Common misconceptions in medical mycology

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Transcript Common misconceptions in medical mycology

Evaluation of novel wood-rotting polypores
and corticioid fungi for the decay and
biopulping of Norway spruce (Picea abies)
wood
Hakala et al 2004
EnzMicrobTechnol 34,255-63
Kerry Sproule, presenter
Wood is a high calorie carbon source,
composed of
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cell walls  interpenetrating matrix of cellulose and
hemicelluloses
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lignin  generic name for complex aromatic polymers
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cellulose  homopolymer of glucose
hemicellulose  heteropolymer of a mixture of sugars
product of free-radical polymerization
major component of vascular tissues
together with hemicellulose, it fills the spaces between
cellulose fibrils, coating the
lignin physically protects the polysaccharides from
attack by cellulases and hemicellulases
White vs brown rot
White vs Brown Rotters
Cellulose sparing
 Oxidases
 Intolerant of low pH
 Tolerant of high pH
Lignin sparing
 No Oxidases
 Tolerant of low pH
 Intolerant of high pH
Decomposition, recycling, spoilage
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Lignin degradation
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angiosperm
Peroxidases
Lignases
Laccases
Chemical attack on polymer
(peroxidases) followed by
specific attack (lignases, laccases)
gymnosperm
Laccase
http://lioroux.free.fr/
Multicopper
oxidases
"Our number one water quality problem in the
National Forests is roads.“
United States Under Secretary of Agriculture Jim Lyons, 2000
For every km of
paved road in
Washington State, >
7 km of unpaved
roads
Estimated cost of
decommissioning:
$6k - $180k per km
This and subsequent
Myco-remediation
images from
Fungi Perfecti
www.fungi.com
Adding grass seed to logging roads
doesn’t work efficiently
Value of mycoremediation
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Sediment containment
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Moisture enhancement
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reduction of diesel, oil, herbicides, pesticides, & other pollutants
Reduction/elimination of damaging downstream microorganisms
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re-establishing native mycoflora (mycorrhizae & saprophytic, soil building)
Reduction/elimination of Hydrocarbon contamination
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restoration of aquifer function (allowing subsurface sheet flows of water)
re-moistening of arid landscapes
Habitat recovery & Enhancement
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reduction of siltation/erosion into streams  spawning grounds & fisheries
mycofiltration of coliform bacterial, E. coli, Pfisteria, & protozoa
Temperature reduction
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cooling of water flowing into streams  fisheries & marine systems
Mycoremediation
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Minimal disturbance
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Subsurface penetration by mycelium
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accessible educational showcase for habitat restoration
Bad bugs/Good bugs*
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roads transformed into nature trails multi-use access
Educational showcase
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Subsurface growth of mycelium  mineral transport, aeration, without siltation
flow
Aesthetic enhancement
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low impact on existing & adjacent ecosystems
breeding ground for grubs  fish food chain
mycopesticidal barriers for wood boring beetles & disease insects
breeding grounds for beneficial bugs
Investment Protection
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road subsurface can be re-used in future
Mycoremediation of logging roads – Fungi Perfecti
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‘Hog-fuel' (bark and wood
chips) onto logging roads
inoculate debris with mycelia
of a mosaic of keystone
native fungal species
Fungus+wood chips prevent
silt-flow through the natural
filtration properties of
mycelial networks
renew topsoils, spurring the
growth of native flora
8-30 cm straw
+ woodchips
+ Pleurotus ostreatus
inoculum
Pleurotus ostreatus is a native
saprophytic species, easy to
amplify in culture
4 weeks later…
Pleurotus ostreatus
3 years later
- abundant mycelium from
mixed species
- new soil formation
After “mycoremediation”
4 years, 2-5cm soil
5+ years
Using fungi for nutritional
improvement
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plant proteins are often relatively low in essential
amino acids like lysine which are relatively
enriched in fungi
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fungal enrichment improves flavour, texture,
nutritional value
uses naturally occurring fungi, or those inoculated
deliberately
Modified forage
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2.1 x 1012 kg per year – cereal straw, sugarcane
and sugar beet residue – contains nutrients,
primarily as cellulose and lignins
low digestibility (40-60%) even for herbivores
generally subsistence nutrition, but leads to low
growth rates, and need for feed supplements
Tempeh – traditional
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Used for food and feed
Modifying agricultural waste  materials that do
not have economic value by direct use, or for
conversion by animals into valuable products
Undigestible carbohydrates are wrapped in large
leaves (banana) and left 1-2 d for solid
fermentation
Tempeh – solid fermentation
Tempeh
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soybeans are boiled and dehulled
Rhizopus oligosporus grows < 24 h, creating
a solid cake of hyphae/beans
Traditionally, tempeh is stored wrapped in
banana leaves, and eaten soon
growth is halted (cooking, freezing) before
sporulation begins
Tempeh – commercial
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Soybeans are made more digestible by lipases
and proteases secreted by Rhizopus,as well as
fungal components
Fungi provide “complete” protein