Fungi Yeast and Warm Fuzzies 8

균류의 특징 Ecologically important decomposers( 분해자 ) Break down complex organic molecules into simple molecules that can be used by other organisms 균류는 진핵세포 미생물이다. 균사 (hypha) 형태로 자라며 균사체 (mycelium) 를 형성한다. 엽록소가 없다. 유성생식과 무성생식으로 번식한다. 키틴 (chitin) 성분의 세포벽으로 된 분지된 섬유상 구조. 포자를 생성한다.

Survival during a Bleak Era Fungi may have filled niche during dinosaur extinction Plants did not survive the extinction, either Fungi survived by feeding off decaying animal and plant matter Figure 8.1: A)TEM of a yeast cell showing typical eukaryotic features; B) Two molds, one wrapped around the other, in a parasitic relationship (Bar = 10 μm); C) A mold growing on a grapefruit Reproduced by permission of the National Research Council of Canada; E.M. Peterson, R.J. Hawlay, and R.A. Calerone. The Canadian Journal of Microbiology, 22(10): Reprinted with permission from the American Society for Microbiology (I Chet, Y Elad and R Barak; J. Bacteriol, 1983 June; 154(3): ) Courtesy of Scott Bauer/USDA ARS

Classification, Structure, and Growth of Fungi Yeasts Molds Hypha Mycelium Mycology Mycosis Figure 8.2: A false-colored SEM of Cladosporium cladosporioides, one of the most common fungi isolated from air samples (x300) © Dr. Dennis Kunkel/Visuals Unlimited

Classification, Structure, and Growth of Fungi Structure of fungi –Nuclei –Many fungi form spores –No chlorophyll –Reproduce sexually and asexually –Cell walls contain chitin –Septa

Classification, Structure, and Growth of Fungi Nutrition in fungi –Almost all heterotrophic( 종속영양 ) Digestive enzymes secreted outside cell Simple breakdown products absorbed by cell –Cellulase –Ligninase –Glucose stored as glycogen –Some fungi exist as saprobes( 부생생물 ) –Some fungi exist as parasites( 기생생물 )

Classification, Structure, and Growth of Fungi Nutrition in fungi –Usually exist in acidic conditions –Therefore fungi can grow in familiar acidic foods Sour cream Yogurt Citrus fruit Most vegetables Bread Cheese –Favorable contamination Cheese (e.g., blue cheese and Penicillium requeforti)

Classification, Structure, and Growth of Fungi Figure 8.4: Products of Fungal Activity © Photodisc Courtesy of Scott Bauer/USDA ARS

Classification, Structure, and Growth of Fungi Reproduction in fungi –Sexual reproduction Arthospores( 분절포자 ) Chlamydospores( 후막포자 ) Cell fusion and and spore formation Haploid parent cells Diploid progeny, called zygote( 접합자 ) Meiosis of zygote creates haploid spores Spores are environmentally resistant, like bacterial spores Spores germinate to form new haploid organism Results in fewer spores, but more genetic diversity

Classification, Structure, and Growth of Fungi: Sexual Reproduction in Fungi Figure 8.5: Sexual Reproduction in Fungi Reproduced by permission of the National Research Council of Canada; O'Donnell, K.L., Ellis, J.J, Hesseltine, C.W. and Hooper, G.R. The Canadian Journal of Botany, 55(6):

Classification, Structure, and Growth of Fungi Reproduction in fungi –Asexual reproduction Spores –Formed on sporangium or conidiophore –Conidium( 분생포자 ) –Environmentally stable, like bacterial spores –Produces extremely large number of spores –All spores are genetically identical to parent cell

