science

Gracilibacteria

Gracilibacteria is a science 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 Gracilibacteria rather than just read about it. In short: Gracilibacteria is a bacterial candidate phylum formerly known as GN02, BD1-5, or SN-2. It is part of the Candidate Phyla Radiation and the Patescibacteria group.

Key takeaways

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

Reference excerpt

Gracilibacteria is a bacterial candidate phylum formerly known as GN02, BD1-5, or SN-2. It is part of the Candidate Phyla Radiation and the Patescibacteria group. The first representative of the Gracilibacteria phylum was reported in 1999 after being recovered from a deep-sea sediment sample. The representative 16S rRNA sequence was referred to as "BD1-5" (sample BD1, sequence 5) and while it was noted that it displayed low sequence identity to any known 16S rRNA gene, it was not proposed as a new phylum at this time. In 2006, representatives of Gracilibacteria were recovered from a hypersaline microbial mat from Guerrero Negro, Baja California Sur, Mexico and proposed as a new phylum "GN02". The name "Gracilibacteria" was proposed for the BD1-5/GN02 lineage in 2013, based on a substantial expansion of the genomic representation of this phylum. The first Gracilibacteria genome was recovered from an acetate-amended aquifer (Rifle, CO, USA) using culture-independent, genome-resolved metagenomic techniques in 2012. Genomic analyses suggest that members of the Gracilibacteria phylum have limited metabolisms and are likely symbionts or endosymbionts. Members of Gracilibacteria use an alternative genetic code in which UGA encodes the glycine amino acid instead of a stop codon

Phylogeny

Taxonomy The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI). Clade "Gracilibacteria" cluster

Class "Vampirococcia" Pallen, Rodriguez-R & Alikhan 2022 (SR1; JAEDAM01) Order "Absconditibacterales" Yakimov et al. 2022 corrig. Kostovski, Oren & Göker 2025 Family "Absconditicoccaceae" Yakimov et al. 2022 ?Genus "Candidatus Strigamonas" Bouderka et al. 2024 Species "Ca. S. methylophilicida" Bouderka et al. 2024 Genus "Candidatus Absconditicoccus" Yakimov et al. 2022 Species "Ca. A. praedator" Yakimov et al. 2022 Genus "Candidatus Vampirococcus" Guerrero et al. 1986 non Kizina 2017 Species "Ca. V. lugosii" Moreira et al. 2021 Order BD1-5 Family UBA6164 Genus "Candidatus' Altimarinus" Rinke et al. 2013 Species "Ca.' A. pacificus" Rinke et al. 2013 Class "Gracilibacteriia" Yakimov et al. 2022 Order "Peribacterales" Anantharaman et al. 2016 Family "Peribacteraceae" Anantharaman et al. 2016 Genus "Candidatus Peribacter" Anantharaman et al. 2016 Species "Ca. P. riflensis" Anantharaman et al. 2016

References

Worked examples

Example 1 — a first encounter with Gracilibacteria

Start with the simplest possible case. Write down what Gracilibacteria claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 Gracilibacteria 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 Gracilibacteria 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 Gracilibacteria

In research: Gracilibacteria appears in science 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 Gracilibacteria 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: Gracilibacteria is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bacteria phyla, Candidatus taxa, so understanding it makes those chapters shorter.
In everyday life: Look for Gracilibacteria 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 Gracilibacteria in 20 minutes

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

Frequently asked questions

What is Gracilibacteria in simple terms?

Gracilibacteria is a bacterial candidate phylum formerly known as GN02, BD1-5, or SN-2. It is part of the Candidate Phyla Radiation and the Patescibacteria group.

Why does Gracilibacteria matter?

Because it connects several science 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 Gracilibacteria?

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 Gracilibacteria.