Survey of eucaryotic microbes Fungi Algae Protozoa Parasitic helminths (worms)

Kingdom Fungi 100,000 species divided into 2 groups: macroscopic fungi (mushrooms, puffballs, gill fungi) microscopic fungi (molds, yeasts) majority are unicellular or colonial, a few have cellular specialization

Roles of fungi decomposers of dead plants and animals sources of antibiotics used in making foods & in genetic studies adverse impact – food spoilage, mycoses, toxin production

microscopic fungi exist in 2 morphologies yeast – unicellular, round ovoid shape, asexual reproduction (budding or transverse division) – also can form pseudohyphae Filamentous (“mold”) - hyphae – long filamentous fungi or molds; forms tangled mass=mycelium some exist in either form – dimorphic – characteristic of pathogens

yeasts Reproduces by budding or transverse division (asexual) Can form pseudohyphae (chains) Some can also form spores (sexual repro) Example: Saccharomyces cerevisae (Brewer’s or baker’s yeast)

Molds (hyphae)

Figure 5.15 7 7

Fungal nutrition all are _________________ majority are harmless __________living off dead plants & animals (saprophytes) secrete hydrolytic enzymes, digest externally some are parasites, living on the tissues of other organisms, but none are obligate; __________= fungal infections growth temperature 20o-40oC extremely widespread distribution, many habitats

Fungal Reproduction primarily through __________formed on special reproductive __________ asexual reproduction – spores are formed through budding (yeasts) or in __________or _______________________ (molds) sexual reproduction – spores are formed following fusion of male & female strains & formation of sexual structure sexual spores are one basis for __________

I. Asexual reproduction Molds - Reproduction Transverse fission Budding Spores (most common) Sporaniogpores – spores enclosed in head (sporangium) – sits atop stalk (___________________) Conidia – free spores

I. Asexual Reproduction Sporangiospores Stalk = Sac = Spores =

Conidia All form on top of stalk (conidiophore) I. Asexual Reproduction Conidia All form on top of stalk (conidiophore) Arthrospores – septate hypha – fragments break off Chlamydospores – spherical, thickened hyphal cell Blastospore = bud Phialospore – buds from vase shaped phialide Micro/macro conidium – small and large versions of conidia, 1 and 2+celled, respectively. Porospore – conidium that grows from pore You do NOT have to memorize these types of conidia! 

Conidia I. Asexual Reproduction

Spore types and representative genera I. Asexual Reproduction Spore types and representative genera Sporangiospores – Absidia, Mucor Arthrospores – Coccidiodes Chlamydospores/blastospores – Candida albicans Phialospores – Aspergillus, Penicillium Micro/microconidia – Microsporum, Fusarium Porospores - Alternaria You do NOT have to memorize these types of conidia! 

II. Sexual reproduction Involves fertilization – union of compatible nuclei Some can self-fertilize Can yield spores: Zygospore Ascospore Basidiospore

4 main divisions of molds based on sexual spore type II. Sexual Reproduction 4 main divisions of molds based on sexual spore type Zygomycota Ascomycota Basidiomycota Deuteromycota – no sexual spores?

Zygomycota Ascomycota Basidiomycota Detueromycota Sexual spores None or not described Asexual spores Sporangio- (some conidia) Types of conidia Conidia Var. conidia Hyphae Nonseptate or complete septa Porous septate Incompletely septate septate Lifestyle Mostly saprobes some parasites Many important species and pathogens Fleshy fruiting bodies; some plant parasites, 1 pathogen Some dimorphic; saprobes and some parasites examples Rhizopus, Mucor Agents of dermatophytosis, Histoplasma, Penicillium, Saccharomyces, Pneumocystis carinii Cryptococcus neoformans; mushrooms, puffballs, rusts, smuts Coccidioides immitis, Candida albicans, Cladosporium, Strachybotrys

Fungal pathogenesis (mycosis) Most fungi are not true pathogens (they don’t attack healthy people) Most are ______________– invade those with compromised immune systems (AIDS, cancer, diabetes) Degree of mycosis (disease) varies by mode of infection and organs involved Fungi also cause ______________– , and produce ______________–

Considered the most pathogenic fungus 19 19

Important fungal diseases Microorganism Associated Disease(s) Trichophyton spp. Epidermophyton spp. Microsporum spp. Tinea capitis (ringworm); Tinea cruris (jock itch); Tinea pedis (athlete's foot);Tinea unguum (finger and toenails); Tinea corporum (body); Tinea barbae (beard) Candida albicans vaginal yeast infections, oral thrush, nail fungus Coccidiodes Coccidiomycosis – lung/systemic – VERY deadly Blastomyces dermatitidis blastomycosis (skin, lungs, organs) Aspergillus spp. aspergillosis

ringworm Athlete’s foot Nail fungus

mycosis Blastomycosis Coccidiomycosis

Oral thrush – C. albicans

Case study: mucormycosis Mucor sp. – common mold of soil, bread, fruit etc. Opportunistic infection Mark Tatum – steroids suppressed his immune system Inhaled spores  infection in sinus Had to have sinuses removed including nose, eyes and face

mycosis

Benefits of fungi Decomposers of organic matter (recycle nutrients) Symbiosis with plant roots Produce antibiotics, organic acids, vitamins Fermentation (alcohol) Foods – bread, cheese; also eaten as foods

Identifying Fungi Media – cornmeal, blood, Sabouraud’s agar ID by asexual stages (sexual not common in lab cultures) Also physical characteristics: hyphae, colony morphology, color, other characteristics Genetic tests

Kingdom Protista Algae – photosynthetic, plant-like Protozoa – nonphotosynthetic, animal-like

Algae photosynthetic organisms contain chloroplasts with chlorophyll & other pigments; cell wall; may or may not have flagella kelps, seaweeds, euglenids, green algae, diatoms, dinoflagellates, brown algae, & red seaweeds microscopic forms are unicellular, colonial, filamentous macroscopic forms are colonial and multicellular most are free-living in fresh and marine water (you have seen examples off all of these in lab)

Fig. 5.26 Algae

Algae classified according to types of pigments & cell wall provide basis of food web in most aquatic habitats (plankton) produce large proportion of atmospheric O2 used for cosmetics, food & medical products _______________ cause red tides & produce toxins – paralytic shellfish poisoning

32 32

Dinoflagellates Paralytic shellfish poisoning – accumulation of toxins in clams and other shellfish Ciguatera – accumulation in fish - no antidote for toxin. Can be self-limiting. _______________ _______________ (pfiesteriosis)– parasite of fish and humans; algal blooms from agricultural runoff; also has potent toxins