Chapter 11 - Prokaryotic Organisms

1. Sulfur and sulfate-reducing bacteria use sulfur as terminal electron acceptors and oxidize organic material 1.1) Reduce it to hydrogen sulfide -> Responsible for rotten egg smell 1.2) These organisms essential for sulfur cycle in ecosystem 2) Generally found in mud rich in organic matter and sulfur

1. oxidize reduced inorganic chemicals to produce energy 2) Use alternate terminal electron acceptor other than oxygen -> Usually carbon dioxide or sulfur 3) Usually members of the domain Archaea 4) Some anaerobic chemoorganitrophs produce ATP via anaerobic respiration through the oxidation of organic molecules -> Also use terminal electron acceptor other than oxygen -> Sulfur and sulfate are common 5) Other anaerobic chemoorganitrophs produce energy through fermentation -> Produce energy through substrate phosphorylation only

1. Members of Domain Archaea 2) Produce energy by reducing hydrogen and using carbon dioxide as terminal electron acceptor -> This process creates methane and water 3) Commonly found in sewage, swamps, marine sediments and digestive tract of mammals 4) Highly sensitive to oxygen -> Anaerobic chambers used for cultivation

1. Members of genus Clostridium are Gram-positive rods. Obligate anaerobes (obligate fermenters) 1.1) Produce endospores 1.2) Common inhabitant of soil 2) Organisms in this genus ferment wide variety of compounds to produce energy 2.1) Some organisms ferment amino acids in process of putrefaction 3) Clostridium tetani - tetanus, Clostridium perfringens - gas gangrene, Clostridium botulinum - botulism, pseudomembranous colitis

1. are Gram-positive organisms that produce lactic acid as an end product of fermentation -> Includes Streptococcus, Enterococcus, Lactococcus, Lactobacillus, Leuconostoc 2) Most organisms of this group can grow in aerobic environments but are obligate fermenters

1. are Gram-positive rods 2) Organisms produce propionic acid as end product of fermentation 2.1) Essential in the production of Swiss cheese 2.2) These organisms can also ferment lactic acid 3) Can extract residual energy from waste product of other organisms

Obligate aerobes obtain energy using aerobic respiration exclusively -> None use fermentation

1. Gram-positive cocci found in soil and dust 2) Produce yellow pigmented colonies

Gram-positive bacterium, live on dead and decaying matter

Gram-negative rods, Motile and often pigmented, Common opportunistic pathogen

1. Both have scientific and commercial uses 1.1) Thermus produces Taq polymerase 1.2) Dinococcus used to clean up radioactive contamination

Can live with our without oxygen, preferentially use aerobic respiration. -> Can use fermentation as alternative in absence of oxygen

Gram-positive pleomorphic rods, Inhabits soil, water and surface of plants

1. Gram negative rods 2) Facultative anaerobes that ferment glucose. 3) Motility = peritrichous flagella 4) Enterics reside in the intestinal tracts of humans & animals as part of the normal flora. 5) Some thrive in rich soil. 6) Entero = intestine (small intestine). 7) Colo = colon, large intestine. 8) Coliforms = Enterics that ferment lactose (p.787). 9) Coliforms used as indicator of fecal pollution & potential fecal-borne pathogens.

Escherichia - gastroenteritis, Enterobacter, Erwinia, Klebsiella - Pneumonia, Proteus - UTI (urinary tract infection), Salmonella - typhoid fever, Shigella - shigellosis / dysentery, Yersinia - bubonic / pneumonic plague

resting or dormant type of cell that is highly resistant to environmental extremes (heat, dessication, oxygen, radiation, disinfectants).

