活性黑对黄孢原毛平革菌锰过氧化物酶的影响

观察了活性黑KN-B(Reactive Rlack KN-B,RB KN-B)对黄孢原毛平革菌(Phanerochaete chrysosporium)锰过氧化物酶(MnP)酶活力和菌丝超微结构的影响以及黄孢原毛平革菌对RB KN-B的降解.于P.chrysosporium培养液MnP酶活达最高前,分别加入质量浓度为50 mg/L,200 mg/L,350 mg/L和500 mg/L的RB KN-B.分光光度法检测培养液MnP酶活,电镜观察菌丝超微结构的影响,紫外-可见光谱法检测培养液中RB KN-B的降解.结果显示,1)与对照组相比,50 mg/L RBKN-B组的MnP酶活力增强,200 mg/L、350 mg/L和500 mg/L组的MnP酶活力均显著低于对照组;2)电镜观察显示,经RB KN-B作用后,菌丝细胞膜受损,细胞内含物减少,胞质浓缩,出现质壁分离现象,500mg/L组有大量细胞解体;3)紫外-可见光谱扫描显示,RB KN-B经黄孢原毛平革菌降解,可见光波段最大吸收峰由598 nm移至525 nm和556 nm,峰值减小,紫外波段的吸收峰由315 nm移至352 nm.结果显示,黄孢原毛平革菌对RB KN-B的反应类似机体对不良环境因子的应激反应,经历了诱导、抑制及衰退的过程;RB KN-B对黄孢原毛平革菌菌丝细胞超微结构的损伤随RB KN-B浓度增高而增强,表明RBKN-B对MnP酶活的抑制与黄孢原毛平革菌结构受损密切相关;黄孢原毛平革菌对RB KN-B具有一定的降解能力,其中MnP作为关键酶起了重要的作用.

Effects of reactive black on MnP activity of Phanerochaete chrysosporum

The purpose of this paper was to observe the effects of Reactive Black KN-B(RB KN-B) on Manganese-dependent Peroxidase(MnP) activity and ultrastructure of basidiomycete Phanerochaete chrysosporum.The paper also analyzed the degradation of RB KN-B.When RB KN-B was added to the cultivated system on the day before the MnP activity increased to its maximum level at the concentration of 50 mg/L,200 mg/L,350 mg/L and 500 mg/L.respectively,under the U-V spectrophotometer the MnP activity and RB KN-B content of the cultivated solution could be detected.Ultrastructure of hyphal cells could also be found under the transmission of electron microscope.Such results indicate that,at the concentration of 50 mg/L,RB KN-B was able to induce higher MnP activity.At 200 mg/L,350 mg/L and 500 mg/L,MnP was remarkably inhibited during the whole observation period.Therefore,the above results indicate that the co-cultured RB,KN-B P.chrysosporum may undergo a strong response during the three stages,that is,inducement,inhibition and exhaustion.Exposed to RB KN-B for 10 days,the ultrastructure of hyphal cells may evidently be damaged.The changes also include the plasmlemma shrinking from cellular wall and cytoplasm coagulating with the cellular autolysis observed at 500 mg/L.The above adverse effect would become more evident with the increase of RB KN-B concentration,which strongly suggests an association with the alteration of MnP activity.Hence,the results of absorbance spectrum of co-cultivated solution may indicate that with the treatment of P.chrysoporum,the wavelength of the maximum absorbance shifted from 598 nm to 525 nm and 556 nm and then the peak value would turn to decline.The above results also suggest that Phanerochaete chrysosporum is capable of degrading RB KN-B and MnP may therefore serve as the key enzyme involved in the biodegradation.