It resides in the gum pockets, does not have catalase activity, and can be grown outside of an anaerobic chamber. Why do the instructions for the growth of Neisseria gonorrheae recommend a CO 2 -enriched atmosphere? Four tubes are illustrated with cultures grown in a medium that slows oxygen diffusion. Match the culture tube with the correct type of bacteria from the following list: facultative anaerobe, obligate anaerobe, microaerophile, aerotolerant anaerobe, obligate aerobe.
Skip to main content. Microbial Growth. Search for:. Oxygen Requirements for Microbial Growth Learning Objectives Interpret visual data demonstrating minimum, optimum, and maximum oxygen or carbon dioxide requirements for growth Identify and describe different categories of microbes with requirements for growth with or without oxygen: obligate aerobe, obligate anaerobe, facultative anaerobe, aerotolerant anaerobe, microaerophile, and capnophile Give examples of microorganisms for each category of growth requirements.
Figure 2. Diagram of bacterial cell distribution in thioglycolate tubes. Think about It Would you expect the oldest bacterial lineages to be aerobic or anaerobic? Which bacteria grow at the top of a thioglycolate tube, and which grow at the bottom of the tube?
An Unwelcome Anaerobe Figure 4. Think about It What substance is added to a sample to detect catalase? What is the function of the candle in a candle jar? Key Concepts and Summary Aerobic and anaerobic environments can be found in diverse niches throughout nature, including different sites within and on the human body.
Microorganisms vary in their requirements for molecular oxygen. Obligate aerobes depend on aerobic respiration and use oxygen as a terminal electron acceptor. They cannot grow without oxygen. Obligate anaerobes cannot grow in the presence of oxygen. They depend on fermentation and anaerobic respiration using a final electron acceptor other than oxygen. Facultative anaerobes show better growth in the presence of oxygen but will also grow without it.
Although aerotolerant anaerobes do not perform aerobic respiration, they can grow in the presence of oxygen. Most aerotolerant anaerobes test negative for the enzyme catalase. Optimum oxygen concentration for an organism is the oxygen level that promotes the fastest growth rate.
The minimum permissive oxygen concentration and the maximum permissive oxygen concentration are, respectively, the lowest and the highest oxygen levels that the organism will tolerate. Peroxidase , superoxide dismutase , and catalase are the main enzymes involved in the detoxification of the reactive oxygen species.
Superoxide dismutase is usually present in a cell that can tolerate oxygen. All three enzymes are usually detectable in cells that perform aerobic respiration and produce more ROS. A capnophile is an organism that requires a higher than atmospheric concentration of CO 2 to grow.
Multiple Choice An inoculated thioglycolate medium culture tube shows dense growth at the surface and turbidity throughout the rest of the tube. The organisms die in the presence of oxygen The organisms are facultative anaerobes. The organisms should be grown in an anaerobic chamber. The organisms are obligate aerobes. Show Answer Answer b. The organisms are facultative anaerobes. Show Answer Answer a. The organisms are obligate anaerobes.
The bacterium is probably an obligate aerobe. Show Answer Answer d. The bacterium is probably an aerotolerant anaerobe. Show Answer Answer c. It is a capnophile. Matching Four tubes are illustrated with cultures grown in a medium that slows oxygen diffusion.
Show Answer Tube a is an obligate anaerobe. Tube b is an obligate aerobe. Tube c is a microaerophile. Tube d is a facultative anaerobe. Think about It Why are some obligate anaerobes able to grow in tissues e.
Why should Haemophilus influenzae be grown in a candle jar? In terms of oxygen requirements, what type of organism would most likely be responsible for a foodborne illness associated with canned foods?
A microbiology instructor prepares cultures for a gram-staining practical laboratory by inoculating growth medium with a gram-positive coccus nonmotile and a gram-negative rod motile. The goal is to demonstrate staining of a mixed culture. A sample is stained and reveals only gram-negative rods.
Both cultures are known facultative anaerobes. Give a likely reason for success of the gram-negative rod. Assume that the cultures have comparable intrinsic growth rates. Chembiochem 3 , — Ragsdale, S. Pyruvate ferredoxin oxidoreductase and its radical intermediate. Pandelia, M. Evolution and diversification of Group 1 [NiFe] hydrogenases. Is there a phylogenetic marker for O 2 -tolerance? Kubas, A. Mechanism of O 2 diffusion and reduction in FeFe hydrogenases. This paper explores how molecular O 2 attacks iron - only hydrogenases.
Swanson, K. Stripp, S. How oxygen attacks [FeFe] hydrogenases from photosynthetic organisms. Hilton, M. The metabolism of pyrimidines by proteolytic Clostridia. Buckel, W. Enzyme catalyzed radical dehydrations of hydroxy acids. Inactivation-reactivation of aconitase in Escherichia coli. A sensitive measure of superoxide radical. Pan, N. How does oxygen inhibit central metabolism in the obligate anaerobe Bacteroides thetaiotaomicron.
Khademian, M. Do reactive oxygen species or does oxygen itself confer obligate anaerobiosis? The case of Bacteroides thetaiotaomicron. Reddy, S. Dioxygen inactivation of pyruvate formate-lyase: EPR evidence for the formation of protein-based sulfinyl and peroxyl radicals. Biochemistry 37 , — Vita, N.
Disulfide bond-dependent mechanism of protection against oxidative stress in pyruvate-ferredoxin oxidoreductase of anaerobic Desulfovibrio bacteria. Biochemistry 47 , — Pieulle, L. Flint, D. The inactivation of Fe-S cluster containing hydro-lyases by superoxide.
This article presents the first analysis of the mechanism by which oxidants degrade enzymic iron — sulfur clusters. Iron—sulfur proteins with nonredox functions. Jang, S. Micromolar intracellular hydrogen peroxide disrupts metabolism by damaging iron—sulfur enzymes.
