Screening And Identification Of Dye, PVA And DOP Degradating Fungi

Extensive usage of polymer chemistry materials such as industrial synthetic dyes andplastic products brought great harm to both environment and human healthy. The use oftraditional methods to deal with these compounds were limited because of high cost, lowefficiency although these methods made remarkable achievements. Therefore, it is valuable toresearch on biodegrading of polymer compound and screening and optimization of microbessuch as fungi which decompose synthetic dyes and plastic products are quite necessary.In this paper, two dyes of different structures, that is acidic dyes (acidic blue62, acidic blue40, acidic blue113, acidic blue193, acidic blue194and acidic red F3) and reactive dyes(reactive blue F4, reactive red24, reactive red11, reactive yellow18, reactive yellow2), werechosen as the objects. Finally, it turns out that sixteen fungi could degrade these dyes above.These strains acted on the dyes with the concentration of40mg/L and the rate ofdecolorization and degradation measurement results showed that: sixteen fungi acted onvarious dyes in different decolorization and degradation degrees, the highest decolorizationrate up to100%while the lowest is zero, while strains D, I-6C, J-1, F-2, jx-43, jx-44had agood broad spectrum decolorization on reactive and acidic dyes; Most of the identified fungisuch as strains D, F-2, MKLS261have good results on dyes degradation, the highestdegradation rate was up to100%;300nm to900nm wavelength scanning of dyes treated bymicroorganism show that the OD values of treated dyes reduces significantly in the maximumabsorption peak.These fully explained the molecular structure of the original dyes changedand microorganism could degrade dyes.ITS gene sequencing analysis combined with the morphological observation on the part ofthe dye degradation fungi, showed that there were Myrothecium verrucaria, Dictyosporiumzeylanicum, Colletotrichum dematium, Corynespora cassiicola; jx-432is Gilmanilla sp.nov.and MKLS261is Geotrichum sp.. The studies of the decomposition of plastic products used polyvinyl alcohol (PVA) andPhthalate-n-octyl phthalate (DOP) as the research object, selected the carbon source-free MSmedium, with PVA and DOP as sole carbon respectively for fungi screening.160strains fungiwere isolated from rotting plastic film mulch, screening and morphology of identificationresults showed that: strains could grow well on the above mediums are Fusarium proliferatum,Fusarium oxysporum, Fusarium equiseti, Fusarium moniliforme, Alternaria alternata andMyrothecium verrucaria.Aquatic saprophytic fungi screened that could degrade dyes had a broad dye spectrum.Moreover, the screened fungi that could decompose polyvinyl alcohol and Phthalate-n-octylphthalate distributed widely. These results lay the theoretical basis to further explore thebiological degradation of polyer compound.