Nat Meth 2008, 5:235–237.CrossRef 27. Huse SM, Dethlefsen
L, Huber JA, Welch DM, Relman DA, Sogin ML: Exploring microbial diversity and taxonomy using SSU rRNA hypervariable tag sequencing. PLoS Genet 2008,4(11):e1000255.PubMedCrossRef Authors’ contributions JYW participated in the design of the study and performed the molecular experiments, XTJ participated in the bioinformatics analysis, SYL participated in the molecular experiments, FZ participated in the design of the study, HWZ participated in the design of the study, analyze the data and draft the manuscript. All authors read and approved the final manuscript.”
“Background Polyhydroxyalkanoates (PHA) are intracellular carbon storage polyesters that are produced by a wide variety of bacteria [1]. The most common PHA variants are so-called short chain length (scl-) PHAs Selleckchem ALK inhibitor containing monomers with 4 and/or 5 carbon-atoms [1]. Most other PHAs are referred to as medium chain length (mcl-) PHAs because the monomers generally consist of 3-hydroxyalkanoic acids with 6 or
more C-atoms [2]. These mcl-PHAs which are produced by fluorescent pseudomonads have application potential as elastomeric biodegradable plastics [3] or as sources of chiral monomers [4–6]. Pseudomonas putida accumulates mcl-PHA in discrete granules covered by a phospholipid monolayer in which various proteins are embedded [7, 8]. These granule-associated proteins include PHA polymerases (PhaC), PHA depolymerase (PhaZ) [9–11], CYC202 nmr phasins (PhaF and PhaI) [7, 12, 13] and acyl-CoA synthetase [14]. PHA polymerases (also referred to as PHA synthases), which use CoA-activated 3-hydroxy
fatty acids as substrates, are the key enzymes in mcl-PHA biosynthesis [15]. In P. putida U, two PHA polymerases encoded by phaC1 and phaC2 are known MycoClean Mycoplasma Removal Kit [16]. Disruption of phaC2 appeared to reduce the accumulation of PHA by two thirds, whereas disruption of phaC1 resulted in a complete loss of PHA accumulation [16]. Intracellular mcl-PHA degradation proceeds through the action of a PHA depolymerase encoded by phaZ. The enzyme has been suggested to act via an exo-acting hydrolytic mechanism [17]. The major amount of granule associated proteins in P. putida is accounted for by the phasins PhaI and PhaF [12, 13]. These amphiphilic proteins undoubtedly have a structural role in the granule, by which a barrier is created between the hydrophobic surface of the polymer and the surrounding hydrophilic cytoplasm [18]. In addition, PhaF may also regulate PHA metabolism at the transcriptional level [13]. Little is known of how mcl-PHA accumulation and degradation are controlled in pseudomonads. Previous studies have demonstrated that in P. putida, PHA polymerases and PHA depolymerase are concomitantly active, resulting in parallel synthesis and degradation [19].