1. Obligate aerobes + facultative anaerobes 2) Gram + rods 3) Bacillus anthracis - anthrax

1. Gram + bacteria, resemble fungi, obligate aerobes. 2) Mycelium = mass of branching filaments 3) Hyphae = filaments Conidia = dormant spores 4) Produce extracellular enzymes that degrade organic compounds. 5) Geosmin = "earthy odor" 6) Naturally produce antibiotics: streptomycin, tetracycline, & erythromycin.

produce plant tumors to gain nutrient -> These tumors are often fatal to plant

have a mutually beneficial relationship with plants -> Organisms fix nitrogen that is used for a nutrient source for the plant

1. Numerous genera that inhabit soil can form resting stages that enable survival in dry periods 2) Endospores, cysts, fruiting bodies, and mycelium are examples of resting stage structures 2.1) Bacillus and Clostridium species produce endospores 2.2) Azobactor species produce cysts 2.3) Myxobacteria species form fruiting bodies 2.4) Streptomyces species form mycelium 3) Endospores tend to be more resistant to environmental insult than cysts or fruiting bodies 4) Organisms produce numerous mechanisms for nutrient acquisition and retention 4.1) Clustering within a sheath -> Bacteria form chains encased in tubes which enables them to find favorable habitat -> Includes genera Sphaerotilus and Leptothrix 4.2) Derive nutrient from other organisms 4.2.1) Bdellovibrio prey on other organisms 4.2.2) Bioluminescent bacteria establish relationships with other animals for food and protection 4.2.3) Legionella live inside protected confines of protozoa

1. Gram negative , obligate aerobes 2) Utilize amino acids, but not carbohydrates as a source of carbon and energy. 3) Often live intracellularly within protozoa & macrophages. 4) Isolated from water in air conditioners & produce misters 5) Legionella pneumophila - Legionnaire's disease

Organisms produce numerous mechanisms for nutrient acquisition and retention 1) Move by unusual means 1.1) Spirochetes move via axial filaments in corkscrew motion 1.2) Magnetotactic bacteria move by means of magnetic crystals aligning them with earth's magnetism 2) Formation of storage graduals 2.1) Spirillum species form volutin granules to store phosphate 2.2) Certain marine bacteria store sulfur and nitrate for oxidation and reduction -> Gives advantage to bacteria in certain environments

1. Spira = coil, chaete = hair 2) Gram negative, helical flexible cells 3) Unique motility enables movement through thick viscous environments (mud). 4) Flexible cell wall with "corkscrew" motility via axial filament contained within periplasm (endoflagella). 5) Difficult or impossible to cultivate. 6) Free-living aquatic; reside on or in animals. 7) Spirochaeta = anaerobes or facultative anaerobes 8) Leptospira = aerobic

Bodies of animals provide wide variety of ecological habitats for bacteria. 1) Skin inhabited by Staphylococcal species -> Significant component of skin flora 2) Mucous membranes are inhabited by numerous genera including Bacteriods, Bifidobacterium, Campylobacter and Helicobacter, Neisseria and Treponema 3) Bacteria that are obligate intracellular parasites including Rickettsia, Orientia and Ehrlichia reside in blood-sucking arthropods -> Mainly ticks or lice 4) Coxiella transmitted person to person without arthropod vector

1. Gram + cocci, facultative anaerobes, catalase 2) Most Staph reside harmlessly as normal flora of skin. 3) Staphylococcus epidermidis 4) Staphylococcus aureus - skin / wound infections, food poisoning 5) Staphylococcus saprophyticus - UTI

1. Gram + pleomorphic rods; Diphtheroids 2) Aerotolerant anaerobes, i.e, obligate fermenters - only produce ATP via SLP. 3) Inhabit anaerobic microenvironments of the skin (hair follicles). 4) Produce propionic acid as 1^ fermentation end product. 5) Ferment lactic acid; extract residual energy from a waste product of other bacteria. 6) Propionibacterium acnes - Acne (p. 523)

1. Mucous membranes of the respiratory, genitourinary, and intestinal tracts provide a habitat for numerous bacteria. 2) Streptococcus, Corynebacterium - respiratory tract 3) Lactobacillus - vagina 4) Clostridium, Enterics - intestinal tract

1. Gram negative rods & coccobacilli 2) Obligate anaerobes 3) Inhabit mouth, GI tract, & genital tract of humans and animals. 4) Bacteroides fragilis = ~ 30% of bacteria in human feces. 5) Responsible for abscesses / septicemia 2^ (secondary to) abdominal surgery.

