SECOND SEMESTER 2020/2021 SESSION GROUP WORK ASSIGNMENT COURSE CODE: MCB212 SUPERVIED BY: PROF. MR. AMARE QUESTION: DISCUSS THE CLASSIFICATION OF FUNGI WITH THERE BENEFIT THE DEPARTMENT OF MICROBIOLOGY, FACULTY OF LIFE SCIENCES, AMBROSE ALLI UNIVERSITY, EKPOMA, EDO STATE. FEBRUARY,2022. 1 ACKNOWLEDGEMENT Group Leader: AWORUNSE KEHINDE GLORIA FLS/MCB/19/53762 E1106192 Asst. Group Leader: PAULINUS PROSPER UDO FLS/MCB/19/55778 E1103702 GROUP MEMBERS Names of Students OBAZE PERPETUAL IVIE EDORE SCHOLASTICA .O. FRANK MERCY OKHUELA Matriculation Number FLS/MCB/19/50647 FLS/MCB/19/59276 FLS/MCB/19/59276 FLS/MCB/19/51414 FLS/MCB/19/52167 FLS/MCB/19/56419 FLS/MCB/19/54809 E1102175 E1112675 E1111680 E1105149 E1102462 E1125081 E1106563 ONOWU ANTHONIA CHIMDUWU OFULU IFEOMA FAVOUR FLS/MCB/19/55731 FLS/MCB/19/58889 E1103948 E1107422 IFUEKO AIYEVBOSA IBEH SOPHIA CHIWENDU ODUTOLA HALLELUYA OLUWATOYIN EVBODAGHE OMONO JENNIFER OGETTE EDNA OKORO JOY ONI ODION DIVINE UWAIFO VICTOR FLS/MCB/19/51728 FLS/MCB/19/55041 FLS/MCB/19/59631 FLS/MCB/19/51482 FLS/MCB/19/51239 FLS/MCB/19/52467 FLS/MCB/19/58271 FLS/MCB/19/55731 FLS/MCB/19/50696 E1114145 E1106174 E1100449 E1113948 E1106419 E1105341 E1106955 E1103948 E1112845 OGBEREYIVWE NELLY FLS/MCB/19/54639 E1105280 ILONTUMHAN OSARUGUE SHELTER FAYEFUMMI OLUWAFEMI ELEFAN DANIEL ENOMAYO OGHONOMWENAKHIN SONIA ADETUNJI RACHEAL OLUWAFUNMILAYO 2 Student ID. FUNGI What is a Fungi? Fungi are Eukaryotic, Spore bearing organism that has absorptive nutrition and lacks chlorophyll; reproduces Asexually and Sexually or both and normally has cell wall called Chitin. Fungi are important decomposers that break down organic matter; live as parasite on animals, humans, and plants; Fungi secrete enzymes outside their body structure and adsorbs the digested food. that include microorganism such as Yeasts, Moulds and Mushroooms e.t.c. CLASSIFICATION OF FUNGI Fungi, can be classified based on their different bases: A. CLASSIFICATION OF FUNGI BASED ON THEIR MODE OF NUTRITION On the basis of nutrition, Kingdom Fungi can be classified into 3 groups Saprophytic: The fungi obtain their nutrition by feeding on dead organic substances E.g Rhizopus, Penicillin, and Aspergillus. Parasitic: The Fungi obtain their nutrition, by living on other living organism (Plant or Animals) and absorbs nutrients from their host E.g Taphrina and Puccinia. Symbiotic: 3 These fungi live by having an interpedently relationship association with other species in which both are mutually benefit. E.g Liches and Mycorrhiza. B. CLASSIFICATION OF FUNGI BASED ON THEIR TAXONOMICAL SYSTEMATIC . Zygomycota: These are formed by the fussion of two different cells. The sexual spores are known as Zygospore, while the asexual spores are known as Sporangiospore. The hypae are without the septa e.g Rhizopus, Absida, Mucor. 4 Rhizopus stolorifer, a Zygomycete that Grows on SimpleSugars. The fungus is often found on moist bread or fruit. Zygomycete is named for the zygosporangia characteristic of members of `the genus Rhizopus Ascomycota: They are also called Sac-Fungi they can be co-prophilous decomposers, Parasitic or Saprophytic Ascomycetes. Produces sexual spores called ascosphores, formed in Sac-like Structure called asci, and also small asexual spores called Conidia the hypae are narrow septate. E.g Penicillin, Yeasts, Aspergillus, Morels, Neurospora and Truffels. 5 The Typical Life Cycle of a Filamentous Ascomycete Basidomycota: They are also called Club Fungi This class includes common Mushrooms and Shelf fungi Sexual reproduction involve in the formation of Basidium (Basidiospores) Asexual reproduction can be either budding or asexual spore formation, or by fragmentation. Asexual Spore formation, however most often takes places at the end of specialized structures called Conidiophores. Hypae is divided by Septa. 