Exploring the Fascinating World of Mycology at Basrah University

Basrah University Basrah University Faculty Education of Faculty Education of Qurna Biology Dept. Biology Dept. MYCOLOGY MYCOLOGY Lec Lec. . No. No. 1 1 Dr. Dr. Ismail Ismail jumha Abbas jumha Abbas PH. PH.D D in Microbiology in Microbiology & & molecular biology molecular biology Qurna

INTRODUCTION TO MYCOLOGY INTRODUCTION TO MYCOLOGY Mycology: Mycology: Is the science of studying a group of Is the science of studying a group of microorganisms known as fungi microorganisms known as fungi (Mycology = fungi, logy = science). Fungi (molds) fungi, logy = science). Fungi (molds) are a group of microorganisms living in nature, heterotrophic and microorganisms living in nature, heterotrophic and common in different habitats (soil, water, and air). common in different habitats (soil, water, and air). Fungal cell structures are differ from bacteria, plants Fungal cell structures are differ from bacteria, plants and animals in some features (Table 1). and animals in some features (Table 1). Table1. Differences between the fungal cell Table1. Differences between the fungal cell structures and other organisms structures and other organisms (Mycology = are a group of

Cell structures Bacteria Fungi plant Animals Cell wall + - + - + - - + + + + + Nucleus(Eukaryote) + + Ribosomes + + Mitochondria + + Endoplasmic Reticulum Golgi bodies + + + + - - - + - + Plastids + - Lomasomes - -

Fungal characteristics Fungal characteristics 1 1. Fungi are heterotrophic with no chlorophyll . Fungi are heterotrophic with no chlorophyll 2 2. Hyphae are the main body structure . Hyphae are the main body structure 3 3. . Hyphal Hyphal cell cell- -wall composed of chitin, wall composed of chitin, glucan or cellulose or cellulose 4 4. Eukaryotic cells (nuclei) . Eukaryotic cells (nuclei) 5 5. Reproduction by asexual and sexual methods . Reproduction by asexual and sexual methods 6 6. Spores are the main units of reproduction . Spores are the main units of reproduction 7 7. Fungi have different modes of nutrition . Fungi have different modes of nutrition 8 8. Fungi play important roles in environment . Fungi play important roles in environment glucan

Fungal nutrition Fungal nutrition There are three modes of nutrition in fungi There are three modes of nutrition in fungi 1 1. . Saprophytic fungi Saprophytic fungi Those are mostly living on the dead organic Those are mostly living on the dead organic substrates (plants and animals), substrates (plants and animals), eg skin, etc. So fungi are capable of degrading organic compounds by skin, etc. So fungi are capable of degrading organic compounds by excreting different enzymes ( excreting different enzymes (cellulase cellulase, protease, lipase, Therefore, fungi play a major role in the biodegradation process in Therefore, fungi play a major role in the biodegradation process in ecosystems. ecosystems. And And they are decomposers in the food they are decomposers in the food- -chain. 2 2. . Parasitic fungi Parasitic fungi: Many fungi live as parasitic on living plants, : Many fungi live as parasitic on living plants, animals and human. They cause various diseases. Many species animals and human. They cause various diseases. Many species plant are pathogens, so either obligate or facultative parasites plant are pathogens, so either obligate or facultative parasites 3 3. . Symbiotic fungi Symbiotic fungi. Some fungi are living with plant roots in a . Some fungi are living with plant roots in a mutualistic association both fungi and plants get benefit from each mutualistic association both fungi and plants get benefit from each other this is what so called other this is what so called mycorrhizal mycorrhizal fungi as as symbionts symbionts (fungi and (fungi and algae) algae) eg. Leaves. stems, fruits, seeds, hair, . Leaves. stems, fruits, seeds, hair, , protease, lipase, keratinase keratinase). ). chain. fungi . .Lichens Lichens are also live are also live

