FUNGI An Overview

Characteristics of Fungi Eukaryotic Nonphotosynthetic ( heterotrophic) Most are multicellular Most are microscopic molds or yeasts The study fungi is known as MYCOLOGY.

Structure of Fungi Filaments of fungi are called hyphae. The cell walls contain chitin. The MYCELIUM is a mat of hyphae visible to the unaided eye ( bread mold) Some hyphae may divided by cross sections called septa Septated Unseptated - coenocytic

Reproduction Most fungi reproduce both sexually and asexually. Asexual reproduction – production of various types of spores Sporangiophores- upright stalk with an enclosed sac ( bread mold) Conidia - upright stalk with no enclosed sac (penicillin) Fragmentation – hyphae dry out and shatter releasing individual cells that act like spores (athlete’s foot) Budding – small offspring

Sexual reproduction “plus and minus” mating types Hyphae of different mating types fuse and give rise to a specialized structure that produces spores ( diploid) Most fungi are haploid throughout most of their life cycle When environmental conditions are favorable, asexual reproduction occurs rapidly. When unfavorable conditions stress the organism, sexual reproduction occurs and the offspring have an increased likehood that they will be better suited for the environment.

Fungi decompose dead plant and animal matter. Called saprophytes, they act as recyclers of dead organic matter, obtaining food from this material. Hyphal tips release enzymes that eventually decompose and release organic materials into the surrounding environment. Saprophytic fungi appear on dead trees, logs, plant litter such as leaves, and even dead insects and animals. Examples: "Gem-studded Puffball" (Lycoperdon perlatum) and "Turkey Tail"(Trametes versicolor).

Fungi and Humans Many people have allergies triggered by mold. Fungal skin infections – skin, nails and hair Ringworm, athlete’s foot Internal organs - Histoplasmosis

Fungi in Industry Fungi produce many products used in the medical field such as penicillin, cephalosporin antibotics, cortisone Fungi are used in genetic engineering – vaccine for hepatitis B was developed using the yeast plasmid as the vector. Yeast is used to make ethanol. Yeast are known for making breads rise.

Fungi in the Food Industry Mushrooms, morels and truffles are widely consumed by humans.

Fungi are Plant Pathogens Many fungi attack grain or fruit.

Lichen – symbiotic relationship between algae and fungi Fungi form beneficial partnerships (symbiosis) with other organisms such as trees and flowering plants: Algae hyphae Lichen – symbiotic relationship between algae and fungi

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