative sentinel node by frozen biopsy (negative predictive value, 95.2%). This new technique of sentinel node mapping is safe and simple to perform. Further clinical trials using the combination of Tc(99m) and isosulfan blue dye are warranted and this technique will make a true advance for less aggressive management of patients with early stage cervical cancer.

Elimination of Basic Fuchsin and Other Dyes from the Pancreas

Twenty dyes which previously have been claimed to be excreted in pancreatic juice were reinvestigated to determine to what extent they could be eliminated through the pancreas. Exogenous secretin or cholecysto-kinin-pancreozymin(CCK-PZ) stimuli were used in dogs which had been given intravenous dye solutions at the rate of 1mg/min. In this experiment among the twenty dyes, only six were found to be eliminated through the pancreas. The intensity of dye color in pancreatic juice was estimated photometrically or macroscopically. The dye color intensity decreased as follows; basic fuchsin, acridine red, new fuchsin, rhodamin B, phenol red and rhodamin 6G. Basic fuchsin consistently appeared in CCK-PZ stimulated juice. However, it was seen in only a scant amount or not at all in juice stimulated by purified Vitrum (Sweden) secretin. Similar findings were observed in cats and conscious pigs. The content of basic fuchsin in pancreatic juice was more related to changes in the enzyme concentration than to other components. The chloride content of the juice was related to the amylase or basic fuchsin secretion. However, the chloride content was inversely related to the secreted volume. Vagal stimulation or the administration of parasympathomimetics produced a juice rich in enzyme content, but the dye response to vagal stimulation was weak. Usually the volume of secreted pancreatic juice following stimulation by Boots (England) secretin is greater than stimulated by purified Vitrum preparation. Basic fuchsin was slightly reduced during its elimination from pancreas or when present in alkaline pancreatic juice. Adding acid and formaldehyde revived the color. The acridine red and other pyronine dyes caused the juice to fluorescence. This effect lasted over 24 hours.