6 Basidiomycota: The life Cycle of a Typical Soil Basidiomycetes Deuteromycota: They are otherwise called imperfect fungi (Anmorph) as they do not follow the regular reproduction cycles as the other fungi they do not reproduce Sexually. Asexual reproduction occurs by Conidia, they form Septate hypae E.g Coccidiodae, Immitis, Paracoccidiodies, Brasitiensis, Candida Albicon, e.t.c C. CLASSIFICATION OF FUNGI BASED ON THEIR USES 1. Some Fungi hels in recycling dead Organic matter. They are Sapotrophs e.g Rhizopus. 2. They Serve as Food E.g Mushrooms. 3. Medicines/Penicillin antibiotics is derived from a common Fungi Penicillium. 7 4. Bio-control agents, Fungi are involved in exploiting insects, other small worms and help in controlling pest E.g Trichoderma, Alternaria, Verticillium, Aspergillius. Candida Fusarium e.t.c 5. Some Fungi causes food Spoilage e.g Yeasts and Molds 6. Some serves for enhancing food quality and quantity, e.g Yeasts. D. Classification of Fungi by Morphological Features According to cruickshant et al, (1973) morphologically fungi can be categlorized into four(4) main groups: THE MOULDS They grow into long filamentous from (hypae) which branch and into a mesh work, the mycelium. They reproduce by the formation of various kinds of Spores such as Sporangiospore in Rhizopus spp, Mucor spp, and Condida form. common genera of moulds include: Acremonium. Alternaria, Aspergillus, Cladosporium, Fusarium, Mucor, Penicillium, Rhizopus, Stachybotrys, Trichoderma and Trichophyton. THE YEASTS The Yeasts are Unicellular Fungi they reproduce by budding, they differ from most fungi which grows as thread like hypae the common baker’s yeast Saccharomyes Cerevisiae. The genus Cryptococcus, which includes C. Neoformans, a pathogen of Human. THE YEAST-LIKE FUNGI 8 These are similar to the yeast in growing by forming blastospore. The blastospore here can grow into a group of flamentous cells joined end to end called Psuedohypae or Psuedomycellium example Candida alblcans. DIMORPHIC FUNGI Dimorphic means two (2) morphological forms they groups other in hypae or Yeast according to the conditions of occurance. Growth usually takes place in the hypae mycelial form as saprophytes and in the yeast form as parasitic in animal body examples includes: Histoplasma, Capsulatum, Blastomyces dermatitidis. E. CLASSIFICATION BASED ON PATHOGENIC NATURE 9 Based on the pathogenic potential, Fungi may be considered as: 1. PRIMARILY PATHOGENIC: Those Fungi which are able to cause infections in healthy individuals for example, thermally dimorphic Fungi 2. OPPORTUNISTIC PATHOGENS: Those Fungi that are able to cause infections in patients who are immuno- compromised due to some other infections or diseases or who are receiving immuno-suppresive drugs E.g Aspergillus Flavus. 10 CLASSIFICATION OF FUNGI BASED SPORE PRODUCTION On the basis of the organisation of the vegetative thallus, the morphology of reproductive structures, the way of spores production and particular life cycle involved the kingdom mycota is classified into following divisions. Phycomycetes • It includes the simplest type of fungi. It is also called as Algae-Fungi because most of the characteristics of them are similar to algae like Vaucheria. • They have simple thallus which is unicellular or coenocytic or aseptate filaments. • They reproduce asexually by the formation of zoospores or non-motile spores. • Sexual reproduction is isogamous or heterogamous which takes place by gametangial contact. • The diploid phase is represented by zygote. • Phycomycetes has been classified into subclasses: (a)oomycetes and( b) zygomycetes. Oomycetes • Oomycetes range from a primitive unicellular thallus to a profusely branched filamentous mycelium. • Many members of them are terrestrial and obligate parasites. 