Fungal Reproduction Fungal Reproduction: : Fungi reproduce by two methods: Fungi reproduce by two methods: 1 1. Asexual reproduction . Asexual reproduction: : a. Fragmentation a. Fragmentation: Hyphae are fragmented into small : Hyphae are fragmented into small segments and each grows into a new hypha. segments and each grows into a new hypha. b. Budding b. Budding: This is common in yeasts. Each cell produces a : This is common in yeasts. Each cell produces a small bud. the bud grows up and separates into a new cell. small bud. the bud grows up and separates into a new cell. c. Fission c. Fission: One cell divides into two cells. : One cell divides into two cells. d. Sporulation d. Sporulation: The most common reproduction method in : The most common reproduction method in fungi. Spores are produced inside sporangia. Spores with fungi. Spores are produced inside sporangia. Spores with different shapes, colors, size. Spores often geminate into different shapes, colors, size. Spores often geminate into hyphae under favorable conditions or remain dormant hyphae under favorable conditions or remain dormant.

2 2. Sexual reproduction: . Sexual reproduction: Generally, three steps are involved during the sexual Generally, three steps are involved during the sexual reproduction ( reproduction (plasmogamy plasmogamy. . karyogamy - -Two Two cells (gametes) are fussed giving a fertile cell (zygote cells (gametes) are fussed giving a fertile cell (zygote). ). - - However, various methods are known in the fungal sexual However, various methods are known in the fungal sexual reproduction; reproduction; a. a. Planogametic Planogametic coupulation coupulation two motile gametes are fussed two motile gametes are fussed resulting into zygote. This includes resulting into zygote. This includes isogamy,heterogamy oogamy oogamy. . b. b. Gametangial Gametangial contact contact: Male and female : Male and female gametangia in contact, male nuclei moved into the female in contact, male nuclei moved into the female gametangium karyogamy karyogamy occurs and a zygote is occurs and a zygote is produced karyogamy and meiosis). and meiosis). isogamy,heterogamy and and gametangia become gametangium, , produced. . become

c. c. Gametangial Gametangial conjugation become close to each other become close to each other gametangia the zygote is produced the zygote is produced d. d. Spermatization Spermatization. In some fungi . In some fungi spermatia raceptive raceptive hyphae ( hyphae ( ) are formed, fertilization happens ) are formed, fertilization happens to give fertile cell ( zygote ) to give fertile cell ( zygote ) conjugation Tow matting hyphae are Tow matting hyphae are gametangia are formed and are formed and spermatia is ( is ( ) and ) and

Fungi growth Fungi growth Fungi generally grow on different substrates in Fungi generally grow on different substrates in nature and different media in the laboratory various nature and different media in the laboratory various factors affecting the fungus growth factors affecting the fungus growth including 1 1.Substrates .Substrates Natural and Natural and artificial artificial substrates are available for the growth of fungi. Each substrate available for the growth of fungi. Each substrate containing different containing different nutrient nutrient compounds. Carbon and Nitrogen sources are the main fungal growth and Nitrogen sources are the main fungal growth requirements. In addition to, some other minor requirements. In addition to, some other minor elements are elements are required. required. including, , substrates are compounds. Carbon

2 2. Temperature . Temperature: In general fungi grow at optimal : In general fungi grow at optimal temperature ( temperature (20 20- -25 25 C), However, some fungi may C), However, some fungi may grow at grow at 45 45 C ( C (thermophillic thermophillic fungi) or at low temperature ( temperature (Psychrophillic Psychrophillic). ). 3 3. pH . pH: Fungi often grow in an acidic medium with : Fungi often grow in an acidic medium with pH pH 5.5 5.5- - 6 6. . 4 4. Moisture . Moisture: Is important for the spore germination : Is important for the spore germination and growth and growth fungi) or at low

Fungal growth curve Fungal growth curve There are four growth phases within the fungal growth There are four growth phases within the fungal growth patron; patron; Lag phase, Lag phase, Log phase Log phase and declining phase ( Fig. and declining phase ( Fig.1 1) ) Growth Growth rate can rate can be measured on solid medium by be measured on solid medium by means of fungal colony diameter or by the fresh/ dry means of fungal colony diameter or by the fresh/ dry weigh of mycelium in liquid medium weigh of mycelium in liquid medium