1. Gram + irregular rods 2) Anaerobes 3) Reside primarily in intestinal tract of humans / animals. 4) Predominant intestinal flora of breast fed infants, & provide protective function by excluding pathogens. 5) Formula-fed infants colonized with lower concentrations

1. Gram negative curved rods 2) Microaerophiles 3) Campylobacter jejuni = diarrhea 4) Resides in GI tract of poultry, & causes diarrheal disease in humans. 5) Helicobacter pylori = gastric / duodenal ulcers 6) Inhabits the stomach & survives due to its production of the enzyme urease. 7) Urease - breaks down urea to produce ammonia, which neutralizes stomach acid in the immediate environment.

breaks down urea to produce ammonia, which neutralizes stomach acid in the immediate environment

1. Gram negative coccobacilli 2) Common flora of respiratory tract. 3) "blood loving" 4) Require hematin & NAD found in blood. 5) Haemophilus influenzae = respiratory infections, ear infections, meningitis in children 6) Haemophilus ducreyi - STD chancroid

1. Gram negative diplococcic 2) Kidney-bean shaped cocci that occur in pairs. 3) Obligate aerobes 4) Common inhabitants of animal / human mucous membranes. 5) Nutritionally fastidious 6) Neisseria gonorrhoeae - gonorrhea 7) Neisseria meningitidis - meningitis

1. 1Lack a cell wall 2) Sterols in cell membrane provide strength & rigidity. 3) Smallest forms of life with minimum sized genome. 4) Colonies = "fried egg" appearance 5) Mycoplasma pneumoniae - atypical pneumonia or "walking pneumonia". (p. 590)

1. Spirochetes that inhabit body fluids and mucous membranes of humans & animals. 2) Gram negative cell wall 3) - obligate anaerobes or microaerophiles that inhabit mouth and genital tract. 4) Treponema pallidum - syphilis 5) Lacks critical enzymes of TCA cycle.

1. microaerohiles 2) Transmitted by arthropods such as ticks & lice. 3) Genome composed of linear chromosome. 4) Relapsing fever & Lyme disease.

1. Gram negative rods or coccobacilli 2) Unable to reproduce outside of a host cell. 3) Lost ability to synthesize needed for extracellular growth. 4) Transmitted when a blood-sucking arthropod (tick or louse) takes a blood meal from a human. 5) Rickettsia rickettsii - Rocky Mountain Spotted Fever 6) Rickettsia prowazekii - epidemic typhus 7) Coxiella burnetii - Q fever 8) Survives outside host & does not require an arthropod for transmission.

1. Gram negative cell wall appearance, although lacks peptidoglycan. 2) Transmitted directly from person to person; not through bite of blood-sucking arthropod. 3) Reticulate bodies = non-infectious form 4) Elementary bodies = infectious form released upon cell death. 5) Chlamydia trachomatis - NGU & eye infections 6) Chlamydia pneumoniae - atypical pneumonia 7) Chlamydia psittaci - psittacosis (pneumonia)

are found in high salt environments 1) Salt lakes, soda lakes and brines -> Most require 9% salt concentration 2) Includes genera Halobacterium, Halorubrum, Natronobacterium and Natronococcus

are found in regions of volcanic and thermal vents as well as sulfurous fissures and hot springs 1) Methanothermus grows at temperatures as high as 97°C 2) Pyrolobus fumarii grows between 90°C and 113°C 3) Sulfolobus species grow only above 50°C -> Also require pH between 1 and 6

grow at extremely high temperatures and low pH

Grow optimally at pH of 2 -> Some species lyse at neutral pH

Optimal growth below pH 1

oxidize organic molecules with high potential energy (sugars), ATP made by cellular respiration or via fermentation pathways with sugars as e- donor