Chapter 11 Microbiology Objectives and Vocabulary
anoxygenic phototrophs
Photosynthetic organisms that do not produce oxygen
To the extent discussed in class compare and contrast the characteristics of the purple bacteria and green bacteria.
Purple bacteria- Gram negative bu appear purplish, all in cytoplasmic membrane Green bacteria- gram negative organisms, green/brownish in color
Describe the examples of how bacteria that thrive in aquatic environments obtain and store nutrients.
They can consume others to get nutrients, Sheathed bacteria from tubes of cells can help each other gain nutrients in a dilute environment, prosthecate bacteria provided an increased surface area to facilitate the absorption of nutrients.
oxygenic phototrophs
photosynthetic organisms use water as a source of electrons for reducing power
anoxic
without oxygen
Describe the representative obligate aerobes and facultative anaerobes discussed in class.
Obligate aerobes- must have oxygen a. Micrococcus- common lab contaminant, gram-positive b. Mycobacterium- waxy cell wall that resists staining acid C.Pseudomonas- common environmental bacteria that as a group, can degrade a wide variety of chemicals and it is gram negative Facultative anaerobes- prefer oxygen, but can work without it a. Corynebacterium- widespread in nature, gram-positive b. Enteric- Most reside in the intestinal tract those that ferment lactose are coliforms c. Vibrio sp.- typically found in marine environments because most species require at least low levels of sodium for growth
Chemotrophs
Organisms that get energy from chemicals
Chemolithotrophs
Organisms that harvest energy by oxidizing inorganic chemicals
To the extend discussed in class compare and contrast Agrobacterium species and rhizobia.
Agrobacterium species- gram negative rod shaped bacteria, have a competitive advantage in soil, can cause plant tumors and does this by Creating Ti plasmids which transfer a part of a plasmid to a plant cell Rhizobia- Gram negative rod shaped bacteria that fix nitrogen and form intimate relationships with legumes
Compare and contrast the examples of bacteria that use animals as habitats.
Bacteria that inhabit the skin- s. aureus: skin and wound infections, food poisoning and s. saphroyticus Bacterias that inhabit mucous membranes- Streptococcus, Corynebacterium, Lactobacillus (vaginal), and Clostridium, enterobacteriache
Describe the characteristics of cyanobacteria
Cyanobacteria- Gram negative, live in variety of environments such as freshwater, soils, and surfaces of rocks, can use nitrogen fixation
Compare and contrast the characteristics and habitats of the extreme halophiles and extreme thermophiles.
Extreme halophiles- found in salty environments such as salt lakes, soda lakes, and brines used for curing fish, most grow in well saturated salt solutions, require a minimum of 9% NaCl, aerobic or facultatively anaerobic, Extreme thermophiles- found near volcanic vents, found in hydrothermal vents in the deep sea and hot springs
Describe the family Enterobacteriaceae, and explain what distinguishes coliforms from other members of this family.
Found in the intestinal tract of organisms, some thrive in rich soil. They are facultative anaerobes Enteric bacteria that can ferment lactose are called coliforms.
To the extent discussed in class compare and contrast the characteristics and habitats of methanogens, sulfur‐ and sulfate‐reducing bacteria, Clostridium species, lactic acid bacteria, and Propionibacterium species.
Methanogens- Obtain energy/ generate ATP by oxidizing hydrogen gas, found in anaerobic environments, usually found in swamps sulfur and sulfate reducing bacteria- Live in mud with organic material, sulfur smell, H2S reacts with metals Clostridium species- Gram positive, can form endospores, soil inhabitants, live in anaerobic Lactic Acid Bacteria- Gram positive, can grow in aerobic environments, but most use fermentation Propionibacterium- Gram positive, produce propionic acid as their main fermentation end product, can ferment lactic acid, valuable to dairy industry
Describe the bacterial groups, discussed in class, that form resting stages.
Myxobacteria- resting stage Gram negative and positive, creates fruiting body, cell secretes a slime layer
nitrogen fixation
conversion of nitrogen gas to ammonia
Primary producers
harvest energy of sunlight
Chemoorganotrophs
oxidize organic compounds such as glucose to obtain energy
Compare and contrast the characteristics of sulfur‐oxidizing bacteria, nitrifiers, and hydrogen‐oxidizing bacteria.
sulfur oxidizing bacteria- gram negative bacteria that obtain energy by oxidizing elemental sulfur and reduced sulfur compounds Nitrifiers- gram negative bacteria that obtain energy by oxidizing inorganic nitrogen compounds, bacteria is a concern to farmers who fertilize their crops, can oxidize ammonium to form nitrate Hydrogen oxidizing bacteria- thermophilic, live in hot springs, maximum growth temp at 95 degrees celsius, gram negative
