| Aerotolerant anaerobe | - organsim that doesn't use oxygen in metabolic rxns but can grow in its presence - an anaerobe that tolerates air (21% oxygen) - can detoify or excrete toxic oxygen products - some Lactobacillus spp, Enterococcus faecalis, Enterococcus faecium |
| Aerotolerant anaerobe | - organsim that doesn't use oxygen in metabolic rxns but can grow in its presence - an anaerobe that tolerates air (21% oxygen) - can detoify or excrete toxic oxygen products - some Lactobacillus spp, Enterococcus faecalis, Enterococcus faecium |
| Aerotolerant anaerobe | - organsim that doesn't use oxygen in metabolic rxns but can grow in its presence - an anaerobe that tolerates air (21% oxygen) - can detoify or excrete toxic oxygen products - some Lactobacillus spp, Enterococcus faecalis, Enterococcus faecium |
| Aerotolerant anaerobe | - organsim that doesn't use oxygen in metabolic rxns but can grow in its presence - an anaerobe that tolerates air (21% oxygen) - can detoify or excrete toxic oxygen products - some Lactobacillus spp, Enterococcus faecalis, Enterococcus faecium |
| Aerotolerant anaerobe | - organsim that doesn't use oxygen in metabolic rxns but can grow in its presence - an anaerobe that tolerates air (21% oxygen) - can detoify or excrete toxic oxygen products - some Lactobacillus spp, Enterococcus faecalis, Enterococcus faecium |
| Aerotolerant anaerobe | - organsim that doesn't use oxygen in metabolic rxns but can grow in its presence - an anaerobe that tolerates air (21% oxygen) - can detoify or excrete toxic oxygen products - some Lactobacillus spp, Enterococcus faecalis, Enterococcus faecium |
| Psychrophile (T) | - organism that can grow at 0 C, optimum 15 C or lower, max 20 C
- commonly isolated from Arctic and Antarctic environments
- enzymes, transport systems, and protein synthesis mechanisms of psychrophiles work well at cold temperatures
- cytoplasmic membrane remains fluid at cold temps due to high levels of unsaturated fatty acids
- many psychrophiles suffer from membrane disruption & leak cytoplasmic constituents |
| Psychrotroph (T) | - an organism that can grow from from 0-7 C, optimum temperature between 20-30 C- maximum growth temperature 35 C- major spoilage organisms of refrigerated foods- Pseudomonas spp. |
| Mesophile (T) | - an organism that grows optimally between 30-40 C
- minimum growth at 15-20 C, maximum is 45 C
- many human enteric pathogens that grow rapidly at human body temp
- ex: Salmonella, Escheria coli, Shigella dysenteriae |
| Thermophile (T) | - an organism that can grow at 55 C or higher, optimum temp between 55 - 65 C
- minimum temp 45 C
- ex: Bacillus stearothermophilus |
| Metabolism | - sum total of all chemical rxns in living cells
- catabolism and anabolism |
| Catabolism | - break down
- energy (ATP) generated by breaking bonds (stripping electrons from large molecules)
- e- pass along an electron transport chain (ETC) in cytoplasmic membrane
- ATP produced by special enzymes (ATPases) located in cytoplasmic membrane
- some energy stored as ATP, remainder given off as heat |
| Anabolism | - build up
- microorganisms use simple molecules and ATP to synthesize complex molecules
- ex: protein, DNA |
| ETC in microbes | - if electron transport stops, microbial cell will stop growing and eventually die bc of its inability to make energy (ATP)
- microorganisms must use a terminal e- acceptor at end of chain to remove electrons and maintain electron transport |
| TEA | - terminal electron acceptor
- aerobes: oxygen
- anaerobes: nitrite, nitrate, sulfate |
| Aerobe | - organism that uses oxygen in metabolic reactions - requires oxygen for growth - Pseudomonas spp. |
| Strict aerobe | - grows only in the presence of air (21% oxygen) - Alteromonas putrefaciens |
| Anaerobe | - cannot grow in the presence of air - can't use oxygen in metabolic reactions - oxygen is toxic - Clostridium botulinum, Bifidobacterium spp. |
| Microaerophile | - requires a small amout of oxygen (5%) for growth - larger amounts of oxygen are toxic to this organism - anaerobic environment inhibits growth - Campylobacter jejuni |
| Facultative anaerobe | - oxygen not req. but may use it if available - metabolically versatile organsim - can use oxygen or other compounds as a TEA - Salmonella spp, Listeria monocytogenes, Escherichia coli, Shigella spp, Vibrio spp |
| Aerotolerant anaerobe | - organsim that doesn't use oxygen in metabolic rxns but can grow in its presence - an anaerobe that tolerates air (21% oxygen) - can detoify or excrete toxic oxygen products - some Lactobacillus spp, Enterococcus faecalis, Enterococcus faecium |
