Genome analysis of Pseudoalteromonas flavipulchra JG1 reveals various survival advantages in marine environment

Abstract

BackgroundCompetition between bacteria for habitat and resources is very common in the natural environment and is considered to be a selective force for survival. Many strains of the genus Pseudoalteromonas were confirmed to produce bioactive compounds that provide those advantages over their competitors. In our previous study, P. flavipulchra JG1 was found to synthesize a Pseudoalteromonas flavipulchra antibacterial Protein (PfaP) with L-amino acid oxidase activity and five small chemical compounds, which were the main competitive agents of the strain. In addition, the genome of this bacterium has been previously sequenced as Whole Genome Shotgun project (PMID: 22740664). In this study, more extensive genomic analysis was performed to identify specific genes or gene clusters which related to its competitive feature, and further experiments were carried out to confirm the physiological roles of these genes when competing with other microorganisms in marine environment.ResultsThe antibacterial protein PfaP may also participate in the biosynthesis of 6-bromoindolyl-3-acetic acid, indicating a synergistic effect between the antibacterial macromolecule and small molecules. Chitinases and quorum quenching enzymes present in P. flavipulchra, which coincide with great chitinase and acyl homoserine lactones degrading activities of strain JG1, suggest other potential mechanisms contribute to antibacterial/antifungal activities. Moreover, movability and rapid response mechanisms to phosphorus starvation and other stresses, such as antibiotic, oxidative and heavy metal stress, enable JG1 to adapt to deleterious, fluctuating and oligotrophic marine environments.ConclusionsThe genome of P. flavipulchra JG1 exhibits significant genetic advantages against other microorganisms, encoding antimicrobial agents as well as abilities to adapt to various adverse environments. Genes involved in synthesis of various antimicrobial substances enriches the antagonistic mechanisms of P. flavipulchra JG1 and affords several admissible biocontrol procedures in aquaculture. Furthermore, JG1 also evolves a range of mechanisms adapting the adverse marine environment or multidrug rearing conditions. The analysis of the genome of P. flavipulchra JG1 provides a better understanding of its competitive properties and also an extensive application prospect.

Disruption ofN‐acyl‐homoserine lactone‐specific signalling and virulence in clinical pathogens by marine sponge bacteria

“…With the exception of Psychrobacter , QSI activities (either enzymatic or small molecule) have been previously described for these organisms. However, studies on isolates associated with the marine environment are limited (Romero et al ., ; Yu et al ., ; Saurav et al ., ). Interestingly, as far as we know, this is the first description of a marine sponge Psychrobacter sp.…”

Distribution and diversity of bacterioplankton communities in subtropical seawater around Xiamen Island, China

“…phosphorus cycling, which might be one of the reason why bacterioplankton around Xiamen Island strongly correlated with nitrogen and phosphorus. For instance, ammonia-oxidizing bacteria (AOB) can be found in the Betaproteobacteria and Gammaproteobacteria (Purkhold et al 2000), most of nitrite-oxidizing bacteria (NOB) were affiliated Alphaproteobacteria (Cébron and Garnier 2005), denitrifying bacteria were usually found in Gamma-and Alphaproteobacteria (Carlson and Ingraham 1983), and bacterium from Pseudoalteromonas of Gammaproteobacteria had rapid response to phosphorus (Yu et al 2013). Moreover, nitrogen and phosphorus are also very important elements of bacterial nucleic acids (DNA, RNA) and proteins, therefore, it is reasonable that nitrogen and phosphorus showed significant influences on bacterial communities.…”

Chlorination or monochloramination: Balancing the regulated trihalomethane formation and microbial inactivation in marine aquaculture waters

“…Past genome sequencing of P. flavipulchra and P. tunicata revealed the presence of a large number of proteins (e.g. catalases, superoxide dismutase, alkyl hydroperoxide reductase) (Thomas et al, 2008;Yu et al, 2013) that may have been expressed in the presence of chlorination and/or monochloramination, and hence aided in overcoming oxidative stress.…”