진균류의 종류 Chytridiomycota( 병꼴균문 ) : 가근 (rhizoids) 으로 영양분 기부에 부착. 운동성배우자의 융합에 의한 유성번식. Uniflagellate zoospores 형성 Zygomycota( 접합균문 ) : 무격벽 (aseptate) 균사형성. 유성생식에 의하여 zygospores( 접합포자 ) 형성. Ascomycota( 자낭균문 ) : 격벽 (septa) 이 있는 균사형성. 유성생식에 의하여 자낭포자 (ascospores) 를 함유하는 자낭 (ascus) 형성. Deuteromycota( 불완전균문 ) : 유성생식이 알려지지 않음. 무성생식에 의하여 분생포자 (conidia) 형성. Basidiomycota( 담자균문 ) : 유성생식에 의하여 담자포자 (basidiospores) 를 담자기 (basidium) 위에 형성함. 버섯류

Divisions of Fungi Zygomycota( 접합균문 ) –Called zygomycetes –Zygospores( 접합포자 ) Thick-walled, environmentally resistant spores Develop from fusion of two sexually opposite cells –Rhizopus stolonifer: common black bread mold –Fermentation of rice into sake by one Rhizopus species –Cortisone production by different Rhizopus species

Divisions of Fungi Asomycota( 자낭균문 ) –30,000 species of ascomycetes (a.k.a., sac fungi) –Asci( 자낭 ) –Most are filamentous –Some are yeasts –Septa allow mixing of adjacent cells’ cytoplasms –Ascospores( 자낭포자 ) –Ascocarps( 자낭과 ) Figure 8.6: Ascospores (A) and conidia (B) of the fungus Aspergillus quadrilineatus Reprinted with permission from the American Society for Microbiology (Polacheck I, Nagler A, Okon E, Darkos P, Plaskowitz J and Kwon-Chung, K.J.; J. Clin Microbiol, 1992 December; 30(12): ) Photo courtesy of Doctor K.J. Kwon-Chung

Divisions of Fungi Ascomycota –Various Penicillium species Antibiotics –Penicillin –Ampicillin –Amoxicillin –Methicillin Blue cheese –Various Aspergillus species Contaminate house dust Cause allergies, respiratory illness Aflatoxins Production of food products –Citric acid –Soy sauce –Vinegar

Divisions of Fungi Ascomycota –Claviceps purpurae( 맥각균 ) Infects rye Ingestion results in ergot disease in humans Potential headache cure, in low doses Potential bioterrorism weapon

Divisions of Fungi Basidiomycota( 담자균문 ) –Includes mushrooms –Called basidiomycetes –Basidiocarp( 담자과 ) –Dikaryotic stage –Basidiospores( 담자포자 ) –Basidium( 담자기 )

Divisions of Fungi: Life Cycle of Basidiomycota Figure 8.7: The life cycle of a typical basidiomycete

Division Basidiomycota( 담자균문 ) Class Urediniomycetes ( 녹병균강 ): Order Uredinales( 녹병균목 ) : 양치식물, 나자식물 및 피자식물에 기생해서 녹병을 일으키는 녹병균 (rust) 류. 강한 숙주특이성을 갖는다. Class Ustilagomycetes( 깜부기병균강 ) : Order Ustilaginales( 깜부기균 목 ) : 깜부기병균류 (smut fungi) 와 담자균 효모류를 포함한다. Class Basidiomycetes( 담자균강 ) : 목이버섯 목 (Auriculariales) 흰목이 목 (Tremellales), 떡병균 목 (Exobasidiales) 붉은목이 목 (Decryomycetales) 민주름버섯 목 (Aphyllophorales) 주름버섯 목 (Agaricales) 알버섯 목 (Hymenogastrales) 어리알버섯 목 (Sclerodermatales) 찻잔버섯 목 (Nidulariales) 말불버섯 목 (Lycoperdales), 말뚝버섯 목 (Phallales)

Divisions of Fungi Deuteromycota( 불완전균문 ) –About 25,000 species –No currently identified form of sexual reproduction –Also known as deuteromycetes or Fungi Imperfecti –Conidia( 분생자 ) –Many human pathogens Dermatophytes of athlete’s foot – Pseudomassaria Chemical that mimics effects of insulin

