Lecture 6: Biotechnology and Antifungals Flashcards
what are ectomycorrhizae important for?
coniferous forests as saprotrophs and for mineral weathering
where are ericoid mycorrhizae found?
peat bogs, moorlands, heathlands
why are ericoid mycorrhizae suited to those environments?
- low nutrient accessibility
- low pH
- high C:N ratio
- heavy metal toxicity
what benefit does ericoid mycorrhizae have?
enables plants to sustain environmental stresses
what are orchidaceous mycorrhizae?
belonging to basidiomycetes, they transport carbon via the plasmamembrane of living peletons OR by phagocytosis of collapsed fungal endophytes
what are monotropid mycorrhizae?
connect together different plants so that phosphorous can be transported
what does leaf-litter decomposition create?
the ideal conditions for the secondary sucession
what 3 types of cellulase break down wood?
endoglucanase: attacks cellulose at random, produces glucose, cellobiose and cellotriose
exoglucanase: attacks from non-reducing end of cellulose making cellobiose
cellobiase: hydrolyses cellobiose
what is produced when lignin is broken down by fungal enzymes?
lignin peroxidase, manganese peroxidase and laccase
what does the combined break down of cellulose and lignin produce?
white rot
what causes brown rot?
ONLY cellulose break down since lignin is left behind
what food is mycoprotein used in?
quorn
what antifungal drugs target polyenes and how?
Amphotericin B and Nystatin since they extract ergosterol from the membrane disrupting its function
what antifungal drugs target azoles and how?
imidazoles, triazoles, thiazoles that inhibit conversion of lanosterol to ergosterol by inhibiting lanosterol 14a-demthylase
what antifungal drugs target allylamines and how?
terbinafine, naftifine and thiocarbamate tolnaftate that blocks the conversion of squalene to lanosterol
what antifungal drugs target echinocandins and how?
caspofungin, micafungin, anidulafungin that inhibit the synthesis of B-glucan
what antifungal drugs target flucytosines and how?
interferes with RNA synthesis and inhibits fungal DNA synthesis
what are the 4 methods of antifungal susceptibility testing?
- minimum inhibitory concentration (MIC)
- minimum fungicidal concentration (MFC)
- clinical breakpoints
- CSLI, EUCAST, and FDA
