Polyhydroxyalkanoates

López, Nancy I.; Pettinari, M. Julia; Nikel, Pablo I.; Méndez, Beatriz S.

doi:10.1016/bs.aambs.2015.06.001

Cited by 63 publications

(27 citation statements)

References 134 publications

(130 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…P. putida KT2440 has been used many times for mcl-PHAs production using different carbon sources. In addition, the molecular background of mcl-PHAs synthesis has been investigated in many studies so far, providing valuable information about the metabolic pathways leading to mcl-PHAs synthesis, the genes coding for the enzymes that are the engines of these conversion pathways (reviewed in [40]), and the molecular regulation of these transformations (reviewed in [28]). However, the overall picture of the molecular mechanisms related to mcl-PHAs synthesis is not clear.…”

Section: Introductionmentioning

confidence: 99%

Transcriptome remodeling of Pseudomonas putida KT2440 during mcl-PHAs synthesis: effect of different carbon sources and response to nitrogen stress

Możejko-Ciesielska

Pokój

Ciesielski

2018

Journal of Industrial Microbiology and Biotechnology

View full text Add to dashboard Cite

Bacterial response to environmental stimuli is essential for survival. In response to fluctuating environmental conditions, the physiological status of bacteria can change due to the actions of transcriptional regulatory machinery. The synthesis and accumulation of polyhydroxyalkanoates (PHAs) are one of the survival strategies in harsh environments. In this study, we used transcriptome analysis of Pseudomonas putida KT2440 to gain a genome-wide view of the mechanisms of environmental-friendly biopolymers accumulation under nitrogen-limiting conditions during conversion of metabolically different carbon sources (sodium gluconate and oleic acid). Transcriptomic data revealed that phaG expression is associated with medium-chain-length-PHAs’ synthesis not only on sodium gluconate but also on oleic acid, suggesting that PhaG may play a role in this process, as well. Moreover, genes involved in the β-oxidation pathway were induced in the PHAs production phase when sodium gluconate was supplied as the only carbon and energy source. The transition from exponential growth to stationary phase caused a significant expression of genes involved in nitrogen metabolism, energy supply, and transport system. In this study, several molecular mechanisms, which drive mcl-PHAs synthesis, have been investigated. The identified genes may provide valuable information to improve the efficiency of this bioprocess and make it more economically feasible.Electronic supplementary materialThe online version of this article (10.1007/s10295-018-2042-4) contains supplementary material, which is available to authorized users.

show abstract

Section: Introductionmentioning

confidence: 99%

Transcriptome remodeling of Pseudomonas putida KT2440 during mcl-PHAs synthesis: effect of different carbon sources and response to nitrogen stress

Możejko-Ciesielska

Pokój

Ciesielski

2018

Journal of Industrial Microbiology and Biotechnology

View full text Add to dashboard Cite

show abstract

“…It has been suggested that PhaG encodes transacylase, being not co-localized with the pha gene cluster, is also involved in mcl-PHAs synthesis from non-related carbon sources (Hoffmann and Rehm 2004). It is known that PHAs are accumulated by pseudomonads mainly in response to unbalanced growth conditions such as a lack of nitrogen, which links PHAs accumulation to the stringent response (López et al 2015). …”

Section: Introductionmentioning

confidence: 99%

Medium-chain-length polyhydroxyalkanoates synthesis by Pseudomonas putida KT2440 relA/spoT mutant: bioprocess characterization and transcriptome analysis

et al. 2017

View full text Add to dashboard Cite

Pseudomonas putida KT2440 is a model bacteria used commonly for medium-chain-length polyhydroxyalkanoates (mcl-PHAs) production using various substrates. However, despite many studies conducted on P. putida KT2440 strain, the molecular mechanisms of leading to mcl-PHAs synthesis in reaction to environmental stimuli are still not clear. The rearrangement of the metabolism in response to environmental stress could be controlled by stringent response that modulates the transcription of many genes in order to promote survival under nutritional deprivation conditions. Therefore, in this work we investigated the relation between mcl-PHAs synthesis and stringent response. For this study, a relA/spoT mutant of P. putida KT2440, unable to induce the stringent response, was used. Additionally, the transcriptome of this mutant was analyzed using RNA-seq in order to examine rearrangements of the metabolism during cultivation. The results show that the relA/spoT mutant of P. putida KT2440 is able to accumulate mcl-PHAs in both optimal and nitrogen limiting conditions. Nitrogen starvation did not change the efficiency of mcl-PHAs synthesis in this mutant. The transition from exponential growth to stationary phase caused significant upregulation of genes involved in transport system and nitrogen metabolism. Transcriptional regulators, including rpoS, rpoN and rpoD, did not show changes in transcript abundance when entering the stationary phase, suggesting their limited role in mcl-PHAs accumulation during stationary phase.Electronic supplementary materialThe online version of this article (doi:10.1186/s13568-017-0396-z) contains supplementary material, which is available to authorized users.

