Abstract
P. osreatus belongs to a group of basidiomycetes, degrading
preferentially the lignin moiety in woody tissues. A system
enabling the conduction of solid state fermentation in chemically
defined medium using inert solid support was developed. Under
these conditions we could study fungal growth and activities in the
absence of manganese. Mn amendments were found to enhance
preferential lignin degradation by P. osreatus as shown by 14Clignin mineralization versus 14C-Cellulose mineralization as well
as the production of Mn-peroxidase. Plant extractives of peeled
cotton branches were also found to enhance lignin degradation by
the fungus. Cotton stalks amended with MnSO4 were shown to
loose 56% of their lignin fraction. Thus showing the potential of Pleurotus in biopulping of non-woody material. The role of Mn(III) in lignin degradation is studied using EPR spectroscopy
and spin-traps. It was shown that Mn(III) cart lead to the formation
of reactive peroxy radicals atler one-electron abstraction from
keto-acids. This is supported by the obligatory need for oxygen in
the reaction. These radicals, can serve as diffusible oxidants. A
complete system, performing the first step of ligninolysis could
then be the production of Peroxy-radicals in the reaction of Mn(III)
and plant extractives in the presence of oxygen.
preferentially the lignin moiety in woody tissues. A system
enabling the conduction of solid state fermentation in chemically
defined medium using inert solid support was developed. Under
these conditions we could study fungal growth and activities in the
absence of manganese. Mn amendments were found to enhance
preferential lignin degradation by P. osreatus as shown by 14Clignin mineralization versus 14C-Cellulose mineralization as well
as the production of Mn-peroxidase. Plant extractives of peeled
cotton branches were also found to enhance lignin degradation by
the fungus. Cotton stalks amended with MnSO4 were shown to
loose 56% of their lignin fraction. Thus showing the potential of Pleurotus in biopulping of non-woody material. The role of Mn(III) in lignin degradation is studied using EPR spectroscopy
and spin-traps. It was shown that Mn(III) cart lead to the formation
of reactive peroxy radicals atler one-electron abstraction from
keto-acids. This is supported by the obligatory need for oxygen in
the reaction. These radicals, can serve as diffusible oxidants. A
complete system, performing the first step of ligninolysis could
then be the production of Peroxy-radicals in the reaction of Mn(III)
and plant extractives in the presence of oxygen.
| Original language | American English |
|---|---|
| Pages (from-to) | 29-33 |
| Number of pages | 5 |
| Journal | 1997 Biological Sciences Symposium |
| State | Published - 17 Oct 1997 |