KMU Fungi Some photos from Google Some videos from Youtube

KMU 1. Introduction Two types of fungi-transmission electron micrograph (a) yeast (b) mold (C) A mold growing on a graphfruit  Fungi ( 균류 ) - Contain nucleus and spore ( 포자 ). Do not have chlorophyll. Grow by sexual and asexual reproduction. Generally contain chitin in the cell wall of which structure is filamentous.  Types (1) yeast ( 효모 ) : single cell type (2) mold ( 곰팡이 ) : filamentous type, multi-cell  Play a role in carbon recycle  Contains intracellular organelles

KMU 2. Classification, structure and growth (1) Structure of fungi Figure. Mycellium, hypha, septum General fungi  Hypha (pl. hyphae, 균사 ) : a single fungal strand (thin and threadlike unit)  Mycelium ( 균사체 ) : an interwoven mass of all the hyphae  Septum ( 격벽 ) : partitions between cells in each hypha. Having pores permitting the transfer of the cytoplasmic fluid  Chitin ( 키틴 ) : main component of the cell wall. Consisting of polysaccharides (e.g.: cell wall of insect, crab…)  Spore ( 포자 ) : a reproductive cell able to become a hypha by itself highly resist on harsh environments 그림. 균류의 성장 Spore Spore germination

KMU  Heterotrophic ( 종속영양형 ) : all fungi live on preformed organic matter.  Excretion of enzyme : absorption of nutrients by excreting hydrolase for enzymatic digestion of macromolecules e.g.) cellulase : cellulose hydrolysis ligninase : lignin hydrolysis in plants amylase : starch hydrolysis  Carbohydrate storage material : glycogen  Growth pH : pH 5-6  Fungi can live at acidic conditions  Contaminate the acidic foods (bread, cheese) (sour cream, yoghurt, orange) (2) Nutrition in fungi Figure, Products of fungal activity

KMU (3) Reproduction in Fungi  Reproduction ( 생식 ) : Asexual ( 무성 ) + Sexual ( 유성 ) (1) Asexual reproduction : 1) No meiosis ( 감수분열 ) by cell fusion and nucleus exchange 2) By mitosis ( 체세포분열 ), two genetically-identical daughter cells are made from one cell. 3) Genetically simple  sensitive on environmental changes (2) Sexual reproduction ( 유성생식 ) 1) Involves cell fusion and spore formation 2) The nuclei of fungal cells are haploid ( 반수체, n) : Each nucleus contains a single set of chromosomes. 3) Begins with the fusion of cells  Zygote (fused cell, 접합자 ) : a diploid cell (haploid (n)  diploid (2n))  Meiosis ( 감수분열 ) : Results in daughter cells that each have a single set of chromosomes  Sexually produced haploid spore 4) Genetically diverse  can survive at various environments 유성생식 동영상

KMU 포자낭 (sporangium) 포자낭병 (sporangiophore) 포자 (sporangiospore) 감수분열 접합포자 (zygospore)

KMU 3. Divisions of Fungi (1) Zygomycetes  Zygomycetes ( 접합균류 ) : fungi forming zygospores by sexual reproduction - Zygospore ( 접합포자 ) : contains thick cell walls - Do not have septa - Undertake both sexual and asexual reproduction - General fungi growing on bread (Rhizopus stolonifer) Figure. Zygomycetes

KMU (2) 자낭균류  Ascomycetes ( 자낭균류 ) : a fungi forming ascus ( 자낭 ) - Ascus ( 자낭 ) : a tiny spore-containing sac with 8 ascospore ( 자낭포자 ) - About 30,000 of ascomycetes were identified. - Sexual and asexual reproduction. Contain multi-porous septum - Yeast, green mold (Penicillium), Aspergillus, big mushroom, plant pathogen  Penicillium sp. ( 푸른곰팡이 속 ) - Antibiotics production - Cheese fermentation 효  Aspergillus 속 ( 검정곰팡이 속 ) - contaminant in cooked rice - produce food toxin (aflatoxin) - Used for production of citric acid vinegar, soy source Figure. Ascus, ascospore, green mold, yeast

KMU  Basidiomycetes ( 담자균류 ) : a fungi forming basidium ( 담자기 ) - General mushroom, club fungi - Mushroom : general name of basidiocrap ( 담자과 ), a spore-forming unit - About 25,000 species Figure. Basidiomycetes (3) Basidiomycetes

KMU 3. Beneficial and Harmful Fungi (1) yeast  Yeast ( 효모 ) : an ascomycetes growing with budding  Budding ( 출아 ) : an asexual reproduction in which a new cell grows at the periphery of the parent cell and then pinches off.  Oval type of single cell (length, about 8 μm; diameter, 5 μm  Sexual reproduction also occurs in yeasts  Examples of yeasts (1) Candida albicans : ‘yeast infection’ in women (2) Saccharomyces cerevisiae : baking and alcohol-fermenting yeast (3) S. ellipsoideus : alcohol-fermenting yeast 알코올 발효 효모  A model microbe for studying sugar metabolism (glycolysis, Kreb cycle, oxidative phosphorylation)  An important microorganism in biotechnology Figure. Microscopic pictures of yeasts

KMU (2) Fungi and Human disease  Yeast infection ( 효모감염 ) : caused by Candida albicans infection 1) Disease in female genitals - Normal state : lactic acid bacteria produce lactic acid to prevent the growth of C. albicans. - Abnormal state : Excess antibiotics eliminate lactic acid bacteria.  C. albicans grow and the disease occurs. - Solution : treatment of anti-fungal agents and intake of lactic acid bacteria 2) Disease in mouth - C. albicans lives normally in mouth. - By destroy of immune system (AIDS) or miss-balance of M/O population - stomatitis ( 아구창 ) Figure. Examples of yeast infection