芳香族化合物对斑玉蕈菌丝生物量、漆酶活性及其转录水平的影响

Effects of aromatic compounds on biomass, laccase activities and transcript levels of Hypsizygus marmoreus

芳香族化合物适当时间适当浓度添加到培养基中,可提高真菌漆酶活性,有助于增强其对木质纤维素的利用效率。为了增强斑玉蕈漆酶活性,本文研究了8种芳香族化合物对其酶活的影响及其与菌丝生物量的相关性。研究发现在无诱导物条件下,斑玉蕈漆酶活性和菌丝生物量相关系数r为0.9956,说明它们呈正相关,但是整个培养过程漆酶活性相对较低;供试的芳香族化合物对漆酶活性都有不同程度的诱导作用,其中添加0.1mmol/L的愈创木酚对斑玉蕈漆酶活性诱导作用最大,达到3倍以上,同时提高了斑玉蕈菌丝生长速度和菌丝生物量;而随着添加时间的延长,部分化合物对漆酶活性和菌丝生物量都产生不同程度的抑制作用,这可能因为化合物对菌丝毒性的延长导致菌丝生长变慢或死亡;进一步研究发现,斑玉蕈3个漆酶同工酶基因lcc2、lcc3和lcc4在诱导剂愈创木酚的影响下转录水平都不同程度地上调。研究结果表明诱导漆酶活性可以提高斑玉蕈菌丝生长速度和生物量,暗示可能通过提高漆酶活性的方法,提高斑玉蕈的培养基利用效率。

Adding aromatic compounds in the culture medium could increase laccase activity and the utilization efficiency of lignin and cellulose in the suitable time and concentration. In order to increase the laccase activity in Hypsizygus marmoreus, the effect of eight aromatic compounds on the laccase activity and the relationship between the laccase activity and mycelial biomass were studied. It was found that the r value between laccase activity and mycelial biomass was 0.9956, indicating that they had positive correlation, but the laccase activity was relative low in the culture process. Most of these chemicals induced the laccase activity in different levels, reaching three times higher than the control by using 0.1mmol/L guaiacol, and these chemicals increased mycelial growth and biomass of H. marmoreus at the same time. However, some chemicals inhibited the laccase activity and mycelial biomass at different levels with the prolongation of culture period, probably resulting from the toxicity of these chemicals. It was also found that the transcription of three laccase genes were up-regulated at different levels under the affection of guaiacol in H. marmoreus. This study indicated that increasing laccase activity could stimulate the mycelial growth and biomass of H. marmoreus, and enhance the medium utilization efficiency.