Fungi & Yeast
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Transcript of Fungi & Yeast
Fungi
Eucaryotic, unicellular to multicellular, microscopicto macroscopic organisms, spore bearer withabsorptive nutrition and lacking chlorophyll
Distribution
• Terrestrial, fresh water and marine• Also in polar region
ImportanceBeneficial-• act as decomposer, degrade complex organic
compound• Carbon, nitrogen, phosphorous and others are
recycled• Making of bread, wine, beer• Preparation of cheeses, soy sauce and sufu• Production of organic acids- citric acid, gallic acid• Drugs- cortisone• Antibiotics- penicillin,
Beneficial
• Immunosuppressive drug- cyclosporin• Important research tool
Harmful effect-• Pathogenic for plants, animals• Over 5000 sp attack economically valuable crops,
garden plants and many wild plants• About 20 new human fungal pathogens are
documented each year
Structure
• Single cell ( yeast) to multi-cellular• Cell wall is having chitin• Thallus- vegetative structure• Thallus consists of long, branched, thread like
structure called hyphae• Collection of hyphae make mycelia• Collection of mycelia make thallus
Mycelium
Nutrition and metabolism• Most fungi are saprophytes• They grow in dark, moist habitat rich with organic
materials• Release hydrolytic enzymes to digest substrate• Chemoorganoheterotroph• Storage material-glycogen• Use glucose or maltose and nitrogenous
compounds to synthesize their own amino acidsand proteins
• They are usually aerobic except yeast(facultativeanaerobe)
• Obligatory anaerobes are found in rumen
Reproduction-asexual1. Transverse fission-
2. Budding-
Reproduction3.Arthrospore
4.sporangiospore
5.chlamydospore
6. Zoospore
7. conidiospore
Sexual reproduction
Zygospore
Ascospore
Ascocarp
Basidiospores
1
2
3
4
Classification
Sub class- UrediniomycetesMycelial or yeast form
5
Life cycle of Yeast
Ustiloginomycetes 6• Common corn pathogen, causes tumour in plants• Have specialized hyphae called appresorria for
penetrating host tissue• With the help of these tomours are formed and
fungi grow inside to produce spores calledteliospores
Glomeramycota 7• Ecologically important• Eg. Mycorrhizal fungi- association between fungi
and plants
Importance of Mycorrhiza
• Fungus help protect its host from stress• Delivers nutrients from soil• Fungus get carbohydrate from the plant
Microsporidia 8• Confusing taxonomy(curious fungi)• Considered as protist• Some are pathogens• Are obligatory parasite, infects insects, fish,
human (AIDS patients are the target)• Causes diarrhoea, pneumonia, encephalitis,
nephritis• Morphology of spore- unique
polaroplast
exospore
endospore
nucleus
Polar tube
Posterior vacuole