Cyclic di-GMP inhibits nitrate assimilation by impairing the antitermination function of NasT in Pseudomonas putida.

The ubiquitous bacterial second messenger cyclic diguanylate (c-di-GMP) coordinates diverse cellular processes through its downstream receptors. However, whether c-di-GMP participates in regulating nitrate assimilation is unclear. Here, we found that NasT, an antiterminator involved in nitrate assimilation in Pseudomonas putida, specifically bound c-di-GMP.

The phosphodiesterase DibA interacts with the c-di-GMP receptor LapD and specifically regulates biofilm in Pseudomonas putida.

The ubiquitous bacterial second messenger c-di-GMP is synthesized by diguanylate cyclase and degraded by c-di-GMP-specific phosphodiesterase. The genome of Pseudomonas putida contains dozens of genes encoding diguanylate cyclase/phosphodiesterase, but the phenotypical-genotypical correlation and functional mechanism of these genes are largely unknown. Herein, we characterize the function and mechanism of a P.

A Polysaccharide Biosynthesis Locus in Vibrio parahaemolyticus Important for Biofilm Formation Has Homologs Widely Distributed in Aquatic Bacteria Mainly from .

Vibrio parahaemolyticus is a seafood-borne pathogen that poses a great threat to public health worldwide. It is found in either a planktonic cell or a biofilm form in the natural environment. The locus has been the only extensively studied polysaccharide biosynthesis gene cluster involved in biofilm formation for this bacterium.

Wsp system oppositely modulates antibacterial activity and biofilm formation via FleQ-FleN complex in Pseudomonas putida.

Type VI secretion systems (T6SS) are specific antibacterial weapons employed by diverse bacteria to protect themselves from competitors. Pseudomonas putida KT2440 possesses a functional T6SS (K1-T6SS) and exhibits antibacterial activity towards a broad range of bacteria. Here we found that the Wsp signal transduction system regulated K1-T6SS expression via synthesizing the second messenger cyclic di-GMP (c-di-GMP), thus mediating antibacterial activity in P.

Identification of c-di-GMP/FleQ-Regulated New Target Genes, Including , Encoding Adenylate Cyclase, in Pseudomonas putida.

The bacterial second messenger cyclic diguanylate (c-di-GMP) modulates plankton-to-biofilm lifestyle transition of species through its transcriptional regulatory effector FleQ. FleQ regulates transcription of biofilm- and flagellum-related genes in response to c-di-GMP. Through transcriptomic analysis and FleQ-DNA binding assay, this study identified five new target genes of c-di-GMP/FleQ in , including , , (), (), and Except encoding an outer membrane pore protein and encoding an adenylate cyclase, the functions of the other three genes encoding hypothetical proteins remain unknown.

The two-component system TarR-TarS is regulated by c-di-GMP/FleQ and FliA and modulates antibiotic susceptibility in Pseudomonas putida.

Two-component systems (TCSs) are predominant means by which bacteria sense and respond to environment signals. Genome of Pseudomonas putida contains dozens of putative TCS-encoding genes, but phenotypical-genotypical correlation and transcriptional regulation of these genes are largely unknown. Herein, we characterized function and transcriptional regulation of a conserved P.

Phenotypic-genotypic analysis of GGDEF/EAL/HD-GYP domain-encoding genes in Pseudomonas putida.

Cyclic diguanylate (c-di-GMP) is a broadly conserved bacterial signalling molecule that modulates diverse cellular processes, such as biofilm formation, colony morphology and swimming motility. The intracellular level of c-di-GMP is controlled by diguanylate cyclases (DGCs) with GGDEF domain and phosphodiesterases (PDEs) with either EAL or HD-GYP domain. Pseudomonas putida KT2440 has a large group of genes on its genome encoding proteins with GGDEF/EAL/HD-GYP domains.

High c-di-GMP promotes expression of fpr-1 and katE involved in oxidative stress resistance in Pseudomonas putida KT2440.

Oxidative stress is an unavoidable consequence of interactions with various reactive oxygen species (ROS)-inducing agents that would damage cells or even cause cell death. Bacteria have developed defensive systems, including induction of stress-sensing proteins and detoxification enzymes, to handle oxidative stress. Cyclic diguanylate (c-di-GMP) is a ubiquitous intracellular bacterial second messenger that coordinates diverse aspects of bacterial growth and behavior.

A crosstalk between c-di-GMP and cAMP in regulating transcription of GcsA, a diguanylate cyclase involved in swimming motility in Pseudomonas putida.

The ubiquitous bacterial second messenger c-di-GMP is synthesized by diguanylate cyclase (DGC) and degraded by phosphodiesterase (PDE). Pseudomonas putida has dozens of DGC/PDE-encoding genes in its genome, but the phenotypical-genotypical correlation and transcriptional regulation of these genes are largely unknown. Herein, we characterize function and transcriptional regulation of a P.

