biology

Holdemanella

Holdemanella 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 Holdemanella rather than just read about it. In short: Holdemanella is a genus of Gram-positive, strictly anaerobic bacteria in the family Erysipelotrichaceae. Members of this genus are non-spore-forming, rod-shaped fermenters that produce short-chain fatty acids such as butyrate.

Key takeaways

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

Reference excerpt

Holdemanella is a genus of Gram-positive, strictly anaerobic bacteria in the family Erysipelotrichaceae. Members of this genus are non-spore-forming, rod-shaped fermenters that produce short-chain fatty acids such as butyrate. They are commonly found in the intestinal tracts of mammals and are implicated in host metabolic health.

Taxonomy The genus Holdemanella was established by De Maesschalck et al. in 2014 to reclassify Eubacterium biforme as Holdemanella biformis based on 16S rRNA gene phylogeny and phenotypic traits. A second species, Holdemanella porci, was described in 2021 by Wylensek et al., after isolation from the feces of a 37-week-old pig in Bavaria, Germany.

Etymology The genus is named after Lillian Haldeman Moore (L.V. Holdeman), a pioneer in the field of anaerobic bacteriology. The species name biformis refers to its variable morphology, while porci (Latin, “of the pig”) reflects the porcine origin of the second species.

Morphology and physiology Species of Holdemanella are:

Gram-positive rods Non-spore-forming Strictly anaerobic Fermentative, primarily producing short-chain fatty acids such as butyrate

Ecology Both species of Holdemanella are members of the gut microbiota:

H. biformis has been isolated from the human colon and feces of other mammals. H. porci was recovered from the gastrointestinal tract of pigs.

Species

Holdemanella biformis The type species, H. biformis, is found in the human colon. It has been studied for its role in improving glucose metabolism and stimulating GLP-1 hormone signaling in obese mice, indicating potential metabolic benefits.

Holdemanella porci Described in 2020, H. porci was isolated from a healthy pig. Its genome and fermentation profile suggest a role in carbohydrate metabolism, but its specific effects on host physiology remain under investigation.

See also Gut microbiota Short-chain fatty acid Erysipelotrichaceae Lillian Haldeman Moore

References

External links LPSN entry for Holdemanella NCBI Taxonomy Browser: Holdemanella DSMZ entry for Holdemanella porci

Worked examples

Example 1 — a first encounter with Holdemanella

Start with the simplest possible case. Write down what Holdemanella 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 Holdemanella 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 Holdemanella 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 Holdemanella

In research: Holdemanella 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 Holdemanella 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: Holdemanella is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bacteria genera, Erysipelotrichales, Gram-positive bacteria, so understanding it makes those chapters shorter.
In everyday life: Look for Holdemanella 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 Holdemanella in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Holdemanella 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 Holdemanella out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Holdemanella in simple terms?

Why does Holdemanella 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 Holdemanella?

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 Holdemanella.