真菌漆酶活性与石油降解率的关系

Study on the Relationship between Laccase Activity and Crude-oil Degradation Rate of the Fungus

[目的]研究真菌漆酶活性与原油降解率之间的关系。[方法]对4株石油降解真菌在液体培养基中的漆酶活性、菌丝干重、原油降解率及石油组分进行了测定,分析了漆酶在原油降解过程中的作用,探讨真菌漆酶活性与原油降解率之间的关系。[结果]在基础液体培养基中,不同菌株的菌丝干重和漆酶活性差异较大,培养7 d后菌株DQ7(Aspergillus sp.)的菌丝干重最大,培养15 d后菌株D2(Actinomucor sp.)的漆酶活性最高;相关分析表明菌株的菌丝干重与漆酶活性相关不显著。在原油液体培养基中,培养30 d后菌株D2对原油的降解率和漆酶活性最大,分别为42.41%和48.26 IU/ml;菌株DQ5(Fusarium sp.)和DQ7对原油的降解率及漆酶活性最低;不同菌株对石油组分降解情况不同;仅菌株D2的漆酶活性与原油的降解速率相关性较大(r=0.869),但没有达到显著性水平。[结论]漆酶是影响真菌降解原油效率的重要因素之一,能够提高真菌对原油的降解速率和降解率,但真菌对原油的降解率还与菌株的种类及其生长特性等因素有关。

[ Objective] The research aimed to study the relationship between laccase activity and crude-oil degradation rate of the fungus. [ Method ] The laccase activity, dry mycelial weight （DMW）, crude-oil degradation rate （CODR）and petroleum components of four petroleum degradation fungus were measured in the liquid medium, the function of laccase was studied in crude oil degradation process, and the relation-ship between laccase activity and CODR of the fungus were explored. [ Result] In the liquid medium with the sucrose, there were significant differences of DMW and the laccase activity among the fungi strains. DMW of DQ7（AspergiUus sp. ）was the heaviest after 7 d, and the laccase activity of D2（Actinomucor sp. ） was the highest after 15d, and correlation analysis showed that there was no significant correlation between DMW and the laccase activity. After 30d cultivation in the liquid medium with the crude oil, CODR and the laccase activity of D2 were the highest, they were 42.41% and 48.26 IU/ml. CODR of DQ5 （ Fusarium sp. ） and DQ7 were the lowest. The results showed that different strains could degrade different components of petroleum hydrocarbons by GC-MS （Gas Chromatography-Mass Spectrometry） analysis. A positive relationship between CODR and the laccase activity of D2 was observed（ r = 0. 869）, but it was not significant. [ Conclusion ] The laccase is important factor affecting the oil degradation, it can increase the oil degradation rate of the fungus, but the oil degradation rate is also related with fungi strains, the growth characteristics of the fungus.