The exopolysaccharide gene cluster pea is transcriptionally controlled by RpoS and repressed by AmrZ in Pseudomonas putida KT2440.

In Pseudomonas putida KT2440, the exopolysaccharide Pea is associated with biofilm stability and pellicle formation; however, little is known about its regulatory pathway. In this study, we identified that the gene cluster pea was transcribed from 25 bp upstream of the operon and the stationary phase alternative sigma factor RpoS regulated the transcription of pea. When RpoS was absent, another sigma factor, likely the housekeeping sigma factor RpoD, could also mediate pea transcription but at a low level.

FinR Regulates Expression of and Operons, Involved in Nicotinic Acid Degradation in Pseudomonas putida KT2440.

Many proteobacteria harbor FinR homologues in their genomes as putative LysR-type proteins; however, the function of FinR is poorly studied except in the induction of under superoxide stress conditions in and Here, by analyzing the influence of deletion on the transcriptomic profile of KT2440 through RNA sequencing and real-time quantitative PCR (RT-qPCR), we found 11 operons that are potentially regulated by FinR. Among them, the expression of and operons, which were reported to be responsible for the aerobic degradation of nicotinic acid (NA), was significantly decreased in the mutant, and complementation with intact restored the expression of the two operons. The results of bacterial NA utilization demonstrated that the deletion of impaired bacterial growth in minimal medium supplemented with NA/6HNA (6-hydroxynicotinic acid) as the sole carbon source and that complementation with intact restored the growth of the mutant strain.

Influence of (p)ppGpp on biofilm regulation in Pseudomonas putida KT2440.

The global regulatory molecule (p)ppGpp is synthesized under limited nutrition conditions and involves in many cellular processes in bacteria. (p)ppGpp has been reported to affect biofilm formation in several bacterial species. Here, we found that deletion of (p)ppGpp synthase genes of Pseudomonas putida KT2440 led to enhanced biofilm formation in polystyrene microtitre plates.

FleN and FleQ play a synergistic role in regulating lapA and bcs operons in Pseudomonas putida KT2440.

FleN generally functions as an antagonist of FleQ in regulating flagellar genes and biofilm matrix related genes in Pseudomonas aeruginosa. Here, we found that in Pseudomonas putida KT2440, FleN and FleQ play a synergistic role in regulating two biofilm matrix coding operons, lapA and bcs. FleN deletion decreased the transcription of lapA and increased the transcription of bcs operon, and the same trend was observed in fleQ deletion mutant before.

Nitrospira are more sensitive than Nitrobacter to land management in acid, fertilized soils of a rapeseed-rice rotation field trial.

Nitrite oxidation is recognized as an essential process of biogeochemical nitrogen cycling in agricultural ecosystems. How nitrite-oxidizing bacteria (NOB) respond to land managements (the effect from the long-term straw incorporation and environmental variability caused by the shift from the upland stage to the paddy stage) in a rapeseed-rice rotation field remains unclear. We found the nitrite oxidation (NO) in soils increased from the upland stage to the paddy stage.

Expression of the diguanylate cyclase GcbA is regulated by FleQ in response to cyclic di-GMP in Pseudomonas putida KT2440.

Cyclic di-GMP (c-di-GMP), a ubiquitous bacterial second messenger that regulates diverse cellular processes, is synthesized by diguanylate cyclase (DGC) and degraded by phosphodiesterase (PDE). GcbA is a well conserved DGC among Pseudomonas species, and has been reported to influence biofilm formation and flagellar motility in Pseudomonas fluorescens and Pseudomonas aeruginosa. Here we confirm the function of GcbA in Pseudomonas putida and reveal that expression of GcbA is regulated by FleQ in response to c-di-GMP.

Expression of the phosphodiesterase BifA facilitating swimming motility is partly controlled by FliA in Pseudomonas putida KT2440.

Flagella-mediated motility is an important capability of many bacteria to survive in nutrient-depleted and harsh environments. Decreasing the intracellular cyclic di-GMP (c-di-GMP) level by overexpression of phosphodiesterase BifA promotes flagellar-mediated motility and induces planktonic lifestyle in Pseudomonas. The mechanism that regulates expression of bifA gene was poorly studied.

C-di-GMP regulates the expression of lapA and bcs operons via FleQ in Pseudomonas putida KT2440.

Cyclic diguanylate (c-di-GMP) positively modulates the production of biofilm matrix components from the transcriptional to the post-translational level in a variety of bacterial species. However, mechanisms by which it regulates these opponents in Pseudomonas putida KT2440 remain unclear. Here we show that c-di-GMP regulates the adhesin LapA, LapF and exopolysaccharides Bcs, Pea at transcriptional level.