science

Pseudideonella sakaiensis

Pseudideonella sakaiensis 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 Pseudideonella sakaiensis rather than just read about it. In short: Pseudideonella sakaiensis is an aerobic, Gram-negative bacterium in the family Sphaerotilaceae. Formerly known as Ideonella sakaiensis, it is notable for its ability to degrade and assimilate low-crystallinity polyethylene terephthalate (PET), using PET-derived compounds as carbon and energy sources.

Key takeaways

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

Reference excerpt

Pseudideonella sakaiensis is an aerobic, Gram-negative bacterium in the family Sphaerotilaceae. Formerly known as Ideonella sakaiensis, it is notable for its ability to degrade and assimilate low-crystallinity polyethylene terephthalate (PET), using PET-derived compounds as carbon and energy sources. The type strain, 201-F6, was isolated from a microbial consortium collected at a PET-bottle recycling site in Sakai, Japan.

Taxonomy The species was originally classified as Ideonella sakaiensis on the basis of its phenotypic characteristics, 16S rRNA gene sequence, and DNA–DNA relatedness to other members of Ideonella. A genome-based taxonomic revision subsequently transferred it to Piscinibacter as Piscinibacter sakaiensis. Further 16S rRNA and phylogenomic analyses showed that the species occupied a distinct position from both Ideonella and Piscinibacter. It was consequently transferred to the monotypic genus Pseudideonella as Pseudideonella sakaiensis.

Characteristics Cells of P. sakaiensis are aerobic, non-spore-forming rods measuring approximately 0.6–0.8 μm in width and 1.2–1.5 μm in length. They are motile by means of a polar flagellum. The organism is catalase-positive and oxidase-positive. The type strain grows at temperatures between 15 and 42 °C, with optimum growth at 30–37 °C. Growth occurs between pH 5.5 and 9.0, with an optimum between pH 7.0 and 7.5.

PET degradation and assimilation P. sakaiensis produces two enzymes that act sequentially during PET degradation. A secreted PET hydrolase, commonly called PETase, hydrolyzes ester bonds in PET and produces soluble compounds, principally mono(2-hydroxyethyl) terephthalate (MHET), together with smaller amounts of bis(2-hydroxyethyl) terephthalate (BHET) and terephthalic acid (TPA). A second enzyme, MHET hydrolase or MHETase, hydrolyzes MHET into TPA and ethylene glycol. The resulting monomers can be transported into the cell and metabolized.

Under laboratory conditions, the wild-type bacterium degraded a thin film of low-crystallinity PET over approximately six weeks at 30 °C. Its activity is strongly affected by the physical properties of the polymer. Amorphous PET films and amorphous portions of consumer containers can support bacterial growth, whereas highly crystalline PET from the main body of plastic water bottles does not support comparable growth or degradation.

Enzyme engineering PETase and MHETase have been investigated as components of enzymatic PET-recycling systems. Combining the two enzymes increased PET depolymerization by preventing the accumulation of MHET. Engineered fusion proteins containing PETase and MHETase also displayed greater activity than the separate wild-type enzymes under experimental conditions. An engineered variant derived from the PETase of P. sakaiensis, called FAST-PETase, was developed using structure-based machine learning. It showed increased activity and stability between 30 and 50 °C and depolymerized a range of post-consumer, predominantly amorphous PET products under laboratory conditions. Thermal pretreatment was still required for complete degradation of an entire PET water bottle.

See also Biodegradation of plastic PET bottle recycling Plastivore

References

External links Type strain of Pseudideonella sakaiensis at BacDive

Worked examples

Example 1 — a first encounter with Pseudideonella sakaiensis

Start with the simplest possible case. Write down what Pseudideonella sakaiensis 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 Pseudideonella sakaiensis 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 Pseudideonella sakaiensis 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 Pseudideonella sakaiensis

In research: Pseudideonella sakaiensis 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 Pseudideonella sakaiensis 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: Pseudideonella sakaiensis is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bacteria described in 2016, Burkholderiales, Plastivores, so understanding it makes those chapters shorter.
In everyday life: Look for Pseudideonella sakaiensis 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 Pseudideonella sakaiensis in 20 minutes

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

Frequently asked questions

What is Pseudideonella sakaiensis in simple terms?

Why does Pseudideonella sakaiensis 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 Pseudideonella sakaiensis?

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 Pseudideonella sakaiensis.