Lab Quiz 6: Anaerobes, Environmental Conditions, and Antimicrobial Conditions (Bio 286 - Microbiology) Flashcards
psychrophiles
microbes that grow optimally under cool conditions (0-15 degrees Celsius)
psychrotrophs
microbes that tolerate cool conditions but grow best around room temperature (20 degrees Celsius)
mesophiles
microbes that grow best between room temperature and body temperature (20-40 degrees Celsius)
thermophiles
microbes with optimal growth under high temperatures (>40 degrees Celsius)
acidophiles
microbes that grow best at low pH (1-5)
neutrophiles
microbes that grow best at neutral pH (6-8)
alkalinophiles
microbes that grow best at alkaline or high pH (9-14)
nonhalotolerant
microbes that are inhibited by moderate levels of salt (1-5% NaCl)
halotolerant
microbes that can tolerate higher concentrations of salt (1-15% NaCl)
halophiles
microbes requiring elevated salt concentrations for growth
halophiles cannot grow without
added salt (whereas halotolerant microbes can grow without added salt)
mesophile microbes
Alcaligenes faecalis, Escherichia coli, Saccharomyces cerevisiae, and Staphylococcus aureus
thermophile microbe
Bacillus stearothermophilus
psychrophile microbe
Pseudomonas fluorescens
alkalinophile microbe
Alcaligenes faecalis
neutrophile microbes
Bacillus stearothermophilus, Escherichia coli, Pseudomonas fluorescens, and Staphylococcus aureus
acidophile microbe
Saccharomyces cerevisiae
halotolerant microbes
Alcaligenes faecalis, Bacillus stearothermophilus, Escherichia coli, Pseudomonas fluorescens, and Staphylococcus aureus, and Saccharomyces cerevisiae
obligate aerobes
organisms that require oxygen to live
obligate anaerobes
organisms that are unable to use molecular oxygen to obtain energy and are usually killed or inhibited by its presence
facultative anaerobes
organisms that can use oxygen if it is available but can also grow when oxygen is absent
aerotolerant anaerobes
organisms that cannot use oxygen for growth but they can tolerate its presence well
microaerophilic
organisms that require a lower oxygen concentration than what is in the air
thioglycolate broth
contains sodium thioglycolate and cysteine that act as reducing agents to create anaerobic conditions when they convert molecular oxygen to water; resazurin is used as the color indicator– where strict aerobes will grow only it the pink band, microaerophiles growing near the bottom of the band (in lower concentrations of oxygen), and anaerobes growing in areas without pink (indicating absence of oxygen)
oxygen indicators
resaxurin is pink when oxidized and colorless when reduced and methylene blue is blue when oxidized and colorless when reduced
anaerobic jar
chamber from which oxygen is removed to be replaced with a carbon dioxide atmosphere
brewers anaerobic agar plates
contain methylene blue as oxygen indicator; culture anaerobes when placed inside an anaerobe jar
anaerobic microbe
clostridium sporogenes
aerobic microbe
Pseudomonas aeruginosa
aerotolerant microbe
Enterococcus faecalis
facultative anaerobic microbe
Escherichia coli
disinfectants
compounds used to kill/inhibit microbes on inanimate objects, tend to be more toxic
disinfectant classes
phenols, quaternary ammonium compounds, oxidizer, and alkylator
disinfectant phenol
lysol
disinfectant quaternary ammonium compound
roccal
disinfectant oxidizer
bleach
disinfectant alkylator
aldehyde
antiseptics
compounds used to kill/inhibit microbes on living surfaces (skin tissue), tend to be less toxic
antiseptic classes
alcohol, oxidizer, surfactant, phenolic
antiseptic alcohol
isopropanol
antiseptic oxidizer
iodine
antiseptic surfactant
dish soap
antiseptic phenol
germicidal soap
antibiotics
compounds that are produced by other microorganisms and tend to be used chemotherapeutically to inhibit/kill microbes
antibiotics that target peptidoglycan
ampicillin, cephalothin, penicillin
antibiotics that target 70S ribosome
erythromycin, streptomycin, and tetracycline
disk diffusion method
apply the antibiotic compounds using paper disk and allow the chemical to diffuse into the media to create a chemical gradient
minimum inhibitory concentration (MIC)
threshold concentration necessary to kill or inhibit microbial growth; least amount of drug needed to block visible growth
zone of inhibition
Region around a chemical saturated disc, where bacteria are unable to grow due to adverse effects of the compound in the disc.
resistant microbes have
smaller zone of inhibition; larger MIC
susceptible microbes have
larger zone of inhibition; smaller MIC
best antiseptic
iodine (oxidizer)
best disinfectant
aldehyde (alkylator)
most resistant microbe
candida albicans (because it is a yeast – its cell wall is made of chitin and its ribosomes are 80S – so now antibiotics can target it)
most resistant bacteria
Pseudomonas aeruginosa
most susceptible bacteria
staphylococcus aureus (only has one membrane because it is gram positive – so antibiotics can get through cell quicker/more easily than they can for gram negative cells)