Liochev, S. Modulation of the fumarases of Escherichia coli in response to oxidative stress. A conserved motif liganding the [4Fe—4S] cluster in [4Fe—4S] fumarases prevents irreversible inactivation of the enzyme during hydrogen peroxide stress. Redox Biol. Kuo, C. A superoxide-sensitive enzyme.
Superoxide sensitivity of the Escherichia coli 6-phosphogluconate dehydratase. Shimoyama, T. MmcBC in Pelotomaculum thermopropionicum represents a novel group of prokaryotic fumarases. Initial kinetic and mechanistic characterization of Escherichia coli fumarase A. Woods, S. Two biochemically distinct classes of fumarase in Escherichia coli. Acta , 14—26 Sobota, J. Intracellular hydrogen peroxide and superoxide poison 3-deoxy- D -arabinoheptulosonate 7-phosphate synthase, the first committed enzyme in the aromatic biosynthetic pathway of Escherichia coli.
Gu, M. Superoxide poisons mononuclear iron enzymes by causing mismetallation. Li, X. Improved measurements of scant hydrogen peroxide enable experiments that define its threshold of toxicity for Escherichia coli. Mishra, S. An anaerobic bacterium, Bacteroides thetaiotaomicron , uses a consortium of enzymes to scavenge hydrogen peroxide. Korshunov, S. Two sources of endogenous hydrogen peroxide in Escherichia coli. Assay of metabolic superoxide production in Escherichia coli.
Dan Dunn, J. Reactive oxygen species and mitochondria: a nexus of cellular homeostasis. Google Scholar. Meyer, J. Ferredoxins of the third kind. FEBS Lett. Valentine, R. Bacterial ferredoxin. Misra, H. The generation of superoxide radical during the autoxidation of ferredoxins. Rocha, E. The complex oxidative stress response of Bacteroides fragilis : the role of OxyR in control of gene expression. Anaerobe 9 , — Hillmann, F. The role of PerR in O 2 -affected gene expression of Clostridium acetobutylicum.
Partridge, J. Microbiology , — Escherichia coli cytochrome c peroxidase is a respiratory oxidase that enables the use of hydrogen peroxide as a terminal electron acceptor. Pericone, C. Factors contributing to hydrogen peroxide resistance in Streptococcus pneumoniae include pyruvate oxidase SpxB and avoidance of the toxic effects of the Fenton reaction.
Figueiredo, M. Bacterioferritin protects the anaerobe Desulfovibrio vulgaris Hildenborough against oxygen. Anaerobe 18 , — The redox-sensitive transcriptional activator OxyR regulates the peroxide response regulon in the obligate anaerobe Bacteroides fragilis. Raskin, L. Competition and coexistence of sulfate-reducing and methanogenic populations in anaerobic biofilms.
Ferritin-like family proteins in the anaerobe Bacteroides fragilis : when an oxygen storm is coming, take your iron to the shelter. Biometals 26 , — This paper shows that when O 2 is sensed, the anaerobe B. Transcriptomic analysis reveals hub genes and subnetworks related to ROS metabolism in Hylocereus undatus through novel superoxide scavenger trypsin treatment during storage.
BMC Genomics 21 , Andrews, S. Bacterial iron homeostasis. Zeth, K. Dps biomineralizing proteins: multifunctional architects of nature. Lee, J. The PerR transcription factor senses H 2 O 2 by metal-catalysed histidine oxidation. This study reports how the PerR transcription factor uses Fenton chemistry to sense the presence of H 2 O 2.
Marinho, H. Hydrogen peroxide sensing, signaling and regulation of transcription factors. Mukhopadhyay, A. Cell-wide responses to low—oxygen exposure in Desulfovibrio vulgaris Hildenborough. PerR acts as a switch for oxygen tolerance in the strict anaerobe Clostridium acetobutylicum. This study demonstrates that the activation of a peroxide defence system enables some growth of an obligate anaerobe in the presence of O 2.
The role of O 2. Tulstrup, M. Antibiotic treatment affects intestinal permeability and gut microbial composition in wistar rats dependent on antibiotic class. Rigottier-Gois, L.
Dysbiosis in inflammatory bowel diseases: the oxygen hypothesis. ISME J. Winter, S. Gut inflammation provides a respiratory electron acceptor for Salmonella. Keyer, K. Inactivation of dehydratase [4Fe—4S] clusters and disruption of iron homeostasis upon cell exposure to peroxynitrite. Hydrogen peroxide inactivates the Escherichia coli Isc iron—sulphur assembly system, and OxyR induces the Suf system to compensate.
Evolutionary adaptations that enable enzymes to tolerate oxidative stress. Bowman, S. Solution structure and biochemical characterization of a spare part protein that restores activity to an oxygen-damaged glycyl radical enzyme.
This structural analysis shows how a complementary protein can reactivate O 2 - damaged PFL. Savageau, M. Escherichia coli habitats, cell types, and molecular mechanisms of gene control.
If you mix the bacteria with a lethal agent you get a progressive reduction in the number of survivors. Lysol, phenol carbolic acid , coal tar distillates Ichthamol , hexachlorophene. All are powerful disinfectants. Also a dehydration effect denatures proteins. Good for washing skin. Kills vegetative bacterial cells and enveloped viruses well. Not effective on endospores and non-enveloped viruses. Silver sulfadiazine is also used on burn patients. Used in paint and used to treat swimming pools and fish tanks.
Toxic to invertebrates. Chlorine widely used as a disinfectant to treat water and in dairy industry. Two to four drops of chlorox per liter of water will disinfect the water after 30 min. Iodine is used as a skin disinfectant.
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