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1 Need a little help isolating? Try this…A split plate selective media MacConkey – CNA/Blood CNA/Blood (red side) G+ grow better here WARNING! G- may still show up MacConkey (pink side) Should only allow G- to grow These plates can be found in refrigerator on right side of middle shelf Added benefit – IF your G- organism uses lactose the colonies will appear pink on MacConkey
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2 Chapters 10 & 11 Classification of Microorganisms - Archae & Bacteria
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3 Whittaker’s Five-Kingdom System: Procaryotae (Monera) - prokaryotes, unicellular Protista - eukaryotic, generally unicellular (algae, protozoa) Fungi - eukaryotic, generally multicellular, saprophytic, chitin Plantae - eukaryotic, multicellular, photosynthetic Animalia - eukaryotic, multicellular, ingest food
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4 Three Domains (Woese,1978) Based on comparison of sequences of ribosomal RNA (rRNA) also differ in: lipid membrane structure tRNA structure response to antibiotics (see table 10.1 for details) Domains are a higher level of organization than Kingdoms
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5 D O M A I N S Eubacteria - contains the bacteria (prokaryotic) Archaea - contains the archeabacteria (prokaryotic) Eucarya - contains all the eukaryotic kingdoms
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6 THREE DOMAINS
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7... … …. ….....… End Chapter 10
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8 Bacteria Bacteria are classified using Bergey’s Manual of Systematic Bacteriology Bergey’s Manual is divided into four volumes: Division within Bergey’s Manual are based on characteristics such as: Gram reaction, cell shape, cell arrangement, oxygen requirements, motility, metabolic properties
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9 Bergey’s Manual Volumes I - IV I. Gram-negative bacteria of medical and industrial importance II. Gram-positive bacteria of medical and industrial importance III. Other Gram-negative bacteria IV. Actinomycetes and other Gram-positive bacteria review table 11.1 pages 307-309
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10 Bacterial Groups Be familiar with major groups in Table 11.1 Know major characteristics which set each group apart from the others (including habitat and special features) Be able to identify or place important genera within the appropriate group
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11 Spirochetes Gram negative cell wall morphology – helical (corkscrew shaped) motility by axial filaments (similar to flagella, but located inside the periplasmic space) Habitats: aquatic, animal parasites Important genera: Treponema & Borrelia T. pallidum = causative agent of syphilis B. burgdorferi = causative agent of Lyme’s disease (transmitted by deer tick)
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12 Aerobic, motile, helical/vibrioid bacteria Gram negative cell wall morphology either helical or vibrioid (comma shaped) some fix nitrogen soil and aquatic habitats, human intestinal tract and oral cavity Important genera: Spirillum Azospirillum – associated with plant roots, nitrogen fixer important to agriculture Campylobacter - a ‘food poisoning’ bacteria, 1 in 1000 Guillain-Barr Syndrome Bdellovibrio - predator on bacteria
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13 Gram-negative, aerobic rods and cocci many industrially, medical, and environmentally important bacteria. Habitats include soil, water, animal parasites
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14 Important G- Important genera: Pseudomonas – opportunistic infections in burns Burkholderia Legionella – Legionnaire’s Disease Neisseria - STD Brucella Bordetella – whooping & kennel coughs Francisella Rhizobium Agrobacterium
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15 Facultatively anaerobic, Gram-negative rods many important pathogens Habitats include soil, plants, animal respiratory and intestinal tracts many in this group known also as "enterics" (found in human intestine) Important genera: Escherichia, Salmonella, Shigella, Klebsiella, Yersinia, Vibrio, Enterobacter, Hemophilus, Gardnerella, Pasteurella
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16 Anaerobic, Gram-negative rods obligate anaerobes (can not live in presence of O 2 ) Habitats: mostly in intestinal tracts, some in mouth and genital tract & some of the most common organism in the intestine Important genera: Bacteriodes Fusobacterium
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17 Dissimilatory sulfate-reducing or sulfur reducing bacteria Gram negative cell wall found in anaerobic sediments reduce oxidized forms of sulfur to H 2 S dissimilation = nutrients not assimilated but rather excreted Important genera: Desulfovibrio
