Lecture 12 Flashcards
What are the different anaerobes?
Chemolithotrophs
Chemoorganotrophs with respiratory chain
Chemoorganotrophs with fermentation
Phototrophic anaerobes (anoxygenic photosynthesis)
What are the different aerobes?
Chemolithotrophs
Chemoorganotrophs - obligate aerobes
Chemoorganotrophs - facultative anaerobes
Photosynthetic aerobes (oxygenic photosynthesi)
What is the difference between sulfate reducing bacteria and sulfur oxidizing bacteria?
Sulfate reducing bacteria use sulfate (SO4) as electron acceptor or S to produce H2S
Sulfur oxidizing bacteria use S, H2S as electron donor to produce sulfate (SO4)
What is the importance of Clostridium, Lactic Acid Bacteria, and Propionibacterium in industrial and food-processing fermentation reactions
They use fermentation which can be used to make ABE (solvents), cheeses, and other food products
What are the 4 types of photosynthetic anaerobes?
Purple sulfur
Purple non sulfur
Green sulfur
Green non-sulfur
How do mixotrophs use dual metabolic schemes to grow under different conditions?
Anaerobic phototrophs in light, and aerobic chemotrophs in dark (photosynthesis vs respiratory chain)
How can bacteria extract precious metals from ores?
Sulfur oxidizers use sulfur in sulfur compounds (Au2S3) for metabolism. Free up Au
Sketch the nitrogen cycle.
Be able to place on your drawing the following organisms:
nitrogen-fixing bacteria, nitrifying bacteria, denitrifying bacteria, and the following reaction
products: N2, NH4+, NO3-, NO2
Nitrogen fixing bacteria convert N2 to NH4+
Nitrifying bacteria convert NH4+ to NO2-
Nitrifying bacteria convert NO2- to NO3-
Denitrifying bacteria convert NO3- to N2
What ways can nitrogen-fixing bacteria protect nitrogenase from oxygen damage
- use oxygen as terminal electron acceptor for respiration
- form a stable complex with ferredoxin
What are 2 genera of nitrogen-fixing bacteria
Nitrogen-fixing bacteria in root nodules of legumes and the ones in soil
Why does Pseudomonas occupy many metabolic niches in multiple environments
it is better to have diversity because it lets them be adaptable
How does Deinococcus withstand very high levels of radiation?
It has supercharged DNA repair enzymes shielded by Mn+2- phosphate-peptide complex
Endospore vs cyst
Endospores allow long-term survival in harsh environments
Cysts have a thick cell wall that are less durable
Unique metabolic niche of Myxobacteria
aggregate into fruiting bodies
Unique metabolic niche of Streptomyces
produce many antibiotics as secondary metabolites, also has conidial spores
