【作者】 彭丹；

【导师】 曾光明；

【作者基本信息】 湖南大学 ， 环境科学与工程， 2008， 硕士

【摘要】 近几年,由于合成化合物造成的环境污染,如,有机氯化合物和石油烃已经引起了人们极大的关注。许多化学物质是有毒的,并且由此带来的风险分析显示,把大多数人暴露于低浓度的化学物质中可能会对健康产生不利影响。生物修复技术被用来处理这种环境污染。生物修复技术利用活的有机体,通常是细菌或真菌,从土壤和水环境中消除污染物,特别适用于原位处理。与土壤焚化和活性碳吸附水等传统技术相比,这种方法可能更具经济效益。黄孢原毛平革菌是被研究最广泛的一种白腐菌,它一直是许多生物降解研究的主要对象。主要研究热点是黄孢原毛平革菌分泌木质素降解酶系统降解木质素和木素聚合物的能力。这个降解酶系统主要系统主要包括三种过氧化物酶:木质素过氧化物酶（LiP） ,锰过氧化物酶（MnP） ,和漆酶（Lac）。生物降解是降解氯酚污染物的一条重要的转化途径,白腐真菌（特别是黄孢原毛平革菌）是一种高效的生物降解菌种,应用白腐真菌生物技术降解具有毒性和抗降解性的氯酚具有重要意义。本文以黄孢原毛平革菌和黄孢原毛平革菌漆酶为主线,从漆酶的生产培养、漆酶的分离纯化到漆酶和黄孢原毛平革菌对五氯酚污染物的降解等方面进行了较为系统的研究和分析并取得了较好的研究结果。对黄孢原毛平革菌（BKMF-1767）利用香蕉皮和玉米棒为发酵底物产胞外漆酶进行了研究。当香蕉皮与玉米棒混合比例为1:2、诱导剂为0.4mM CuSO₄时,能获得最高漆酶活12.68U/g。并利用固态发酵所获得的粗漆酶液,进行了降解五氯酚的试验。在没有氧化还原介体时粗漆酶液能降解PCP,粗酶液中加入5mM氧化还原介体（ABTS）能获得更高的降解率,反应6小时分别为37.8%和97%。将粗漆酶液用（NH₄）₂SO₄盐析纯化,用提纯后漆酶降解PCP,6小时后降解率为81.8%。黄孢原毛平革菌在固态发酵体系产真菌漆酶是一个既经济又有效的产酶途径,能获得高漆酶活和高五氯酚的降解率。更多还原

【Abstract】 In recent years,environmental pollution by synthetic chemicals such as organochlorine compounds and petroleum hydrocarbons has caused great concern.Some chemicals are toxic,and risk analyses suggest that exposure of a large population to chemicals at low concentrations may adversely affect the health of a significant number of individuals.Bioremediation technology is applicable to the treatment of such environmental pollution. Bioremediation involves the use of living organisms,usually bacteria or fungi, to remove pollutants from soil and water,preferably on-site.This approach is potentially more cost-effective than such traditional techniques as soil incineration and carbon filtration of water.The basidiomycete Phanerochaete chrysosporium is the most extensively characterized white rot fungus.It has been the subject of extensive investigation and many biodegradation studies. The primary interest stems from the ability of P. chrysosporium to degrade lignin and wood polymer by lignin degrading enzyme systems.The major system components of this organism are members of three families of extracellular glycosylated heme peroxidases: lignin peroxidase（LiP）,manganese peroxidase （MnP）, and Laccase （Lac）. Biodegradation is an important way for chlorophenol degradation, and white-rot fungus （especially the Phanerochaete chrysosporium） is an effective strain for biodegradation, so it is significant to degrade chlorophenol by using white-rot fungus, because chlorophenol is toxic and antidegradation.A systematic research of Phanerochaete chrysosporium and P.chrysosporium laccases has been made in the article,including fermental condition for laccase production by P.chrysosporium,isolation,purification from P.chrysosporium, Phanerochaete chrysosporium and P.chrysosporium laccase’s degradation to pentachlorophenol（PCP）.A plenty of good results have been made.This paper investigated the potential of banana skin and corn cob as a support-substrate for the production of extracellular laccase by the white-rot fungus Phanerochaete chrysosporium BKMF-1767. Laccase showed a maximum activity of 12.68U/g when the proportion of banana skin and corn cob is 1:2 and the inducer is 0.4mM CuSO4. In addition, crude laccase enzyme shows degradation activity to pentachlorophenol （PCP） without redox mediator or with the redox mediator （ABTS） at a concentration of 5 mM, and the degradation rates of PCP were 37.8% and 97% respectively after 6 h. The crude Laccase was purified by treatment of （NH₄）₂SO₄, and the purified Laccase could make the degradation rate of PCP to 81.8% within 6 h. High laccase activity and efficient degradation of PCP suggest that it is an economical and effective way to produce laccase by Phanerochaete chrysosporium in solid-state fermentation system.更多还原