불완전균문 (Deuteromycota) 예 : Alternaria, Aspergillus, Aureobasidium, Clasdosporium, Geotrichum, Penicillium, Humicola 주요특징 ; 유성생식이 없거나 드믈거나, 알려져 있지 않다. 출아불완전균류 (blastomycetes) ; 효모류 총생균류 (hyphomycetes) ; 단순하고 균사와 유사한 분생포자경을 갖는다. 유각균류 (coelomycetes) ;

Beneficial and Harmful Fungi Yeasts –Saccharomyces Ascomycota Single cells Saccharomyces cerevisiae –Baking –Accumulation of CO 2 during Krebs cycle makes dough rise –Enzymes break down gluten, giving spongy texture Saccharomyces ellipsoideus –Brewing –Fermentation results in production of CO 2 and ethanol –Different starting materials give rise to wines and beers Fig. 8.1a 효모의 전자현미경사진. Reproduced by permission of the National Research Council of Canada; E.M. Peterson, R.J. Hawlay, and R.A. Calerone. The Canadian Journal of Microbiology, 22(10):

Beneficial and Harmful Fungi Yeasts –Tools for biotechnology –Tools for human genome project

Beneficial and Harmful Fungi Lichens( 지의류 ) –Association between fungus and photosynthetic partner –Approximately 15,000 lichen species –Almost all have ascomycetes as the fungus –Most frequent photosynthetic partners Trebouxia (green algae) Trentephila (green algae) Nostoc (cyanobacterium) Fig 8.10 lichens © Popovici loan/ShutterStock, Inc.

Beneficial and Harmful Fungi Lichens –Grow in a diversity of environments Arid deserts( 건조한 사막 ) Arctic zones( 북극지방 ) Bare soil Tree trunks Rocky areas –Photosynthetic partner provides sugar and carbohydrates –Fungal partner supplies protection and basic biochemical building blocks –Can survive in as little as 2% water –Very slow growth (less than 10 mm per year)

Beneficial and Harmful Fungi Mycorrhizae( 균근류 ) –Mutualistic fungi that live amongst roots of vascular plants( 유관식물 ) –Over 5,000 species –Plant provides photosynthetic products –Fungi provide more nutrients than plant can absorb through roots alone –Garden plants typically associate with zygomycetes

Beneficial and Harmful Fungi Fungi and human disease –Candida albicans Normal vaginal flora –Held in check by other acid- producing flora –Overuse of antibiotics, which may kill normal flora, leads to yeast infection (candidiasis) –Can be treated »Antifungal creams »Eating yogurt Normal oral flora –If immune depleted (e.g., AIDS), can infect mouth –Disease is called thrush –Treatment with oral antifungals Figure 8.11: An SEM of Candida albicans Reprinted with permission from the American Society for Microbiology (Balish, E., Balish, M.J., Salkowski, C.A., Lee, K.W., and Bartizal, K.F; Appli. Environ. Microbiol, 1984 May; 47(4): )

Beneficial and Harmful Fungi Fungi and human disease –Cryptococcus neoformans Infects lungs and meninges –Tinea diseases Skin infections –Athlete’s foot –Barber’s itch –Jock itch –Ringworm Fig. 8.12: C. neoformans Figure 8.13: Ringworm from Trichopyton tonsurans Reprinted with permission from the American Society for Microbiology (ASM News. December 1998, Vol. 64(12): ) Photo courtesy of Doctor Stuart Levitz, University of Massachusetts Medical Center. Reprinted with permission from the American Society for Microbiology (Dykstra, M.A., Friedman, L. and Murphy, J.W.; Infect. Immun May; 16(1): ) © Medical-on-Line/Alamy Images

Beneficial and Harmful Fungi Fungi and human disease –Coccidioides immitis Respiratory disease American Southwest May proceed to meningitis Sometimes called Valley Fever Potential bioterrorism weapon –Histoplasma capsulatum Found in bird droppings Respiratory illness –Blastomyces dermititidis Found in bird droppings Respiratory illness