Selection of High Laccase-Producing Coriolopsis gallica Strain T906: Mutation Breeding, Strain Characterization, and Features of the Extracellular Laccases.
Commercial application of laccase is often hampered by insufficient enzyme stocks, with very low yields obtained from natural sources. This study aimed to improve laccase production by mutation of a Coriolopsis gallica strain and to determine the biological properties of the mutant. The high-yield laccase strain C. gallica TCK was treated with N-methyl-N-nitro-N-nitrosoguanidine and ultraviolet light. Among the mutants isolated, T906 was found to be a high-production strain of laccases. The mutant strain T906 was stabilized via dozens of passages, and the selected ones were further processed for optimization of metallic ion, inducers, and nutritional requirements, which resulted in the optimized liquid fermentation medium MF9. The incubation temperature and pH were optimized to be 30°C and 4.5, respectively. The mutant strain T906 showed 3-times higher laccase activity than the original strain TCK under optimized conditions, and the maximum laccase production (303 U/ml) was accomplished after 13 days. The extracellular laccase isoenzyme 1 was purified and characterized from the two strains, respectively, and their cDNA sequence was determined. Of note, the laccase isoenzyme 1 transcription levels were overtly increased in T906 mycelia compared with values obtained for strain TCK. These findings provide a basis for C. gallica modification for the production of high laccase amounts.
Institute of New Energy and New Materials, South China Agriculture University, Guangzhou 510642, P.R. China.|Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture, Guangzhou 510642, P.R. China.
Xiaoli
X
Xu
Institute of New Energy and New Materials, South China Agriculture University, Guangzhou 510642, P.R. China.
Lei
L
Feng
Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture, Guangzhou 510642, P.R. China.
Zhenya
Z
Han
Institute of New Energy and New Materials, South China Agriculture University, Guangzhou 510642, P.R. China.
Sishi
S
Luo
Key Laboratory of Biomass Energy of Guangdong Regular Higher Education Institutions, Guangzhou 510642, P.R. China.
Ai'min
A
Wu
Institute of New Energy and New Materials, South China Agriculture University, Guangzhou 510642, P.R. China.|Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture, Guangzhou 510642, P.R. China.
Jun
J
Xie
D055453:Coriolaceae / Q000201:enzymology* / Q000235:genetics*; D005110:Extracellular Space / Q000201:enzymology; D005656:Fungal Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D042845:Laccase / Q000032:analysis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D015202:Protein Engineering; D013696:Temperature
D005656:Fungal Proteins; D042845:Laccase
Coriolopsis gallica; laccase; mutagenesis