Laboratorio de Micología Experimental, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Buenos Aires, Argentina.
Mycologia. 2002 May-Jun;94(3):377-83.
Trametes trogii, a white rot basidiomycete involved in wood decay worldwide, produces several ligninolytic enzymes, laccase being the dominant one, with higher titers than those reported for most other white rot fungi studied up to date. The effect of copper on in vitro production of extracellular ligninolytic activities was studied. CuSO(4)·5H(2)O concentrations from 1.6 μM to 1.5 mM were tested in a synthetic medium with glucose 20 g/L and asparagine 3 g/L. The addition of copper (up to 1 mM) did not affect growth but strongly stimulated ligninolytic enzyme production; faster decolorization of the polymeric dye Poly R-478 was observed as well. Maximal production of manganese peroxidase, laccase, and glyoxal oxidase [1.28 U/mL, 93.8 U/mL (with a specific activity of 720 U/mg protein), and 0.46 U/mL respectively] was attained with 1 mM CuSO(4)·5H(2)O. However, higher copper concentrations inhibited growth and notably decreased manganese peroxidase production, although they did not affect laccase secretion. Laccase activity in the culture filtrate was maximal at 50 C and pH 3.4, and the enzyme was completely stable at pH 4.4 and above, and at 30 C for up to 5 d. Denaturing polyacrylamide gel electrophoresis of extracellular culture fluids showed two laccase activity bands (mol wt 38 and 60 kDa respectively). The pattern of isoenzyme production was not affected by medium composition but differed with culture age.
云芝，一种参与全球范围内木材腐朽的白腐担子菌，能够产生几种木质素降解酶，其中漆酶是主要的一种，其比迄今为止研究过的大多数其他白腐真菌的酶产量都高。研究了铜对体外产生细胞外木质素降解酶活性的影响。在含有 20 g/L 葡萄糖和 3 g/L 天冬酰胺的合成培养基中，测试了从 1.6 μM 到 1.5 mM 的 CuSO4·5H2O 浓度。铜的添加（最高达 1 mM）不影响生长，但强烈刺激木质素降解酶的产生；观察到聚合染料 Poly R-478 的更快脱色。在 1 mM CuSO4·5H2O 存在下，锰过氧化物酶、漆酶和乙二醛氧化酶的最大产量分别达到 1.28 U/mL、93.8 U/mL（比活为 720 U/mg 蛋白）和 0.46 U/mL。然而，较高的铜浓度抑制了生长，特别是降低了锰过氧化物酶的产量，尽管它们不影响漆酶的分泌。漆酶在培养滤液中的活性在 50°C 和 pH 3.4 时达到最大值，在 pH 4.4 及以上和 30°C 下可稳定 5 d 以上。细胞外培养液的变性聚丙烯酰胺凝胶电泳显示出两条漆酶活性带（分子量分别为 38 和 60 kDa）。同工酶的产生模式不受培养基组成的影响，但因培养年龄而异。
