Degradation of chlorophenols by Phanerochaete chrysosporium : effect of 3,4-dichlorophenol on extracellular peroxidase activities

Abstract

Extracellular peroxidases play an important role in the degradation of chlorophenols by Phanerochaete chrysosporium. Depending on the moment of 3,4-dichlorophenol addition, the production of lignin peroxidase and manganese peroxidase in C-limited agitated cultures was affected in opposite ways. In cultures that received 3,4-dichlorophenol at the time of inoculation, fungal growth was reduced and peroxidases were not produced, whereas peroxidase activities were stabilized after 3,4-dichlorophenol addition to pregrown cultures. Further investigation revealed that mRNA encoding lignin peroxidase was not produced in cultures started with 3,4-dichlorophenol, suggesting that the onset of secondary metabolism was affected. In addition, the stabilization of lignin peroxidase activity was not the result of an activation of lignin peroxidase gene transcription, as shown by Northern blot experiments, but likely due to the inhibition of peroxidase degradation by extracellular proteases.

Lactoferrin (LF): a natural antimicrobial protein

“…The protective effect was confirmed as a greater increase in weight and lesser prevalence of illness. [123] Duran, Deschler, Precigou and Goulas [124] expounded that the dietary supplements of bovine lactoferrin has antibacterial, antiviral and antioxidant properties and enhance the immune system response. One capsule of control was given to eight healthy males of 30 to 55 years for 7 days.…”

Estudo da expressão de genes regulada por ferro em fungos ligninoliticos

“…Entre os fungos de degradação branca, a espécie Phanerochaete chrysosporium é a mais extensivamente estudada devido a sua eficiência em degradar lignina (Yadav & Loper, 2000;Mester et al, 2001;Hirai et al, 2002) e uma variedade de poluentes ambientais (Cameron et al, 2000;Duran et al 2002;Bending et al, 2002) durante o metabolismo secundário (Cameron et al, 2000). Desta forma, o fungo P. chrysosporium é considerado um organismo modelo para o estudos destes processos (Lamar et al, 1995;Schick Zapanta & Tien, 1997;Scheel et al, 2000).…”