Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (737 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
Biodegradable microbial polyesters which contain hydroxyacyl monomers. Polyhydroxyalkanoates are carbon and energy reserve materials produced and sequestered in cytoplasmic granules called polyhydroxyalkanoate or PHA granules by various archaea and bacteria and may additionally provide protective mechanism to the microbes. They are biosynthesized by microbial polyhydroxyalkanoate synthase enzymes using fatty acids or citramalate synthase enzymes using glucose.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Polyhydroxyalkanoate; Poly(hydroxyalkanoates); Poly(hydroxyalkanoate).
Where it fits in the MeSH classification
- Broader topics
- Biopolymers; Polyesters; Lipids
- Narrower topics
- Polyhydroxybutyrates
Research landscape
PubMed indexes 4,885 records tagged with the MeSH heading “Polyhydroxyalkanoates” (counts retrieved 2026-10-31). 1,729 of them (35.4%) were published from 2020 onward, and the busiest period so far is 2010-2019 with 2,030 records.
Reviews account for 432 records (8.8%) and meta-analyses for 1. Randomized controlled trials number 2 (0.0%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 213 |
| 2000-2009 | 913 |
| 2010-2019 | 2,030 |
| 2020 onward | 1,729 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 432 | 8.8% |
| Meta-analyses | 1 | 0.0% |
| Randomized controlled trials | 2 | 0.0% |
Method: PubMed query "Polyhydroxyalkanoates"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-31.
Reading the evidence in drugs and chemicals
Studies of a chemical or drug can answer very different questions: what it is and how it behaves in cells and animals, how the body handles it, and whether it changes outcomes in people. Laboratory and animal findings often do not carry over to patients, and observational studies of exposures are confounded by who uses a substance and why. Nothing on this page is a recommendation to use, avoid, start or stop any substance or medicine; talk to a qualified clinician or pharmacist about your own situation. Check the dose, the species, the comparison group and whether a patient-relevant outcome was measured.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Synthesis, production, and biotechnological applications of exopolysaccharides and polyhydroxyalkanoates by archaea | 2011 | Review article Design not recorded in structured metadata | 134 | cc by PMID 22007151 · DOI · PMC3191746 |
| Current developments on polyhydroxyalkanoates synthesis by using halophiles as a promising cell factory | 2020 | Review article Design not recorded in structured metadata | 128 | cc by PMID 32264891 · DOI · PMC7137286 |
| Carbon Sources for Polyhydroxyalkanoates and an Integrated Biorefinery | 2016 | Review article Design not recorded in structured metadata | 97 | cc by PMID 27447619 · DOI · PMC4964529 |
| Production, isolation, optimization, and characterization of microbial PHA from Bacillus australimaris | 2025 | Research article Design not recorded in structured metadata | 5 | cc by PMID 40069246 · DOI · PMC11897369 |
Synthesis, production, and biotechnological applications of exopolysaccharides and polyhydroxyalkanoates by archaea [1]
Abstract reading summary — source excerpts
- Opening excerpt
- Extreme environments, generally characterized by atypical temperatures, pH, pressure, salinity, toxicity, and radiation levels, are inhabited by various microorganisms specifically adapted to these particular conditions, called extremophiles.
- Closing excerpt
- Here, we report the composition, biosynthesis, and production of EPSs and PHAs by different archaeal species.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (115 words)
Extreme environments, generally characterized by atypical temperatures, pH, pressure, salinity, toxicity, and radiation levels, are inhabited by various microorganisms specifically adapted to these particular conditions, called extremophiles. Among these, the microorganisms belonging to the Archaea domain are of significant biotechnological importance as their biopolymers possess unique properties that offer insights into their biology and evolution. Particular attention has been devoted to two main types of biopolymers produced by such peculiar microorganisms, that is, the extracellular polysaccharides (EPSs), considered as a protection against desiccation and predation, and the endocellular polyhydroxyalkanoates (PHAs) that provide an internal reserve of carbon and energy. Here, we report the composition, biosynthesis, and production of EPSs and PHAs by different archaeal species.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 22007151 · DOI · PMC3191746
Current developments on polyhydroxyalkanoates synthesis by using halophiles as a promising cell factory [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Plastic pollution is a severe threat to our environment which necessitates implementation of bioplastics to realize sustainable development for a green world.
