ABSTRACT
Pseudomonas putida is a metabolically versatile saprophytic soil bacterium that has been certified as a biosafety host for the cloning of foreign genes. The bacterium also has considerable potential for biotechnological applications. Sequence analysis of the 6.18 Mb genome of strain KT2440 reveals diverse transport and metabolic systems. Although there is a high level of genome conservation with the pathogenic Pseudomonad Pseudomonas aeruginosa (85% of the predicted coding regions are shared), key virulence factors including exotoxin A and type III secretion systems are absent. Analysis of the genome gives insight into the non-pathogenic nature of P. putida and points to potential new applications in agriculture, biocatalysis, bioremediation and bioplastic production.
Subject(s)
Energy Metabolism , Genome, Bacterial , Open Reading Frames/genetics , Pseudomonas putida/genetics , Bacterial Proteins/genetics , Base Sequence , Genes, Bacterial/genetics , Molecular Sequence Data , Phylogeny , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/metabolism , Pseudomonas putida/metabolismABSTRACT
A physical mapping strategy has been developed to verify and accelerate the assembly and gap closure phase of a microbial genome shotgun-sequencing project. The protocol was worked out during the ongoing Pseudomonas putida KT2440 genome project. A macro-restriction map was constructed by linking probe hybridisation of SwaI- or I-CeuI-restricted chromosomes to serve as a backbone for the quick quality control of sequence and contig assemblies. The library of PCR-generated SwaI linking probes was derived from the sequence assembly after 3- and 6-fold genome coverage. In order to support gap closure in regions with ambiguous assemblies such as the repetitive sequence of the seven ribosomal operons, high-resolution Smith/Birnstiel maps were generated by Southern hybridisation of pulsed-field gel electrophoresis-separated rare-cutter complete/frequent-cutter partial digestions with rare-cutter fragment end probes. Overall 1.5 Mb of the 6.1 Mb P.putida KT2440 genome has been subjected to high-resolution physical mapping in order to align assemblies generated from shotgun sequencing.
Subject(s)
DNA, Bacterial/genetics , Genome, Bacterial , Pseudomonas putida/genetics , Restriction Mapping/methods , DNA, Bacterial/chemistry , DNA, Bacterial/metabolism , Deoxyribonucleases, Type II Site-Specific/metabolism , Electrophoresis, Gel, Pulsed-Field , Endodeoxyribonucleases/metabolism , RNA, Ribosomal/genetics , Sequence Analysis, DNA/methods , rRNA Operon/geneticsABSTRACT
Comparative sequencing of Pseudomonas aeruginosa genes oriC, citS, ampC, oprI, fliC, and pilA in 19 environmental and clinical isolates revealed the sequence diversity to be about 1 order of magnitude lower than in comparable housekeeping genes of Salmonella. In contrast to the low nucleotide substitution rate, the frequency of recombination among different P. aeruginosa genotypes was high, leading to the random association of alleles. The P. aeruginosa population consists of equivalent genotypes that form a net-like population structure. However, each genotype represents a cluster of closely related strains which retain their sequence signature in the conserved gene pool and carry a set of genotype-specific DNA blocks. The codon adaptation index, a quantitative measure of synonymous codon bias of genes, was found to be consistently high in the P. aeruginosa genome irrespective of the metabolic category and the abundance of the encoded gene product. Such uniformly high codon adaptation indices of 0.55 to 0.85 fit the ubiquitous lifestyle of P. aeruginosa.
Subject(s)
Biological Evolution , Genetic Variation , Genome, Bacterial , Pseudomonas aeruginosa/genetics , Deoxyribonucleases, Type II Site-Specific , Genes, Bacterial , Genetic Code , Genotype , Restriction Mapping , Sequence Analysis, DNA , Species SpecificityABSTRACT
Perceptions of work interfering with family life and family issues interfering with work are examined as 2 distinct constructs representing work-family conflict. Experienced work-family conflict is argued to reduce one's value attainment which, in turn, lowers both job and life satisfaction. This study examines value attainment as a mediating variable in the work-family conflict and satisfaction relationship. Responses from 270 hotel managers indicate that value attainment either partially or fully mediates the relationship between work interference with family and family interference with work and both job and life satisfaction. Value attainment is argued to be a meaningful explanatory variable for the negative relationship between work-family conflict and job-life satisfaction.
Subject(s)
Job Satisfaction , Quality of Life , Social Values , Workload , Adult , Family Relations , Female , Humans , Male , Middle Aged , Stress, Psychological , WorkplaceABSTRACT
Cystic fibrosis is a severe monogenic disorder of ion transport in exocrine glands. The basic defect predisposes to chronic bacterial airway infections with Staphylococcus aureus, Haemophilus influenzae, Pseudomonas aeruginosa and Burkholderia cepacia. The Pseudomonas infections in cystic fibrosis are a paradigm of how versatile environmental bacteria can conquer, adapt and persist in an atypical habitat and successfully evade defence mechanisms and chemotherapy in a susceptible host. Regular chemotherapy with aerosol and systemic antipseudomonal drugs has improved the course and prognosis of the disease, and research for effective vaccines is on the way.
