Two Manganese Peroxidases and a Laccase ofTrametes polyzonaKU-RNW027 with Novel Properties for Dye and Pharmaceutical Product Degradation in Redox Mediator-Free System

Abstract

Two manganese peroxidases (MnPs), MnP1 and MnP2, and a laccase, Lac1, were purified from Trametes polyzona KU-RNW027. Both MnPs showed high stability in organic solvents which triggered their activities. Metal ions activated both MnPs at certain concentrations. The two MnPs and Lac1, played important roles in dye degradation and pharmaceutical products deactivation in a redox mediator-free system. They completely degraded Remazol brilliant blue (25 mg/L) in 10-30 min and showed high degradation activities to Remazol navy blue and Remazol brilliant yellow, while Lac1 could remove 75% of Remazol red. These three purified enzymes effectively deactivated tetracycline, doxycycline, amoxicillin, and ciprofloxacin. Optimal reaction conditions were 50 C and pH 4.5. The two MnPs were activated by organic solvents and metal ions, indicating the efficacy of using T. polyzona KU-RNW027 for bioremediation of aromatic compounds in environments polluted with organic solvents and metal ions with no need for redox mediator supplements.

Characterization of a Novel Laccase LAC-Yang1 from White-Rot Fungus Pleurotus ostreatus Strain Yang1 with a Strong Ability to Degrade and Detoxify Chlorophenols

“…Our results also show the good stability of LAC-Yang1 under highly alkaline conditions. However, different from the previous research [ 37 ], the stability of LAC-Yang1 after incubation at pH 9.0–11.0 for a longer time (up to 7 days) was investigated in our study. LAC-Yang1 still possessed 71.57%, 67.58%, and 64.50% of its original activity after long-term incubation (7 days) at pH 9, 10, and 11, respectively.…”

“…The residual activity of the laccase from P. ostreatus K16-2 was about 90% after incubation at pH 9.0 for 20 h. However, the previous study only detected residual laccase activity after 20 h of incubation at pH 9.0, 10.0, and 11.0 and no stability after a longer duration of incubation (such as 24 h or more) under strong alkaline conditions. The stability of the laccase from P. ostreatus K16-2 after incubation at pH 9.0–11.0 for a longer time (such as 72 h and 7 days) was not studied in the previous research [ 37 ]. Our results also show the good stability of LAC-Yang1 under highly alkaline conditions.…”

“…Comparison of the effect of EDTA on the activity of LAC-Yang1 and other reported laccases was summarized in Table 8 . The results show the superior resilience of LAC-Yang1 to EDTA compared with the laccases from Trametes polyzona [ 38 ], P. ostreatus K16-2 [ 37 ], and P. ostreatus strain 10969 [ 31 ]. The resistance of LAC-Yang1 to EDTA was significantly stronger than that of other laccases reported previously [ 31 , 37 , 38 ].…”

Light Regulation of Two New Manganese Peroxidase-Encoding Genes in Trametes polyzona KU-RNW027

“…Degenerate primers for mnp were designed according to LC-MS/MS based protein fingerprints of MnPs [ 22 ], whereas degenerate primers for lac were designed based on the conserved nucleotide sequence of lac from related species in genus Trametes and are listed in Table S1 . The fragments were amplified by PCR with LA Taq DNA polymerase (Takara Bio, Kusatsu, Japan).…”

“…Trametes polyzona KU-RNW027 is a white rot fungus that exhibits high manganese peroxidase (MnP) and laccase activities with efficacy on dyes and pharmaceutical product degradation [ 21 , 22 ]. Here, the aim was to investigate the enzyme-encoding genes in the ligninolytic system of Trametes polyzona KU-RNW027 and how they regulate enzyme production and enzyme-gene expression under conditions of illumination.…”