- Closing excerpt
- This review is an endeavour to summarize the various research achievements in these areas which will help the readers to understand the current developments as well as the future efforts in PHA research.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (197 words)
Plastic pollution is a severe threat to our environment which necessitates implementation of bioplastics to realize sustainable development for a green world. Polyhydroxyalkanoates (PHA) represent one of the potential candidates for these bioplastics. However, a major challenge faced by PHA is the high production cost which limits its commercial application. Halophiles are considered to be a promising cell factory for PHA synthesis due to its several unique characteristics including high salinity requirement preventing microbial contamination, high intracellular osmotic pressure allowing easy cell lysis for PHA recovery, and capability to utilize wide spectrum of low-cost substrates. Optimization of fermentation parameters has made it plausible to achieve large-scale production at low cost by using halophiles. Further deeper insights into halophiles have revealed the existence of diversified and even novel PHA synthetic pathways within different halophilic species that greatly affects PHA type. Thus, precise metabolic engineering of halophiles with the help of advanced tools and strategies have led to more efficient microbial cell factory for PHA production. This review is an endeavour to summarize the various research achievements in these areas which will help the readers to understand the current developments as well as the future efforts in PHA research.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 32264891 · DOI · PMC7137286
Carbon Sources for Polyhydroxyalkanoates and an Integrated Biorefinery [3]
Abstract reading summary — source excerpts
- Opening excerpt
- Polyhydroxyalkanoates (PHAs) are a group of bioplastics that have a wide range of applications.
- Closing excerpt
- This will create the potential to offset the production cost of biofuels and reduce the overall production cost of PHAs.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (185 words)
Polyhydroxyalkanoates (PHAs) are a group of bioplastics that have a wide range of applications. Extensive progress has been made in our understanding of PHAs' biosynthesis, and currently, it is possible to engineer bacterial strains to produce PHAs with desired properties. The substrates for the fermentative production of PHAs are primarily derived from food-based carbon sources, raising concerns over the sustainability of their production in terms of their impact on food prices. This paper gives an overview of the current carbon sources used for PHA production and the methods used to transform these sources into fermentable forms. This allows us to identify the opportunities and restraints linked to future sustainable PHA production. Hemicellulose hydrolysates and crude glycerol are identified as two promising carbon sources for a sustainable production of PHAs. Hemicellulose hydrolysates and crude glycerol can be produced on a large scale during various second generation biofuels' production. An integration of PHA production within a modern biorefinery is therefore proposed to produce biofuels and bioplastics simultaneously. This will create the potential to offset the production cost of biofuels and reduce the overall production cost of PHAs.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 27447619 · DOI · PMC4964529
Production, isolation, optimization, and characterization of microbial PHA from Bacillus australimaris [4]
Abstract reading summary — source excerpts
- Opening excerpt
- Population explosion in recent years has driven the environment to overuse nondegradable substances.
