scholarly journals Identification and characterization of an acyl-CoA dehydrogenase from Pseudomonas putida KT2440 that shows preference towards medium to long chain length fatty acids

Microbiology ◽  
2014 ◽  
Vol 160 (8) ◽  
pp. 1760-1771 ◽  
Author(s):  
Maciej W. Guzik ◽  
Tanja Narancic ◽  
Tatjana Ilic-Tomic ◽  
Sandra Vojnovic ◽  
Shane T. Kenny ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Pseudomonas Putida ◽  
Chain Length ◽  
Recombinant Expression ◽  
Nutrient Utilization ◽  
Ecological Niches ◽  
Fatty Acid Degradation ◽  
Acid Degradation

Diverse and elaborate pathways for nutrient utilization, as well as mechanisms to combat unfavourable nutrient conditions make Pseudomonas putida KT2440 a versatile micro-organism able to occupy a range of ecological niches. The fatty acid degradation pathway of P. putida is complex and correlated with biopolymer medium chain length polyhydroxyalkanoate (mcl-PHA) biosynthesis. Little is known about the second step of fatty acid degradation (β-oxidation) in this strain. In silico analysis of its genome sequence revealed 21 putative acyl-CoA dehydrogenases (ACADs), four of which were functionally characterized through mutagenesis studies. Four mutants with insertionally inactivated ACADs (PP_1893, PP_2039, PP_2048 and PP_2437) grew and accumulated mcl-PHA on a range of fatty acids as the sole source of carbon and energy. Their ability to grow and accumulate biopolymer was differentially negatively affected on various fatty acids, in comparison to the wild-type strain. Inactive PP_2437 exhibited a pattern of reduced growth and PHA accumulation when fatty acids with lengths of 10 to 14 carbon chains were used as substrates. Recombinant expression and biochemical characterization of the purified protein allowed functional annotation in P. putida KT2440 as an ACAD showing clear preference for dodecanoyl-CoA ester as a substrate and optimum activity at 30 °C and pH 6.5–7.

scholarly journals Engineering the Monomer Composition of Polyhydroxyalkanoates Synthesized in Saccharomyces cerevisiae

2006 ◽  
Vol 72 (1) ◽  
pp. 536-543 ◽  
Author(s):  
Bo Zhang ◽  
Ross Carlson ◽  
Friedrich Srienc
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acid ◽  
Chain Length ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Pha Synthase ◽  
Fatty Acid Degradation ◽  
Medium Chain ◽  
Acid Degradation ◽  
Wide Range

ABSTRACT Polyhydroxyalkanoates (PHAs) have received considerable interest as renewable-resource-based, biodegradable, and biocompatible plastics with a wide range of potential applications. We have engineered the synthesis of PHA polymers composed of monomers ranging from 4 to 14 carbon atoms in either the cytosol or the peroxisome of Saccharomyces cerevisiae by harnessing intermediates of fatty acid metabolism. Cytosolic PHA production was supported by establishing in the cytosol critical β-oxidation chemistries which are found natively in peroxisomes. This platform was utilized to supply medium-chain (C6 to C14) PHA precursors from both fatty acid degradation and synthesis to a cytosolically expressed medium-chain-length (mcl) polymerase from Pseudomonas oleovorans. Synthesis of short-chain-length PHAs (scl-PHAs) was established in the peroxisome of a wild-type yeast strain by targeting the Ralstonia eutropha scl polymerase to the peroxisome. This strain, harboring a peroxisomally targeted scl-PHA synthase, accumulated PHA up to approximately 7% of its cell dry weight. These results indicate (i) that S. cerevisiae expressing a cytosolic mcl-PHA polymerase or a peroxisomal scl-PHA synthase can use the 3-hydroxyacyl coenzyme A intermediates from fatty acid metabolism to synthesize PHAs and (ii) that fatty acid degradation is also possible in the cytosol as β-oxidation might not be confined only to the peroxisomes. Polymers of even-numbered, odd-numbered, or a combination of even- and odd-numbered monomers can be controlled by feeding the appropriate substrates. This ability should permit the rational design and synthesis of polymers with desired material properties.

