生态环境学报Issue(2)：329-335,7.DOI:10.16258/j.cnki.1674-5906.2015.02.023
外生菌根真菌Xerocomuschrysenteron产漆酶能力及其对外加DDT和重金属的响应
Efficiency of Laccase Secretion by the Ectomycorrhizal Fungus Xerocomus chrysenteron and Its Responses to the Addition of DDT and Heavy Metals
摘要
Abstract
The efficiency of laccase secretion by the ectomycorrhizal fungus Xerocomus chrysenteron and its responses to medium carbon: nitrogen ratio and the addition of DDT and heavy metals were studied in the modified Kottke medium. Additionally, the mechanisms underlying the observed responses were explored. Laccase secreted by X. chrysenteron showed high affinity for degrading 2,2'-azino-bis(3-ethylthiazoline-6-sulfonic acid) (ABTS) with a half saturation constant (Km) of 0.038 mmol·L-1. Laccase activity was found to be highest at the stationary phase and reached 118 U·L-1 after 63 d of culture. The maximum laccase activity could reach 157 U·L-1 in both the static culture and the shaking culture. Elevating medium carbon:nitrogen ratio to 20 led to higher laccase activity. Adding 1 mg·L-1 and 5 mg·L-1 of DDT increased the laccase production by 0.5 and 1 fold after 63 d of culture, respectively. Adding 1 mmol·L-1 of different heavy metals showed differential effects on laccase production. Cu and Cd increased the laccase production by 2.6 and 0.3 fold after 63 d of culture, respectively;Zn and Hg inhibited the laccase production;Mn showed no significant effects. Adding 5 mmol·L-1 of Cu had no significant effects on the laccase production, while 5 mmol·L-1 of Cd decreased the laccase production. These effects of heavy metals may be explained by laccase induction (or inhibition) and decreases in mycelium production caused by the metals. This study demonstrated that high carbon: nitrogen ratio and the addition of suitable concentrations of DDT, Cu and Cd could promote the laccase production by X. chrysenteron, suggesting the potential application of this fungus for degrading POPs in multiple-contaminant environment.关键词
外生菌根真菌/Xerocomus chrysenteron/漆酶/DDT/重金属Key words
ectomycorrhizal fungi/Xerocomus chrysenteron/laccase/DDT/heavy metals分类
资源环境引用本文复制引用
赵曦,黄艺,李娟..外生菌根真菌Xerocomuschrysenteron产漆酶能力及其对外加DDT和重金属的响应[J].生态环境学报,2015,(2):329-335,7.基金项目
国家自然科学基金项目 （）
