Biological Sciences
Fungi Phylum
The Fungi Phylum is a diverse group of organisms that includes molds, yeasts, and mushrooms. Fungi are eukaryotic organisms that obtain nutrients through absorption, and they play important roles in ecosystems as decomposers and as symbiotic partners with plants. This phylum is characterized by their unique cell walls made of chitin and their ability to produce spores for reproduction.
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7 Key excerpts on "Fungi Phylum"
No longer available |Learn more- (Author)
- 2014(Publication Date)
- Academic Studio(Publisher)
However, little is known of the true biodiversity of Kingdom Fungi, which has been estimated at around 1.5 million species, with about 5% of these having been formally classified. Ever since the pioneering 18th and 19th century taxonomical works of Carl Linnaeus, Christian Hendrik Persoon, and Elias Magnus Fries, fungi have been classified acc ording to their morphology (e.g., characteristics such as spore color or microscopic features) or physiology. Advances in molecular genetics have opened the way for DNA analysis to be incorporated into taxonomy, which has sometimes challenged the historical groupings based on morphology and other traits. Phylogenetic studies published in the last decade have helped reshape the classification of Kingdom Fungi, which is divided into one subkingdom, seven phyla, and ten subphyla. Etymology The English word fungus is directly adopted from the Latin fungus (mushroom), used in the writings of Horace and Pliny. This in turn is derived from the Greek word sphongos /σφογγος (sponge), which refers to the macroscopic structures and morphology of mushrooms and molds; the root is also used in other languages, such as the German Schwamm (sponge), Schimmel (mold), and the French champignon and the Spanish champiñon (which both mean mushroom). The use of the word mycology , which is derived from the Greek mykes /μύκης ( mushroom) and logos /λόγος (discourse), to denote the scientific study of fungi is thought to have originated in 1836 with English naturalist Miles Joseph Berkeley's publication The English Flora of Sir James Edward Smith, Vol. 5. Characteristics Before the introduction of molecular methods for phylogenetic analysis, taxonomists considered fungi to be members of the Plant Kingdom because of similarities in lifestyle: both fungi and plants are mainly immobile, and have similarities in general morphology and growth habitat.
eBook - PDF- Mary Ann Clark, Jung Choi, Matthew Douglas(Authors)
- 2018(Publication Date)
- Openstax(Publisher)
Most familiar mushrooms belong to this division. Fungi that have no known sexual cycle were originally classified in the “form phylum” Deuteromycota, but many have been classified by comparative molecular analysis with the Ascomycota and Basidiomycota. Glomeromycota form tight associations (called mycorrhizae) with the roots of plants. Chapter 24 | Fungi 697 24.3 Ecology of Fungi Fungi have colonized nearly all environments on Earth, but are frequently found in cool, dark, moist places with a supply of decaying material. Fungi are saprobes that decompose organic matter. Many successful mutualistic relationships involve a fungus and another organism. Many fungi establish complex mycorrhizal associations with the roots of plants. Some ants farm fungi as a supply of food. Lichens are a symbiotic relationship between a fungus and a photosynthetic organism, usually an alga or cyanobacterium. The photosynthetic organism provides energy from stored carbohydrates, while the fungus supplies minerals and protection. Some animals that consume fungi help disseminate spores over long distances. 24.4 Fungal Parasites and Pathogens Fungi establish parasitic relationships with plants and animals. Fungal diseases can decimate crops and spoil food during storage. Compounds produced by fungi can be toxic to humans and other animals. Mycoses are infections caused by fungi. Superficial mycoses affect the skin, whereas systemic mycoses spread through the body. Fungal infections are difficult to cure, since fungi, like their hosts, are eukaryotic, and cladistically related closely to Kingdom Animalia. 24.5 Importance of Fungi in Human Life Fungi are important to everyday human life. Fungi are important decomposers in most ecosystems. Mycorrhizal fungi are essential for the growth of most plants.
