Fig. 5

Activity comparation of the recombinant LPMOs (A) and purification results of the recombinant AlLPMO13 (B). A The activity of each enzyme was determined according to the method descripting in the “Enzyme activity assay of AA13 family LPMOs by AmplexTM Ultra Red method” section. The activity of MtLPMO was set as the control (100%). The relative activity of each new screened LPMO was calculated to the percentage against to that of the control. Data of the activities are presented as mean ± SD (n = 3). An analysis of variance (ANOVA) and a comparison of the means were conducted with the multiple range comparison LSD test. A probability value of p < 0.05 was considered as significant. “****” means p < 0.001. B lane M: molecular weight of marker standard, lane 1: intracellular soluble proteins of the recombinant strain expressing AlLPMO13, lane 2–4: the purified AlLPMO13 with affinity chromatography