| a polyhydroxybutyrate-producing pseudomonas sp. isolated from antarctic environments with high stress resistance. | pseudomonas sp. 14-3, a strain that accumulates large quantities of polyhydroxybutyrate (phb) when grown on octanoate, was isolated from antarctic environments. this isolate was characterized on the basis of phenotypic features and partial sequencing of its 16s ribosomal rna gene. pseudomonas sp. 14-3 showed increased tolerance to both thermal and oxidative stress compared with three other pseudomonas species. stress tolerance of pseudomonas sp. 14-3 was analyzed in polyhydroxyalkanoate accumula ... | 2004 | 15386099 |
| impaired polyhydroxybutyrate biosynthesis from glucose in pseudomonas sp. 14-3 is due to a defective beta-ketothiolase gene. | pseudomonas sp. 14-3 accumulates polyhydroxybutyrate (phb) from octanoate, but not from glucose. to elucidate this unusual phenotype, genes responsible for the synthesis of phb were cloned and analyzed. a phb polymerase gene (phac) was found downstream from genes coding for a beta-ketothiolase (phaa), an acetoacetyl-coenzyme a reductase (phab) and a putative transcriptional regulator (phar). all genes were similar to pha genes from several related species, but differences were observed in the di ... | 2006 | 17020558 |
| polyhydroxyalkanoates are essential for maintenance of redox state in the antarctic bacterium pseudomonas sp. 14-3 during low temperature adaptation. | polyhydroxyalkanoates (phas) are highly reduced bacterial storage compounds that increase fitness in changing environments. we have previously shown that pharbac genes from the antarctic bacterium pseudomonas sp. 14-3 are located in a genomic island containing other genes probably related with its adaptability to cold environments. in this paper, pseudomonas sp. 14-3 and its pha synthase-minus mutant (phac) were used to asses the effect of pha accumulation on the adaptability to cold conditions. ... | 2009 | 18931822 |
| ecology and characterization of polyhydroxyalkanoate-producing microorganisms on and in plants. | polyhydroxyalkanoates are energy reserve polymers produced by bacteria to survive periods of starvation in natural habitats. little is known about the ecology of polyhydroxyalkanoate-producing bacteria. to analyse the occurrence of this specific group on/in seven different plant species, a combined strategy containing culture-dependent and -independent methods was applied. using microbial fingerprint techniques (single-strand conformation polymorphism analysis with specific primers for phac gene ... | 2009 | 19656194 |
| oxygen-sensitive global regulator, anr, is involved in the biosynthesis of poly(3-hydroxybutyrate) in pseudomonas extremaustralis. | we analyzed the influence of the redox global regulator anr on the accumulation of poly(3-hydroxybutyrate) (phb) in pseudomonas extremaustralis. anr regulates a set of genes in the aerobic-anaerobic transition including genes involved in nitrate reduction and arginine fermentation. an anr mutant was constructed using pcr-based strategies. the wild-type strain was able to grow in both microaerobic and anaerobic conditions using nitrate as the terminal electron acceptor while the mutant strain was ... | 2010 | 21042031 |
| poly(3-hydroxybutyrate) influences biofilm formation and motility in the novel antarctic species pseudomonas extremaustralis under cold conditions. | polyhydroxyalkanoates (phas) are highly reduced bacterial storage compounds that increase fitness in changing environments. it has previously shown that polyhydroxybutyrate (phb) accumulation is essential during the growth under cold conditions. in this work, the relationship between phb accumulation and biofilm development at low temperature was investigated. p. extremaustralis, an antarctic strain able to accumulate phb, and its phac mutant, impaired in the synthesis of this polymer, were used ... | 2011 | 21667094 |
| novel essential role of ethanol oxidation genes at low temperature revealed by transcriptome analysis in the antarctic bacterium pseudomonas extremaustralis. | temperature is one of the most important factors for bacterial growth and development. cold environments are widely distributed on earth, and psychrotolerant and psychrophilic microorganisms have developed different adaptation strategies to cope with the stress derived from low temperatures. pseudomonas extremaustralis is an antarctic bacterium able to grow under low temperatures and to produce high amounts of polyhydroxyalkanoates (phas). in this work, we analyzed the genome-wide transcriptome ... | 2015 | 26671564 |
| high polyhydroxybutyrate production in pseudomonas extremaustralis is associated with differential expression of horizontally acquired and core genome polyhydroxyalkanoate synthase genes. | pseudomonas extremaustralis produces mainly polyhydroxybutyrate (phb), a short chain length polyhydroxyalkanoate (sclpha) infrequently found in pseudomonas species. previous studies with this strain demonstrated that phb genes are located in a genomic island. in this work, the analysis of the genome of p. extremaustralis revealed the presence of another phb cluster phbfpx, with high similarity to genes belonging to burkholderiales, and also a cluster, phac1zc2d, coding for medium chain length ph ... | 2014 | 24887088 |