eBook - PDF- N A Khan(Author)
- 2008(Publication Date)
- CRC Press(Publisher)
CHAPTER 6 Fungi 1. INTRODUCTION Fungi are eukaryotic organisms that contain more than 300,000 species and some (few hundred) have been recognized as human pathogens, causing mild infections to serious life-threatening diseases. The majority of fungal pathogens cause opportunistic infections, i.e., normally limited to individuals with a weak immune system. The increasing numbers of immunocompromised patients especially due to HIV have made a large part of the human population susceptible to the fungal infections. Similar to protozoa, the study of mycology began with the discovery of microscope. They were first observed by Robert Hooke in 1667, followed by Leeuwenhoek in 1689 observing their structure and budding. Later Antonio Micheli (1729) described hundreds of fungi as independent organisms. Thus far, the majority of fungi identified were plant pathogens and were identified from the decaying matter. For the next 100 years, the major focus in the field of mycology remained in their role as plant pathogens. However, in 1839, fungus ( Trichophyton ) was identified as the causative agent of human disease causing cutaneous infections. 2. TAXONOMY As indicated previously, all livings beings are divided into two domains (Prokaryota and Eukaryotes). Within Prokaryota, there are two kingdoms, Archaebacteria and Eubacteria (Bacteria). Eukaryota is composed of five kingdoms including Protozoa, Chromista, Plantae, Animalia and Eumycota. Here, fungi are classified into two domains, Chromista and Eumycota, which are further divided into 5 phyla as follows, 2.1 Chromista (also called Fungi Imperfecti or Deuteromycota) 1. Phylum Hyphochytriomycota Fungi exhibit asexual reproduction and no known sexual stage. Fungi have a haploid vegetative stage and possess cellulose-containing cell walls. These include fungi that are mostly unknown to humans. 2. Phylum Oomycota (also called water moulds) Fungi exhibit asexual reproduction and no known sexual stage.
eBook - PDF- D.H. Howard(Author)
- 2002(Publication Date)
- CRC Press(Publisher)
II. NOMENCLATURE OF HIERARCHAL GROUPS The pathogenic organisms traditionally considered as fungi* are now distributed among three biologic kingdoms: Fungi, Straminipila, and Protoctista (3). The bulk of this book is devoted to the members of the kingdom Fungi. Also included, however, is a consideration of the zoopathogenic members of the kingdoms Straminipila and Protoctista. (See Chap. 2.) The phyla to be considered in this book are listed in Table 1. Opinions on the nomenclature of hierarchal groups vary somewhat among taxonomists. For example, the terms Mycota and Fungi have both been used to designate the kingdom to which most of the human pathogens belong (4). Likewise, at one time mycologists used the term division instead of phylum (2) but more recently the word phylum has been widely adopted in fungal taxonomy. Authors in this book have used one term or the other as alternative words for the two highest hierarchal categories. I have let stand whichever usage the author chooses for these categories. In this summary chapter, the various taxonomic groups are the ones that contain animal pathogens (zoopathogens) and are covered in this book. The decisions on coverage within these groups have been left up to the authors selected. III. THE KINGDOM FUNGI A. Chytridiomycota This phylum comprises those members of the kingdom Fungi that produce motile cells in their life cycles (3). There are five orders of such pathogens or commensals within the single class of Chytridiomycetes (Table 2). The * Fundamental descriptions of fungi may be found in the textbooks on medical mycology by K.J. Kwon-Chung and J.E.Bennett (2) and on fundamental mycology by O.J.Alexopoulos, C.W. Mims, and M.Blackwell (3). A glossary of terms employed in this introduction will be found at the end of the chapter. 2 PATHOGENIC FUNGI IN HUMANS AND ANIMALS zoospores, produced by asexual reproduction of members of four of the five orders, have a single, smooth, posteriorly directed whiplash flagellum.
eBook - ePubWood Microbiology
Decay and Its Prevention
- Robert A. Zabel, Jeffrey J. Morrell(Authors)
- 2020(Publication Date)
- Academic Press(Publisher)
Chapter ThreeThe characteristics and classification of fungi and bacteria
Abstract
This chapter discusses the classification of fungi and bacteria in related to the classic approach using morphology vs more recent developments using DNA sequencing methods.Keywords
Fungi; Bacteria; White rot; Brown rotFungi and bacteria are the principal microorganisms that invade wood during its growth, processing, storage, or use, causing decay or other property changes.Contents
Outline- Fungi in relation to other life forms 56
- Bacteria 58
- Fungi 59
- Macroscopic appearances of fungi 60
- Microscopic features of fungi 62
- Hyphal wall structure 64
- Fungal ultrastructure 67
- Specialized hyphae 68
- Cultural characteristics 70
- DNA sequencing methods 71
- Classic fungal identification by culturing 71
- Fungal reproduction 73
- Life cycles 76
- Reproductive capacity 79
- Fungal variability 79
- Growth requirements 81
- A classification of fungi 81
- Basidiomycota 84
- Agaricales 85
- Hymenochaetales 86
- Gloeophyllales 86
- Boletales 86
- Polyporales 87
- Russulales 87
- Cantharellales 88
- Deuteromycetes or fungi imperfectii 88
- A classification of bacteria 89
- Cytophagales 90
- Gram-negative facultatively anaerobic rods 90
- Gram-negative, aerobic rods, and cocci 91
- Endospore-forming rods and cocci 91
- Actinobacteria 91
- The roles of fungi and bacteria in ecosystems and human affairs 92
- Summary 93
- References 95
- Further reading 97
An understanding of the decay process and its prevention or control depends, in part, on understanding the features and capabilities of these decay agents. This chapter emphasizes the unique nature of fungi and their relationship to the other major life forms. It reviews fungal structures, growth patterns, life cycles, reproductive modes, and variable features of fungi, placing emphasis on the wood-inhabitors. Classification systems are presented to facilitate the taxonomic placement and recognition of some of the major wood-inhabiting microorganisms. Since bacteria cause only minor damage to structural wood in most environments, they are only briefly covered.