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18 Rickettsias & Chlamydias Gram negative cell wall, obligate intracellular bacteria many important pathogens, parasites of arthropods and other animals Important genera: Rickettsia Coxiella Ehrlichia - flu-like disease transmitted by ticks Chlamydia – sexually transmitted NGU (nongonococcal urethritis)
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19 Mycoplasmas no cell wall (G- reaction), pleomorphic (variable shape) parasites of animals, plants, insects some pathogens Important genera: Mycoplasma – normal vaginal flora that can opportunistically cause fallopian tube infection
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20 Gram-positive cocci some important pathogens and industrial organisms found in soils; skin and mucous membranes of animals Important genera: Staphylococcus Streptococcus Lactococcus Enterococcus
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21 Endospore-forming rods and cocci Gram positive cell wall some important pathogens and industrial organisms Habitat - found in soils; animal intestinal tract Important genera: Bacillus - aerobic or facultative anaerobes Clostridium anaerobic (C. botulinum - food spoilage)
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22 Regular non-spore-forming Gram-positive rods some important pathogens and industrial organisms found in dairy products; genital and oral cavities; animal feces Important genera: Lactobacillus - forms lactic acid from carbohydrates Listeria - animal pathogen
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23 Irregular non-spore-forming Gram-positive rods pleomorphic some important pathogens Habitat: found in soil; human pathogens \ Important genera: Gardnerella Corynebacterium Propionibacterium Actinomyces
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24 Mycobacteria Gram positive, some are important pathogens acid-fast (produce mycolic acids in cell wall) Habitats: found in soil, plants, animals Important genus: Mycobacterium leprosy tuberculosis
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25 Nocardioforms Gram positive cell wall, some pathogens, some are acid-fast Habitats: found in soil and animals form branched filaments, reproduce by fragmentation Important genus: Nocardia pulmomary infections Mycetoma – a destructive infection of hands/feet
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26 Budding or appendaged bacteria Gram negative, contain prosthecae (protrusions such as stalks or buds) Habitat: mostly aquatic Important genera: Hyphomicrobium Caulobacter can grow in low nutrient aquatic environments sometimes attach to a host and use excretions as nutrients
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27 Non-photosynthetic, non-fruiting, gliding bacteria Gram negative cell wall gliding motility Habitat: aquatic Important genera: Cytophaga - degrades cellulose (name means cell eater) Beggiatoa - oxidizes hydrogen sulfide
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28 Gram negative cell wall gliding motility (leaves a slime trail) cells aggregate to form a fruiting body Habitats: soil, dung Important genera: Myxococcus Under proper conditions (low nutrients) spores germinate to form new motile, gliding cells which resemble slime molds Gliding, fruiting bacteria When you’re out of poop, ya gotta slide!
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29 Aerobic, chemoautotrophic bacteria Gram negative cell wall nitrifying and sulfur-oxidizing bacteria agriculturally and environmentally important Habitat: soil Important genera: Nitrosomonas & Nitrobacter reduce nitrogen compounds to nitrates Thiobacillus reduce sulphur compounds to sulfates
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30 Archaea Gram reaction varies not directly related to bacteria no peptidoglycan in cell wall Habitats: found in anaerobic sediments; in extreme environments Important genera: Methanobacterium - useful in sewage treatment Halobacterium (salt loving) Sulfolobus
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31 Anoxygenic, photosynthetic bacteria Gram negative cell wall includes green and purple sulfur and non-sulfur bacteria green and purple sulfur bacteria use H 2 S as an electron donor and release sulfur Habitat: anaerobic sediments Important genera: Chromatium Rhodospirillum Chlorobium
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32 Oxygenic photosynthetic bacteria (Cyanobacteria) Gram negative reaction produce oxygen during photosynthesis many species fix nitrogen Habitat: aquatic Important genera: Chroococcus Anabaena – has plant-like photosynthesis
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33 Actinomycetes Gram positive cell wall branching filaments with reproductive conidiospores (see fig 11.23) many important industrial organisms Habitats: soil, some aquatic Important genera: Streptomyces - important antibiotic producers, also make a gas (geosmin) which contributes to the ‘musty’ odor of soil Frankia - involved in nitrogen fixation with plants Micromonospora – another antibiotic producer
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34 branching filaments with reproductive conidiospores, characteristic of Actinomycetes
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