November 18 Flashcards
Type 1 Methanotroph
Gamma
disc-shaped vesicles
internal membranes arranged
Lack complete citric acid/ Kreb’s cycle
Obligate methylotroph
No Kreb’s cycle to produce NADH
Type II Methanotroph
Alpha
Paired membrane on edge of cell
Not Obligate
Methanotroph Ecology
Fixation of CH4 to CO2 or to cell parts
Widespread
Symbiotic relationships
Certain marine mussels–near hydrocarbon seeps, happen in the Gulf of Mexico–found in gill tissue
Aerobic/ Facultative Aerobic Chemoorganotrophs
Examples
Pseudomonads
Zymomonas
Acetic Acid Bateria
Nitrogen-fixing Bacteria
Pseudomonads
Straight or curved rods
Polar flagella
Obligate aerobes
Nutritionally diverse
Numerous in soil and water
Ecologically important: break down many nutrients and xenobiotic compounds (bioremediation)
Some are pathogenic, some are plant pathogens that damage leaves (agricultural pathogens)
Pseudomonas aeroginosa
Pseudomonas aeroginosa
Nosiconial infections, biofilms in tubing
Thrives in quats: colorless tasteless, safe for human consumption antiseptic
Zymomonas
Large gram negative rod
Vigorously ferments sugars to EtOH
Used to produce pulque (fermenting agave sap, sap is harvested then it is seeded with Zymomonas to make a white beverage)
Beer spoilage organism
Acetic Acid Bacteria
Complete oxidation of alcohols and sugars
End products: lots of organic acids
Motile rods, aerobic, acid tolerant
Acetobacter aceti: used to produce vinegar add to alcoholic beverage oxidizes alcohols to acids, contaminant in wines, produces cellulose which is used in pellicle formation which keeps them near oxygen
Nitrogen-Fixing Bacteria
Free-living aerobic
soil microbes
fix atmospheric oxygen nonsymbiotically
Azobacterm, Azospirillium
Nitrogenase: enzyme need to fix N2, will not function in the presence of O2 rely on capsules and slime layers to protect
Rhizobium
Symbiotic N fixer, nodules on legume, roots protect nitrogenase using leghemoglobin which binds to O2 and protects nitrogenase
Enteric Bacteria Examples
Escherichia, Salmonella, Shigella, Proteus
Enteric Bacteria
Gamma
Facultative aerobes
Motile and nonmotile
nonendospore forming
ferment lots of sugars, usually grouped by products made through anaerobic fermentation (MR-VP: mixed acid fermenters or butanediol fermenters)
Escherichia
Found in GI tract of endotherms (including humans)
Usually not problematic
Synthesize numberous vitamins (needed for many haloenzymes)
Essential part of our microbiome
Can be pathogenic (UTIs) ascending infections
Some such as E. coli 0157:H7 cause HUS- hemolytic uremic syndrome which destroys renal cells
Salmonella and Shigella
Closely related to Escherichia
Usually pathogenic
Poultry, reptiles
Salmonella: best way to id is using immunoassays to look for specific antibodies produced for specific surface antigens on Salmonella
Proteus
Very motile
Swarm on agar
Cause UTIs, associated with long term urinary catheter use
Vibrios
Motile
Straight or curved rods
facultative aerobes
Best known: Vibrio, Alivibrio, Photobacterium
Usually aquatic
Some pathogens
Photobacterium is bioilluminescent