eBook - PDF- J. W. Deacon(Author)
- 2009(Publication Date)
- Wiley-Blackwell(Publisher)
Many other ascomycetous fungi degrade cellulose and other structural polymers; e.g. Chaetomium in soil and composts, Xylaria and Hypoxylon as agents of wood decay, Sordaria and Ascobolus in herbivore dung, and Lulworthia on wood in estuarine environments (Chapter 11). Basidiomycota According to Kirk et al. (2001), the Basidiomycota con- tains about 30,000 described species, which is 37% of the described species of true fungi. Although the most familiar examples of this group are the mushrooms and toadstools, there is an enormous diversity of species, including basidiomycetous yeasts, many important plant pathogens, and some serious human pathogens. The one single feature that characterizes the group is the basidium in which meiosis occurs, leading to the production of sexual spores (basidiospores) that usu- ally are produced externally on short stalks termed sterigmata (Fig. 2.19). Several other features are found in the Basidiomycota. The hyphae often have a complex dolipore septum (Chapter 3) that prevents nuclei from moving between different hyphal compart- ments. The cell wall typically is composed of chitin and glucans (but chitin and mannans in the yeast forms). The nuclei typically are haploid, but throughout most of the life of a colony each hyphal compartment contains two nuclei, representing two different mating compatibility groups. A mycelium of this type is termed a dikaryon. The significance of this will be explained shortly. Taxonomy and relationships The Basidiomycota is a monophyletic group (all of its members having a common ancestry) and is a sister group to the Ascomycota. In other words, both of these groups have a common ancestor. Three major sub-groups are recognized within the Phylum Basidiomycota: 1 Urediniomycetes, including the rust fungi (Uredinales) which are economically significant plant pathogens of many crops and wild plants.
- Srinivasulu, B(Authors)
- 2018(Publication Date)
- Daya Publishing House(Publisher)
5 : Classifcation of Fungi Numerous schemes of classifcation have been proposed and some have been adopted. A generally accepted scheme for fungal classifcation has been published by the Commonwealth Mycological Institute (1983) and is reproduced here. The scheme is based on common ending for order, class, divisions, names etc. These are Division: -mycota; Sub-division: -mycotina; Class: -mycetes; Sub-class: -mycetidae; Order: -ales; and Family-ceae. Important Characters Division 1: Myxomycota Slime moulds Plasmodial forms Thallus is plasmodium True mycelium is absent. This ebook is exclusively for this university only. Cannot be resold/distributed. Class I: Plasmodiophoromycetes Endoparasitic slime moulds. Obligate parasites of vascular plants Thallus is plasmodium a) Sporangiogenous Plasmodium - Sporangial zoospores b) Cystogenous plasmodium - Cyst Zoospores ik Bifagellate Zoospores - Heterocont zoospores. Sexual reproduction - Isogamous planogametic copulation. ik Cause hypertrophy and hyperplasia of host tissue. Division 2: Eumycota True fungi. Non-plasmodial flamentous forms with cell wall. Well-developed flamentous thallus. Sub-Division a) Mastigomycotina Motile spores (Zoospores) are present. Flagellate zoospores Sexual spores - Oospore Sexual reproduction - gametangial contact (or) gametangial copulation b) Zygomycotina No motile spores. Produce non-motile spores - Aplanospores Well-developed coenocytic mycelium This ebook is exclusively for this university only. Cannot be resold/distributed. Sexual reproduction - gametangial copulation c) Ascomycotina They are called ‘sac fungi’.
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