biology

Shewanella putrefaciens

Shewanella putrefaciens is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Shewanella putrefaciens rather than just read about it. In short: Shewanella putrefaciens is a Gram-negative pleomorphic bacterium. It has been isolated from marine environments, as well as from anaerobic sandstone in the Morrison Formation in New Mexico.

Key takeaways

Shewanella putrefaciens belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Shewanella putrefaciens to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Shewanella putrefaciens from memory before moving on to harder problems.

Reference excerpt

Shewanella putrefaciens is a Gram-negative pleomorphic bacterium. It has been isolated from marine environments, as well as from anaerobic sandstone in the Morrison Formation in New Mexico. S. putrefaciens is also a facultative anaerobe with the ability to reduce iron and manganese metabolically; that is, it can use iron and manganese as the terminal electron acceptor in the electron transport chain (in contrast to obligate aerobes which must use oxygen for this purpose). It is also one of the organisms associated with the odor of rotting fish, as it is a marine organism which produces trimethylamine (hence the species name putrefaciens, from putrid). In both solid and liquid media, S. putrefaciens is often recognizable by its bright pink color. On solid media, the colonies are round, fast-growing, and pink. The organism is also fast-growing in liquid media, and there will give the liquid an overall pink hue. On blood agar plates, the colonies are typically convex and large, with a brown pigment, and cause “greening” of the agar around the colonies. S. putrefaciens are non-lactose fermenters on MacConkey agar. As with all Shewanella, this organism produces hydrogen sulfide on TSI. Although it is very rare for it to act as a human pathogen, there have been cases of infections and bacteremia caused by S. putrefaciens. Shewanella putrefaciens is one of several species that have been shown to derive energy by reducing U(VI) to U(IV), which is thought to be important in making uranium deposits. In fact, strain CN32 is very metabolically versatile and is capable of reducing metals, metalloids, and even radionuclides in place of oxygen during anaerobic growth. This is known to include (but is not necessarily limited to) Fe(III)→Fe(II), Mn(IV)→(via Mn(III) intermediate)→Mn(II), V(V)→V(IV), Tc(VII)→Tc(V/IV) and U(VI)→U(IV).

See also Geobacter metallireducens Paraburkholderia fungorum

References

External links Martín-Gil, J.; Ramos-Sánchez, M.C.; Martín-Gil, F.J. (October 2004). "Shewanella putrefaciens in a fuel-in-water emulsion from the Prestige oil spill". Antonie van Leeuwenhoek. 86 (3): 283–285. doi:10.1023/B:ANTO.0000047939.49597.eb. S2CID 739231. Type strain of Shewanella putrefaciens at BacDive - the Bacterial Diversity Metadatabase

Worked examples

Example 1 — a first encounter with Shewanella putrefaciens

Start with the simplest possible case. Write down what Shewanella putrefaciens claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Shewanella putrefaciens before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Shewanella putrefaciens ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Shewanella putrefaciens

In research: Shewanella putrefaciens appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Shewanella putrefaciens in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Shewanella putrefaciens is common in secondary-school and first-year university syllabi. It links to neighbouring topics Alteromonadales, Alteromonadales stubs, Bacteria described in 1986, so understanding it makes those chapters shorter.
In everyday life: Look for Shewanella putrefaciens outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Shewanella putrefaciens in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Shewanella putrefaciens means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Shewanella putrefaciens out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Shewanella putrefaciens in simple terms?

Shewanella putrefaciens is a Gram-negative pleomorphic bacterium. It has been isolated from marine environments, as well as from anaerobic sandstone in the Morrison Formation in New Mexico.

Why does Shewanella putrefaciens matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Shewanella putrefaciens?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Shewanella putrefaciens.