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The discharge of wastewater from textile industries into aquatic bodies has severe health and environmental impacts. Textile industries generate huge amounts of effluents containing hazardous toxic dyes. Anthraquinone (AQ) dyes containing AQ chromophore groups are the second most important class of nondegradable textile dyes, preceded by azo dyes. Despite their prevalence, biodegradation of AQ dyes has not yet been completely understood because of their complex and stable structures. Currently, microbiological approaches to treating dyeing wastewater are considered economical and feasible, and reports regarding fungal degradation of AQ dyes are increasing. Structures and classification of AQ dyes were summarized in this study along with degradative fungi, and their enzyme systems with influencing factors and possible mechanisms of AQ mycoremediation were explored. Furthermore, the existing problems and present research progress were discussed. Finally, the key points with future research directions were presented.
RESUMO
ABSTRACT: In the present study, artificial neural network (ANN) modelling coupled with particle swarm optimization (PSO) algorithm was used to optimize the process variables for enhanced low density polyethylene (LDPE) degradation by Curvularia lunata SG1. In the non-linear ANN model, temperature, pH, contact time and agitation were used as input variables and polyethylene bio-degradation as the output variable. Further, on application of PSO to the ANN model, the optimum values of the process parameters were as follows: pH = 7.6, temperature = 37.97 °C, agitation rate = 190.48 rpm and incubation time = 261.95 days. A comparison between the model results and experimental data gave a high correlation coefficient ([Formula: see text]). Significant enhancement of LDPE bio-degradation using C. lunata SG1by about 48 % was achieved under optimum conditions. Thus, the novelty of the work lies in the application of combination of ANN-PSO as optimization strategy to enhance the bio-degradation of LDPE.
RESUMO
Bacterial samples isolated from the upper respiratory tract of a healthy broiler chicken and a wild chicken suffering from influenza which were collected locally revealed proteolytic activity as detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and zymogram analysis. Among five protease producing strains screened, one was selected as promising protease producer. The activity of the protease produced by this organism is stable up to 620C. Optimum yield was achieved after 19 hours of culture, at pH 9.0 and 450C. The desired protein was precipitated from the crude extract by using ammonium sulfate (60%) followed by dialysis and purified by Ion-exchange chromatography. Further investigations are needed to know about the structure elucidation of the purified protein for industrial exploitation.