Decolorization Of Textile Waster Water By Phanerochaete Chrysosporium And It's Peroxidases

In this article we studied the fermentation conditions of Phanerochaete chrysosporium for the MnP(manganese peroxidase) and LiP(lignin peroxidase) production. The results indicate that with N-limited medium, 37℃ and 150 rpm shaking incubation the LiP achieved the maximum activity on day 6 and MnP reached the maximum activity on day 7. Furthermore, changing the culture from shaking to static incubation on day 6 would redound to maintenance and increase of the enzymes' activity.SDS-PAGE of the fermentation liquid of Phanerochaete chrysosporium showed that there were three proteins close to each other on the gel with molecular weight of approximately 37kD, 38kD and 40kD. Purified by superfiltrate, DEAE-sephadex A-50 ion exchange chromatography and dialysis, the molecular of MnP and LiP were estimated 40kD and 37kD by SDS-PAGE.The optimum temperature of MnP and LiP were 35 ℃ and 40℃ respectively. The activity-half-lost temperature for MnP and LiP were 45℃ and 40℃ respectively. The optimum pH of MnP and LiP were 4.6 and 2.8 respectively. MnP was stable in the pH range of 4.0-7.0, and LiP was stable in the pH range of 2.2-5.2. We had investigated 12 kind of mental ions, among which only Fe3+and Mn2+ inhibited the activity of LiP, while the former inhibited almost all the activity, other ions all had more or less promoted effects on LiP; To MnP, almost all the ions investigated had inhibited effects on it, among them Fe3+ and Cu2+ inhibited 90% activity, while others had less effects, only Fe2+ and Mn2+ could promoted the activity of MnP.Study of the factors which affected the decolorization of textile waster water by Phanerochaete chrysosporium revealed that the pH, mycelium's age and diluted multiple had greater effects on the decolorization rate, while the rotate speed and temperature had less effects. Greatest decolorization rate had obtained with three-days -old mycelium, pH3.4-4.6, 38癈, 150-180rpm. Crude enzyme liquid alone had no function in decolorization, while mycelium had great function in decolorization. When added H2O2 and veratryl alcohol into the crude enzyme liquid, the decolorization rate had increased from 0% to more than 30%, so the H2O2 and veratryl alcohol played roles in the decolorization.