Disease relevance of Poly-3-hydroxyoctanoate

• phaZPfi, the gene encoding the extracellular poly(3-hydroxyoctanoic acid) depolymerase of Pseudomonas fluorescens GK13, was cloned, sequenced, and characterized [1].
• Moreover, the polymer accumulated in the recombinant E. coli consisted mainly of 3-hydroxyoctanoate monomers [2].
• Twenty-five gram-negative bacteria and one gram-positive bacterium capable of growing on poly(3-hydroxyoctanoic acid) [P(3HO)] as the sole source of carbon and energy were isolated from various soils, lake water, and activated sludge [3].
• This result also provided evidence for the presumption that the Burkholderia strain possesses not only polyhydroxybutyrate synthase genes, but also synthase for medium-chain-length polyhydroxyalkanoates consisting of 3HHx, 3HO and 3HD [4].
• The kinetic DSC study of PHA granules, which contained mostly 3-hydroxyoctanoate units (PHO), in Pseudomonas putida BM01 cells showed that the polymer within the granules existed in an amorphous state, but it crystallized after dehydration of the cells under freeze-drying condition (below -50 degrees C) followed by annealing at ambient temperature [5].

High impact information on Poly-3-hydroxyoctanoate

• The dimeric ester of 3-hydroxyoctanoic acid was identified as the main product of enzymatic hydrolysis of P(3HO).(ABSTRACT TRUNCATED AT 250 WORDS)[3]
• At initial pH 11, PHA containing 3-hydroxyoctanoic acid and 3-hydroxyhexanoic acid was degraded with an efficiency of over 90% (w/w) in 9 h, and the yield of the corresponding monomers was also over 90% [6].
• When one of these 3-ketoacyl-acyl carrier protein reductase genes was co-expressed with the Pseudomonas sp. 61-3 PHA synthase gene (phaC2(Ps)) in E. coli W3110, MCL-PHA composed mainly of 3-hydroxyoctanoate and 3-hydroxydecanoate was synthesized from sodium decanoate [7].
• Over 1% PHA consisting of 3-hydroxyhexanoate (3HHx), 3-hydroxyoctanoate (3HO) and 3-hydroxydecanoate (3HD) was detected from cells of recombinant E. coli KM32B (pHXM11) harboring phaC1(Bc), grown on octanoate [4].
• Substrate specificities of poly(hydroxyalkanoate)-degrading bacteria and active site studies on the extracellular poly(3-hydroxyoctanoic acid) depolymerase of Pseudomonas fluorescens GK13 [8].

Associations of Poly-3-hydroxyoctanoate with other chemical compounds

• Gas chromatography/mass spectrometry of the trimethylsilyl derivative of one of the unknown compounds suggested the structure of 3-hydroxyoctanoic acid, which was confirmed by similar analysis of the authentic compound [9].

Gene context of Poly-3-hydroxyoctanoate

• These included 24% poly-3-hydroxybutyrate (PHB), 41% poly-3-hydroxyvalerate (PHV), 18% poly-3-hydroxyhexanoate (PHH), 10% poly-3-hydroxyoctanoate (PHO), 5% poly-3-hydroxydecanoate (PHD). and 2% poly-3-hydroxydodecanoate (PHDD), indicating that microorganisms could store various PHAs through the different metabolic pathways [10].

Analytical, diagnostic and therapeutic context of Poly-3-hydroxyoctanoate

• Chiral gas chromatography analysis confirmed that both 3-hydroxyoctanoic acid and 3-hydroxyoctanoic acid methylester are present in the R-form at a very high enantiomeric excess (>99.9%) [11].
• The monomers (e.g., 3-hydroxyoctanoic acid) were further isolated using solid phase extraction and purified on reversed phase semipreparative liquid chromatography [6].

References