Studies On Phanerochaete Chrysosporium And Its Laccases As Well As Their Degradation To Pentachlorophenol

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.