Genome sequence analysis of Pseudomonas extremaustralis provides new insights into environmental adaptability and extreme conditions resistance

Abstract

The genome of the Antarctic bacterium Pseudomonas extremaustralis was analyzed searching for genes involved in environmental adaptability focusing on anaerobic metabolism, osmoregulation, cold adaptation, exopolysaccharide production and degradation of complex compounds. Experimental evidences demonstrated the functionality of several of these pathways, including arginine and pyruvate fermentation, alginate production and growth under cold conditions. Phylogenetic analysis along with genomic island prediction allowed the detection of genes with probable foreign origin such as those coding for acetate kinase, osmotic resistance and colanic acid biosynthesis. These findings suggest that in P. extremaustralis the horizontal transfer events and/or gene redundancy could play a key role in the survival under unfavorable conditions. Comparative genome analysis of these traits in other representative Pseudomonas species highlighted several similarities and differences with this extremophile bacterium.

Novel Essential Role of Ethanol Oxidation Genes at Low Temperature Revealed by Transcriptome Analysis in the Antarctic Bacterium Pseudomonas extremaustralis

“…Pseudomonas extremaustralis is a bacterium isolated from Antarctica [ 8 ] that shows high stress resistance connected to the production of high amounts of polyhydroxyalkanoates (PHA), mainly as polyhydroxybutyrate (PHB), a short chain length PHA but also is able to produce medium chain length PHA [ 9 ]. Genome analysis has revealed the presence of several fitness-related traits [ 10 ]. In this bacterium, PHB accumulation is essential for cold growth, freezing survival and important in oxidative stress resistance [ 11 ].…”

“…protegens Pf5, P . extremaustralis grows faster and reaches higher biomass yields at low temperatures [ 10 – 12 ]. Additionally, previous work has shown that micro-aerobic metabolism is relevant for this bacterium, and that the anaerobic global regulator, Anr, is involved in novel functions such as PHB metabolism, redox balance, oxidative stress resistance and biofilm development [ 13 – 15 ].…”

Studies on the biocontrol mechanisms of Pseudomonas graminis strain CPA-7 against food-borne pathogens in vitro and on fresh-cut melon

“…To assess the potential capacity of CPA-7 to adhere other surfaces, the production of alginate, reported as a matrix biofilm component of Pseudomonads such as P. aeruginosa, P. fluorescens, P. putida, P. syringae P. mendocina and P. extremaustralis (Govan, Fyfe, & Jarman, 1981;Raiger Iustman et al, 2014), was also quantified.…”

Living in an Extremely Polluted Environment: Clues from the Genome of Melanin-Producing Aeromonas salmonicida subsp. pectinolytica 34mel T

“…Nitrous oxide is a potent greenhouse gas emitted from soils and aquatic environments, including those exposed to anthropogenic activities, such as wastewater treatment plants. This compound can be produced both by nonbiological processes and as a result of nitrifying and denitrifying metabolism (85,86). A recent study identified nos genes in some Pseudomonas strains that are not able to carry out the complete conversion of nitrate to N 2 , and it has been proposed that in these bacteria these genes may have a role in the detoxification of nitrous oxide present in the environment (86).…”

“…This compound can be produced both by nonbiological processes and as a result of nitrifying and denitrifying metabolism (85,86). A recent study identified nos genes in some Pseudomonas strains that are not able to carry out the complete conversion of nitrate to N 2 , and it has been proposed that in these bacteria these genes may have a role in the detoxification of nitrous oxide present in the environment (86). A molecular assessment of the microbial diversity in the Matanza River showed a great abundance of potential denitrifiers (5), which are considered the main biological source of N 2 O.…”