Poly(3-hydroxybutyrate) hyperproduction by a global nitrogen regulator NtrB mutant strain of Paracoccus denitrificans PD1222.

Paracoccus denitrificans PD1222 accumulates short-length polyhydroxyalkanoates, poly(3-hydroxybutyrate), under nitrogen-deficient conditions. Polyhydroxybutyrate metabolism requires the 3-ketoacyl-CoA thiolase PhaA, the acetoacetyl-CoA dehydrogenase/reductase PhaB and the synthase PhaC for polymerization. Additionally, P.

Transcriptional and translational adaptation to aerobic nitrate anabolism in the denitrifier .

Transcriptional adaptation to nitrate-dependent anabolism by PD1222 was studied. A total of 74 genes were induced in cells grown with nitrate as N-source compared with ammonium, including and genes. The and genes were cotranscribed, although was more strongly induced by nitrate than The genes constituted a transcriptional unit, which is preceded by a non-coding region containing hairpin structures involved in transcription termination.

The nit1C gene cluster of Pseudomonas pseudoalcaligenes CECT5344 involved in assimilation of nitriles is essential for growth on cyanide.

A proteomic approach was used to identify several proteins induced by cyanide in the alkaliphilic bacterium Pseudomonas pseudoalcaligenes CECT5344, two of them, NitB and NitG, encoded by genes that belong to the nit1C gene cluster. The predicted products of the nit1C gene cluster are a Fis-like σ(54) -dependent transcriptional activator (NitA), a nitrilase (NitC), an S-adenosylmethionine superfamily member (NitD), an N-acyltransferase superfamily member (NitE), a trifunctional polypeptide of the AIRS/GARS family (NitF), an NADH-dependent oxidoreductase (NitH) and two hypothetical proteins of unknown function (NitB and NitG). RT-PCR analysis suggested that nitBCDEFGH genes were co-transcribed, whereas the regulatory nitA gene was divergently transcribed.

Draft whole genome sequence of the cyanide-degrading bacterium Pseudomonas pseudoalcaligenes CECT5344.

Pseudomonas pseudoalcaligenes CECT5344 is a Gram-negative bacterium able to tolerate cyanide and to use it as the sole nitrogen source. We report here the first draft of the whole genome sequence of a P. pseudoalcaligenes strain that assimilates cyanide.

3-Hydroxyphenylpropionate and phenylpropionate are synergistic activators of the MhpR transcriptional regulator from Escherichia coli.

The degradation of the aromatic compound phenylpropionate (PP) in Escherichia coli K-12 requires the activation of two different catabolic pathways coded by the hca and the mhp gene clusters involved in the mineralization of PP and 3-hydroxyphenylpropionate (3HPP), respectively. The compound 3-(2,3-dihydroxyphenyl)propionate (DHPP) is a common intermediate of both pathways which must be cleaved by the MhpB dioxygenase before entering into the primary cell metabolism. Therefore, the degradation of PP has to be controlled by both its specific regulator (HcaR) but also by the MhpR regulator of the mhp cluster.

The role of FIS protein in the physiological control of the expression of the Escherichia coli meta-hpa operon.

Expression from the Escherichia coli W meta-hpa operon promoter (Pg) is under a strict catabolic repression control mediated by the cAMP-catabolite repression protein (CRP) complex in a glucose-containing medium. The Pg promoter is also activated by the integration host factor (IHF) and repressed by the specific transcriptional regulator HpaR when 4-hydroxyphenylacetate (4HPA) is not present in the medium. Expression from the hpa promoter is also repressed in undefined rich medium such as LB, but the molecular basis of this mechanism is not understood.

Genetic modification of the penicillin G acylase surface to improve its reversible immobilization on ionic exchangers.

A new mutant of the industrial enzyme penicillin G acylase (PGA) from Escherichia coli has been designed to improve its reversible immobilization on anionic exchangers (DEAE- or polyethyleneimine [PEI]-coated agarose) by assembling eight new glutamic residues distributed homogeneously through the enzyme surface via site-directed mutagenesis. The mutant PGA is produced and processed in vivo as is the native enzyme. Moreover, it has a similar specific activity to and shows the same pH activity profile as native PGA; however, its isoelectric point decreased from 6.

[Prevalence of chronic hidden infections in a cohort of patients in substitutive treatment with methadone].

Background: To analyse prevalence of hidden hepatitis B infection (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and tuberculosis infection in drug users (DU) in a maintenance programme with methadone (MPM).

Patients And Method: 189 DU were tested for HBV, HCV, HIV and tuberculin test. Drug addition history and route of administration were evaluated.