- Closing excerpt
- The media optimization was performed via Minitab software, with statistical analyses employed to interpret the resulting data comprehensively.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (240 words)
Population explosion in recent years has driven the environment to overuse nondegradable substances. Microbial polyesters known as polyhydroxyalkanoates (PHAs) are generated and retained as cytoplasmic granules in microorganisms with restricted nutritional availability and can be used to manufacture bioplastics. The current study attempts to screen soil isolates for PHA production and optimize their media parameters. Among all the isolates, 17 were identified and confirmed by Sudan black staining, as they are screening for PHA production and are identified by their colony characteristics. The isolation of the most promising strain, GS-14, was achieved through the sodium hypochlorite method, and subsequent quantification involved establishing a standard curve of crotonic acid. Notably, isolate GS-14 presented the highest yield, which was determined by extrapolating its data onto the standard curve. Characterization of the PHA polymer was subsequently performed, and the results were used to discern its properties. FTIR confirmed characteristic PHA absorption bands, with a prominent C = O stretching peak at 1732 cm⁻¹. LC-MS detected a molecular mass of 641.6 g/mol, indicative of an oligomeric species, while the actual polymer molecular weight is estimated between 5,000 and 20,000 Da. DSC revealed an exothermic peak at 174 °C, allowing the calculation of crystallinity, a key determinant of mechanical properties. Furthermore, the PHA-producing organism was identified as Bacillus australimaris through the sequencing of 16 S ribosomal RNA. The media optimization was performed via Minitab software, with statistical analyses employed to interpret the resulting data comprehensively.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 40069246 · DOI · PMC11897369
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Microbial production of polyhydroxyalkanoates (PHAs) and its copolymers: A review of recent advancements [5]
- Research article Producing microbial polyhydroxyalkanoate (PHA) biopolyesters in a sustainable manner [6]
- Research article Bacterial polyhydroxyalkanoates: Still fabulous? [7]
- Research article Halophiles, coming stars for industrial biotechnology [8]
- Research article New insights in the formation of polyhydroxyalkanoate granules (carbonosomes) and novel functions of poly(3-hydroxybutyrate) [9]
- Research article A holistic view of polyhydroxyalkanoate metabolism in Pseudomonas putida [10]
References
- Poli A, Di Donato P, Abbamondi GR, Nicolaus B. Synthesis, production, and biotechnological applications of exopolysaccharides and polyhydroxyalkanoates by archaea. . 2011. PMID 22007151 · DOI · PMC3191746
- Mitra R, Xu T, Xiang H, Han J. Current developments on polyhydroxyalkanoates synthesis by using halophiles as a promising cell factory. . 2020. PMID 32264891 · DOI · PMC7137286
- Jiang G, Hill DJ, Kowalczuk M, Johnston B, Adamus G, Irorere V, et al.. Carbon Sources for Polyhydroxyalkanoates and an Integrated Biorefinery. . 2016. PMID 27447619 · DOI · PMC4964529
- Ibrahim R, Aranjani JM, Prasanna N, Biswas A, Gayam PKR. Production, isolation, optimization, and characterization of microbial PHA from Bacillus australimaris. . 2025. PMID 40069246 · DOI · PMC11897369
- Anjum A, Zuber M, Zia KM, Noreen A, Anjum MN, Tabasum S. Microbial production of polyhydroxyalkanoates (PHAs) and its copolymers: A review of recent advancements. Int J Biol Macromol. 2016. PMID 27126172 · DOI
- Koller M, Maršálek L, de Sousa Dias MM, Braunegg G. Producing microbial polyhydroxyalkanoate (PHA) biopolyesters in a sustainable manner. N Biotechnol. 2017. PMID 27184617 · DOI
- Możejko-Ciesielska J, Kiewisz R. Bacterial polyhydroxyalkanoates: Still fabulous?. Microbiol Res. 2016. PMID 27664746 · DOI
- Yin J, Chen JC, Wu Q, Chen GQ. Halophiles, coming stars for industrial biotechnology. Biotechnol Adv. 2015. PMID 25447783 · DOI
- Jendrossek D, Pfeiffer D. New insights in the formation of polyhydroxyalkanoate granules (carbonosomes) and novel functions of poly(3-hydroxybutyrate). Environ Microbiol. 2014. PMID 24329995 · DOI
- Prieto A, Escapa IF, Martínez V, Martínez V, Dinjaski N, Herencias C, et al.. A holistic view of polyhydroxyalkanoate metabolism in Pseudomonas putida. Environ Microbiol. 2016. PMID 25556983 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-31.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.