11 • Asexually they reproduce by biflagellate zoospores. • Sexual reproduction is oogamy that involves the fusion of male and female gametes to form oospore. • Oospore undergoes meioses to produce haploid biflagellate zoospores. • Example; Phytophthora infestans(causes potato blight) Zygomycetes • The group is named zygomycetes because a diploid resting spore called the zygospore is formed during the life cycle. • They are mostly saprophytic, some others are parasites on plants and animals. • The vegetative body is mycelium which is well developed, profusely branched and coenocytic. • The absence of motile sexual or asexual cells. • The asexual reproduction takes place by sporangiospores, aplanospores or by conidia. • Sexual reproduction occurs by conjugation of gametangia resulting in the formation of zygospore. • Examples; Rhizopus, Mucor etc ASCOMYCETES: The species of ascomycetes are called the sac fungi because they produce sexual pores within the sac-like vascus. General Characteristics • Ascomycetes are mostly terrestrial occurring as saprophytes or parasites. 12 • They have well-developed, branched, septate mycelium except yeast. Yeast is a unicellular fungus. • Asexually they reproduce by non-motile spores, conidia, oidia or chlamydospores. • Sexual reproduction takes place by the fusion of gametangia of opposite mating types. • There is absence of motile cells. • Examples, Saccharomyces cerevisiae, Penicillium, Aspergillus etc. BASIDIOMYCETES: • The members of basidiomycetes are saprophytic or parasitic. The group is named basidiomycetes as they produce the basidiospores at the club-shaped basidium during sexual reproduction. • Mycelium is highly developed, profusely branched and septate. • The mycelia are differentiated into two mating types; (+ve) and (-ve). • There are two kinds of mycelium; primary mycelium and secondary mycelium. • Asexual reproduction takes place by fragmentation, budding, oidia, conidia or chlamydospore. • The dikaryotic cell is formed during sexual reproduction. • The absence of motile cell throughout the life cycle. • Basidiomycetes are the most advanced fungi as their fructifications are often large and prominent. • Examples; Mushrooms, Puccinia, Ustilago etc. 13 DEUTEROMYCETES (The Imperfect Fungi) • Deuteromycetes compromises more than 17000 species of the diverse habits and habitats. It is considered as an artificial class of fungi. • The fungi are saprophytes as well as parasites. Parasitic fungi cause serious diseases to plants, animals including human beings. • Some of them are unicellular while others are multicellular. • They reproduce asexually by conidia along with some other types of spores. • The sexual reproduction is entirely absent. • The asexual stage or imperfect stage in Deuteromycetes is well defined. But the sexual or perfect stage is absent in life cycle, therefore, they are called ‘Fungi Imperfecti’. • Example; Alternaria, Fusarium, Helminthosporium etc. F. CLASSIFICATION BASED ON VIRULENCE Primarily Pathogen can establish infection on normal host, Opportunistic Pathogens causes disease in individual with compromised host defense mechanisms. 