TetR-family transcriptional repressor Thermus thermophilus FadR controls fatty acid degradation

Microbiology ◽  
2011 ◽  
Vol 157 (6) ◽  
pp. 1589-1601 ◽  
Author(s):  
Yoshihiro Agari ◽  
Kazuko Agari ◽  
Keiko Sakamoto ◽  
Seiki Kuramitsu ◽  
Akeo Shinkai
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Target Genes ◽  
Thermus Thermophilus ◽  
Acyl Chain ◽  
Metabolic Energy ◽  
Straight Chain ◽  
Fatty Acid Degradation ◽  
Acid Degradation

In the extremely thermophilic bacterium Thermus thermophilus HB8, one of the four TetR-family transcriptional regulators, which we named T. thermophilus FadR, negatively regulated the expression of several genes, including those involved in fatty acid degradation, both in vivo and in vitro. T. thermophilus FadR repressed the expression of the target genes by binding pseudopalindromic sequences covering the predicted −10 hexamers of their promoters, and medium-to-long straight-chain (C10–18) fatty acyl-CoA molecules were effective for transcriptional derepression. An X-ray crystal structure analysis revealed that T. thermophilus FadR bound one lauroyl (C12)-CoA molecule per FadR monomer, with its acyl chain moiety in the centre of the FadR molecule, enclosed within a tunnel-like substrate-binding pocket surrounded by hydrophobic residues, and the CoA moiety interacting with basic residues on the protein surface. The growth of T. thermophilus HB8, with palmitic acid as the sole carbon source, increased the expression of FadR-regulated genes. These results indicate that in T. thermophilus HB8, medium-to-long straight-chain fatty acids can be used for metabolic energy under the control of FadR, although the major fatty acids found in this strain are iso- and anteiso-branched-chain (C15 and 17) fatty acids.

Structural characterization of a ligand-bound form ofBacillus subtilisFadR involved in the regulation of fatty acid degradation

2014 ◽  
Vol 82 (7) ◽  
pp. 1301-1310 ◽  
Author(s):  
Masahiro Fujihashi ◽  
Taiga Nakatani ◽  
Kazutake Hirooka ◽  
Hiroshi Matsuoka ◽  
Yasutaro Fujita ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Structural Characterization ◽  
Fatty Acid Degradation ◽  
Acid Degradation

scholarly journals The Thermal and Mechanical Properties of Medium Chain-Length Polyhydroxyalkanoates Produced by Pseudomonas putida LS46 on Various Substrates

2021 ◽  
Vol 8 ◽  
Author(s):  
Christopher Dartiailh ◽  
Warren Blunt ◽  
Parveen K. Sharma ◽  
Song Liu ◽  
Nazim Cicek ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Tensile Strength ◽  
Fatty Acid ◽  
Pseudomonas Putida ◽  
Chain Length ◽  
Substrate Effect ◽  
Mechanical And Thermal Properties ◽  
Medium Chain ◽  
Molecular Weights ◽  
Medium Chain Length

Medium chain-length polyhydroxyalkanoates (mcl-PHA) were produced by Pseudomonas putida LS46 cultured with a variety of carbohydrate and fatty acid substrates. The monomer compositions and molecular weights of the polymers varied greatly and was dependent on whether the substrate was metabolized via the fatty acid degradation or the de novo fatty acid synthesis pathways. The highest molecular weights were obtained from medium chain-length fatty acids, whereas low molecular weights were obtained from longer chain-length and more unsaturated fatty acids or carbohydrates. The differences in monomer compositions and molecular weights due to the choice of substrate did not affect the polymer thermal degradation point. The glass transition temperatures varied from −39.4°C to −52.7°C. The melting points, when observed, ranged from 43.2°C to 51.2°C. However, a profound substrate effect was observed on the crystallinity of these polymers. Reduced crystallinity was observed when the monomer compositions deviated away from C8–C10 monomer lengths. The highest crystallinity was observed from medium chain-length fatty acids, which resulted in polymers with the highest tensile strength. The polymer produced from octanoic acid exhibited the highest tensile strength of 4.3 MPa with an elongation-at-break of 162%, whereas the polymers produced from unsaturated, long-chain fatty acids remained amorphous. A comparative analysis of the substrate effect on the physical-mechanical and thermal properties of mcl-PHAs better clarifies the relationship between the monomer composition and their potential applications, and also aids to direct future PHA synthesis research toward properties of interest.

β-Oxidation of fatty acids by Leptospira

1970 ◽  
Vol 16 (1) ◽  
pp. 41-45 ◽  
Author(s):  
R. C. Henneberry ◽  
C. D. Cox
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Adenosine Triphosphate ◽  
Unsaturated Fatty Acids ◽  
Catabolic Pathway ◽  
Fatty Acid Degradation ◽  
Acid Degradation ◽  
Pathogenic Leptospire

The oxidation of both saturated and unsaturated fatty acids by a water isolate and a pathogenic leptospire is reported. Evidence is presented for the existence of an adenosine triphosphate dependent fatty acid activating enzyme in the water isolate, and measurement of the reactions of β-oxidation in cell-free extracts of both strains is described. It was concluded that fatty acid degradation by β-oxidation constitutes a major catabolic pathway in Leptospira.

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