show abstract

“…Among the different regulatory systems of E. coli, ArcAB has attracted significant attention in the last few years, as manipulations in this sensor/regulator pair offer the possibility of directing carbon flow toward the synthesis of reduced bioproducts under low-aeration conditions (15)(16)(17). In our laboratory, we analyzed the effects of arcA mutants on the central carbon catabolism of E. coli using glucose and glycerol in microaerobiosis and anaerobiosis and observed that mutations in arcA resulted in significant increases in the synthesis of polyhydroxyalkanoates (18)(19)(20)(21) and ethanol (22,23). In these studies, the constitutive allele creC510 was observed to affect the intracellular redox state, enhancing carbon catabolism in an arcA genetic background so that part of the excess reducing power generated by the arcA mutants was consumed by the augmented amount of carbon intermediates due to creC510, further increasing the synthesis of reduced products (18).…”

mentioning

confidence: 99%

The CreC Regulator of Escherichia coli, a New Target for Metabolic Manipulations

Godoy

Nikel

Gomez

et al. 2016

Appl Environ Microbiol

Self Cite

View full text Add to dashboard Cite

The CreBC (carbon source-responsive) two-component regulation system of Escherichia coli affects a number of functions, including intermediary carbon catabolism. The impacts of different creC mutations (a ⌬creC mutant and a mutant carrying the constitutive creC510 allele) on bacterial physiology were analyzed in glucose cultures under three oxygen availability conditions. Differences in the amounts of extracellular metabolites produced were observed in the null mutant compared to the wild-type strain and the mutant carrying creC510 and shown to be affected by oxygen availability. The ⌬creC strain secreted more formate, succinate, and acetate but less lactate under low aeration. These metabolic changes were associated with differences in AckA and LdhA activities, both of which were affected by CreC. Measurement of the NAD(P)H/NAD(P) ؉ ratios showed that the creC510 strain had a more reduced intracellular redox state, while the opposite was observed for the ⌬creC mutant, particularly under intermediate oxygen availability conditions, indicating that CreC affects redox balance. The null mutant formed more succinate than the wild-type strain under both low aeration and no aeration. Overexpression of the genes encoding phosphoenolpyruvate carboxylase from E. coli and a NADH-forming formate dehydrogenase from Candida boidinii in the ⌬creC mutant further increased the yield of succinate on glucose. Interestingly, the elimination of ackA and adhE did not significantly improve the production of succinate. The diverse metabolic effects of this regulator on the central biochemical network of E. coli make it a good candidate for metabolic-engineering manipulations to enhance the formation of bioproducts, such as succinate.T he survival of an organism depends, at least in part, on its ability to sense and respond to changes in the environment. In bacteria, global regulators control the transcription of genes in response to specific external stimuli and metabolic signals, finely tuning different aspects of their physiology to overcome environmental challenges. In Escherichia coli, seven global regulators (ArcA, Crp, Fis, Fnr, Ihf, Lrp, and NarL) directly modulate the expression of about one-half of all genes (1). This facultative aerobe is able to adapt its metabolism to different oxygen availability conditions through the concerted actions of a network of regulators, including the global regulators ArcAB and Fnr (2-4). These regulators affect many metabolic pathways, allowing the cells to reach an adequate redox balance under any given conditions. There is a very close association between carbon and electron flows, and even small differences in oxygen availability have been observed to elicit profound effects on the distribution of carbon fluxes (5).CreBC (for carbon source responsive) is a global sensing and regulation system affecting genes involved in a variety of functions, including enzymes of intermediary catabolism (6). Previous studies have shown that the creABCD operon is activated (i) during growth in minimal mediu...

show abstract

Polyhydroxyalkanoates

Cited by 63 publications

References 134 publications

Transcriptome remodeling of Pseudomonas putida KT2440 during mcl-PHAs synthesis: effect of different carbon sources and response to nitrogen stress

Transcriptome remodeling of Pseudomonas putida KT2440 during mcl-PHAs synthesis: effect of different carbon sources and response to nitrogen stress

Medium-chain-length polyhydroxyalkanoates synthesis by Pseudomonas putida KT2440 relA/spoT mutant: bioprocess characterization and transcriptome analysis

The CreC Regulator of Escherichia coli, a New Target for Metabolic Manipulations

Contact Info

Product

Resources

About