14 The Primarily Systematic Fungal Pathogens include Coccidiodes immitis, Histoplasma, Capsulatum, Blastomyces, Dermatitidis, and Paracoccidioides brasiliiensis. The Opportunistic Fungal Pathogens include: Crytococcus neoforman, Candida, Aspergillus spp, Penicillium marneffei, the Zygomycetes, Trichosporon beigeli and Fusarium spp. BENEFIT OF FUNGI Human have been indirectly aware of fungi since the Humans have been indirectly aware of fungi since the first loaf of leavened bread was baked and the first tub of grape must was turned into wine. Ancient peoples were familiar with the ravages of fungi in agriculture but attributed these diseases to the wrath of the gods. The Romans designated a particular deity, Robigus, as the god of rust and, in an effort to appease him, organized an annual festival, the Robigalia, in his honour. Fungi are everywhere in very large numbers—in the soil and the air, in lakes, rivers, and seas, on and within plants and animals, in food and clothing, and in the human body. Together with bacteria, fungi are responsible for breaking down organic matter and releasing carbon, oxygen, nitrogen, and phosphorus into the soil and the atmosphere. Fungi are essential to many 15 household and industrial processes, notably the making of bread, wine, beer, and certain cheeses. Fungi are also used as food; for example, some mushrooms, morels, and truffles are epicurean delicacies, and mycoproteins (fungal proteins), derived from the mycelia of certain species of fungi, are used to make foods that are high in protein. Studies of fungi have greatly contributed to the accumulation of fundamental knowledge in biology. For example, studies of ordinary baker’s or brewer’s yeast (Saccharomyces cerevisiae) led to discoveries of basic cellular biochemistry and metabolism. Some of these pioneering discoveries were made at the end of the 19th century and continued during the first half of the 20th century. From 1920 through the 1940s, geneticists and biochemists who studied mutants of the red bread mold, Neurospora, established the one-gene–one-enzyme theory, thus contributing to the foundation of modern genetics. Fungi continue to be useful for studying cell and molecular biology, genetic engineering, and other basic disciplines of biology. The medical relevance of fungi was discovered in 1928, when Scottish bacteriologist Alexander Fleming noticed the green mold Penicillium notatum growing in a culture dish of Staphylococcus bacteria. Around the spot of mold 16 was a clear ring in which no bacteria grew. Fleming successfully isolated the substance from the mold that inhibited the growth of bacteria. In 1929 he published a scientific report announcing the discovery of penicillin, the first of a series of antibiotics—many of them derived from fungi—that have revolutionized medical practice. Another medically important fungus is Claviceps purpurea, which is commonly called ergot and causes a plant disease of the same name. The disease is characterized by a growth that develops on grasses, especially on rye. Ergot is a source of several chemicals used in drugs that induce labour in pregnant women and that control hemorrhage after birth. Ergot is also the source of lysergic acid, the active principle of the psychedelic drug lysergic acid diethylamide (LSD). Other species of fungi contain chemicals that are extracted and used to produce drugs known as statins, which control cholesterol levels and ward off coronary heart disease. Fungi are also used in the production of a number of organic acids, enzymes, and vitamins. 17 REFERENCES 1. Horowitz- Brown, S., et al. 2018. Morphological transitions governed by density dependence and lipoxygenase activity inAspergillus Flavus. Appl. Environ. Microbiol. 74:5674 2. Carris, L. M., C. R. Little and C. M. Stilies. 2012. Introduction to Fungi. 3. David Hibbett et al. Mycologia. Nov/Dec 2016 4. Mary E Brandt.David W. Warnock. Manual of Clinical Microbiology(pp.1932-1943). May 2015 5. Dr. Tanuja, University Department of Botany, Patliputra University 6. Cruickshank, R, et al. Medical Microbiology. 1975 7. Lichtwardt RW, et al. Mycologia. 2011 18