The Study On Degradation Of Dyes By Immobilizing Pleurotus Eryngii

Pleurotus eryngii(P.eryngit)is a white-rot fungus belonging to Eumycophyta,Basidio mycotina,Hymenomycetes,Homobasidiomycetid-ae,Agaricales,Pleurotaceae,Pleurotus.As a kind of white rot fungi,it has been reported to have the capability to degrade lignin.With remarkably high redox-potention and substrate non-specificity,lignin-lytic enzymes involved in lignin biodegradation can oxidize various substrates including aromatic pollutants,heterocycle compounds,synthetic dyes and so on.Optimize decolorization reaction system of dyes by Pleurotus eryngii-Co007,the growth and ligninolytic enzymes production of Pleurotus eryngii-Co007 immobilized with immobilization carriers and their influence on decolorization of dyes were studied in this paper.Establish the kinetic model of degradation and decolorization of dyes by Pleurotus eryngii.Furthermore,The degradation products and potential degradation pathways of anthraquinone dye reactive brilliant blue KN-R and indigo were studied in this paper.It will clarify the potential applications of P.eryngii in the environmental protection,paper pulp bleaching,processing of food and other industrial applications.The optimum decolorization conditions of Congo red by Pleurotus eryngii=Co007 in liquid culture was investigated through single factor experiment of injecting time of dye,concentration of dye and temperature.When the concentration of azo dye Congo red is 15 mg/L,added on the fourth day in the process of buffer solution cultivation,the decolorization rate are 89%in 96 h.On that basis,Decolorization of dyes with different structures,the azo-dye got the best decolorizing effect among the selected of dyes,triphenylmethane dyes followed and the decolorization of anthraquinone dyes are most difficult,the difficulty of decolorization is related to molecular structure.investigated the effect of added carbon source glucose on the utilization of mycelium for decolorization.For the second batch of dye,additional glucose lg/L can improve the decolorization rate from 58.12%to 84.04%.to study the effect of carriers(nylon cloth,carborundum nylon,polyurethane foam,porous ceramic)on the growth,enzyme production and utilization of mycelium of Pleurotus eryngii-Co007 and the effects on the decoloration of dye.the result show that:in fermentation medium:the biomass in the immobilized culture were higher than control group,the nylon cloth was the best,1.2 times than control group,the added carriers can promote the synthesis of ligninolytic enzymes,in fermentation medium:The maximum activity of ligninolytic enzymes was 190.67 U/rnL in the immobilized culture which was added nylon cloth,1.9 times than control group.When the mycelia cultivated one times in buffer solution:the production of ligninolytic enzymes in buffer solution systems by Pleurotus eryngii-Co007 is better than in fermentation medium;the added adsorption-type carrier in addition to carborundum nylon all increase the enzymes production of reused mycelia and reduce the time needed to meet the peak of enzyme activity;the amount of ligninolytic enzymes produced by the mycelia used two times is much higher than that when the mycelia was used three times,the maximum activity of ligninolytic enzymes produced by the mycelia used two times was 306.41 U/mL on the 7th day in the immobilized culture which was added porous ceramic,1.22 times than control group,the peak of enzyme activity is 2 days in advance.for 3 dyes with different chemical structure,the decoloration system added carrier obtained higher decolorization rate than blank group.The bioadsorption of Pleurotus eryngii-co007 to the dye carplon red,Malachite Green and reactive brilliant blue KN-R accord with Langmuir adsorption isotherm.Furthermore Freundlich adsorption model may be used to represent the bioadsorption too.The process of adsorption and degradation of Pleurotus eryngii-Co007 for the three dyes accord with the first-order kinetic model.Reactive brilliant blue KN-R,a representative anthraquinone dyes,was chosen as degradation object by Pleurotus eryngii.The degradation products and potential degradation pathways of reactive brilliant blue KN-R were studied in this paper.The degradation products of brilliant blue KN-R were characterized by UV-visible,Fourier Transform Infrared Spectroscopy(FTIR),HPLC and GC/MS.And their toxicity with respect to hydrocotyle vulgaris was evaluated.The results showed that the degradation products of reactive brilliant blue KN-R included malonic acid,phthalic acid and other compounds with benzene ring,and it had no influence on the growth of hydrocotyle vulgaris.Using the same analytical method to deal with Indigo,And its toxicity with respect to lotus seed was evaluated.The degradation products of indigo included salicylic acid,aniline and other compounds with benzene ring.The Pleurotus eryngii-Co007 exhibited significant ability to degrade indigo,Polycyclic structures of indigo were cracked in the degradation process,and benzodiazepines degradation products were formed,generated some degradation products with benzene ring,degradation liquid toxicity was far less than the dye solution.