| diversity of small rnas expressed in pseudomonas species. | rna sequencing (rna-seq) has revealed several hundreds of previously undetected small rnas (srnas) in all bacterial species investigated, including strains of pseudomonas aeruginosa, pseudomonas putida and pseudomonas syringae. nonetheless, only little is known about the extent of conservation of expressed srnas across strains and species. in this study, we have used rna-seq to identify srnas in p. putida dot-t1e and pseudomonas extremaustralis 14-3b. this is the first strain of p. extremaustral ... | 2015 | 25394275 |
| genome sequence analysis of pseudomonas extremaustralis provides new insights into environmental adaptability and extreme conditions resistance. | 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 isl ... | 2015 | 25316211 |
| the global anaerobic regulator anr, is involved in cell attachment and aggregation influencing the first stages of biofilm development in pseudomonas extremaustralis. | pseudomonas extremaustralis is a versatile antarctic bacterium, able to grow under microaerobic and anaerobic conditions and is related to several non-pathogenic pseudomonads. here we report on the role of the global anaerobic regulator anr, in the early steps of p. extremaustralis biofilm development. we found that the anr mutant was reduced in its ability to attach, to form aggregates and to display twitching motility but presented higher swimming motility than the wild type. in addition, micr ... | 2013 | 24146909 |
| anr, the anaerobic global regulator, modulates the redox state and oxidative stress resistance in pseudomonas extremaustralis. | the role of anr in oxidative stress resistance was investigated in pseudomonas extremaustralis, a polyhydroxybutyrate-producing antarctic bacterium. the absence of anr caused increased sensitivity to hydrogen peroxide under low oxygen tension. this phenomenon was associated with a decrease in the redox ratio, higher oxygen consumption and higher reactive oxygen species production. physiological responses of the mutant to the oxidized state included an increase in nadp(h) content, catalase activi ... | 2013 | 23223440 |
| genome sequence of the polyhydroxybutyrate producer pseudomonas extremaustralis, a highly stress-resistant antarctic bacterium. | pseudomonas extremaustralis 14-3b presents genes involved in the synthesis of different polyhydroxyalkanoates, in tolerance and degradation of pollutants, and in microaerobic metabolism. several genomic islands were detected. genetic machinery could contribute to the adaptability to stressful conditions. this is the first genome sequence reported from a pseudomonas isolated from cold environments. | 2012 | 22493195 |
| biofilm lifestyle enhances diesel bioremediation and biosurfactant production in the antarctic polyhydroxyalkanoate producer pseudomonas extremaustralis. | diesel is a widely distributed pollutant. bioremediation of this kind of compounds requires the use of microorganisms able to survive and adapt to contaminated environments. pseudomonas extremaustralis is an antarctic bacterium with a remarkable survival capability associated to polyhydroxyalkanoates (phas) production. this strain was used to investigate the effect of cell growth conditions--in biofilm versus shaken flask cultures--as well as the inocula characteristics associated with phas accu ... | 2012 | 22302594 |
| pseudomonas extremaustralis sp. nov., a poly(3-hydroxybutyrate) producer isolated from an antarctic environment. | a gram-negative, mobile, rod-shaped, non-spore-forming bacterium (strain 14-3(t)) was isolated from a temporary pond in antarctica. on the basis of 16s rrna gene sequence similarity, strain 14-3(t) was shown to belong to the genus pseudomonas sensu stricto. physiological and biochemical tests supported the phylogenetic affiliation. strain 14-3(t) is closely related to pseudomonas veronii dsm 11331(t), sharing 99.7% sequence similarity. dna-dna hybridization experiments between the two strains sh ... | 2009 | 19688380 |
| the polyhydroxyalkanoate genes of a stress resistant antarctic pseudomonas are situated within a genomic island. | pseudomonas sp. 14-3 is an antarctic bacterium that shows high stress resistance in association with high polyhydroxybutyrate (phb) production. in this paper genes involved in phb biosynthesis (pharbac) were found within a genomic island named pha-gi. numerous mobile elements or proteins associated with them, such as an integrase, insertion sequences, a bacterial group ii intron, a complete type i protein secretion system and incp plasmid-related proteins were detected among the 28 orfs identifi ... | 2007 | 17629557 |