Production of a novel laccase from Paraphoma Sp

Abstract

By using a laccase-secretion indicator for screening laccase-producing microorganisms, a novel laccase-producing strain was isolated and identified as Paraphoma sp. strain GZS18, it produced increased laccase and mycelia at 34 °C. Further investigations showed that the production of laccase by Paraphoma sp. GZS18 was greatly enhanced by less toxic inducers copper sulphate and methyl orange. Copper sulphate and methyl orange were added into the cultivation medium at 12 and 60 h, respectively, and the maximum laccase production was obtained. Through Plackett–Burman design and response surface methodology, we obtained the optimum production conditions as follows: methyl orange, 39.90 μM; addition time of copper sulphate, 11.95 h; addition time of methyl orange, 51.40 h. Under the above conditions, the experimental value of laccase production was 12,250.76 U/L. The extracellular laccase from Paraphoma sp. GZS18 was purified to homogeneity, which showed a molecular mass of 75 kDa. N-terminal amino acid sequences was AX^aVSVASREMT.

Keywords:

• Paraphoma sp. GZS18
• laccase
• inducers
• methyl orange

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by the Science technology Program of traditional Chinese medicine and minority medicine in Guizhou Province of traditional Chinese medicine Administration [No. QZYY-2014-028]; the Doctor Foundation of Binzhou University [No. 2016Y02 and 2016Y17]; the Natural Science Foundation of Shandong Province [No. ZR2016CL01 and ZR2016BL16]; a project of Shandong Province Higher Educational Science and Technology Program [No. J17KA120]; the Research Project of the University-level teaching Reform of Binzhou University in 2017 [No. BYJYYB201736]; and the School-enterprise Co-construction Course Project of Binzhou University in 2017 [No. BYXQGJ201706].