( 1999 )
Occurrence of Two Resin Acid-Degrading Bacteria and a Gene Encoding Resin Acid Biodegradation in Pulp and Paper Mill Effluent Biotreatment Systems Assayed by PCR.
PMID : 10441704 :
> Abstract We examined the distribution of two dehydroabietic acid-degrading bacteria, Pseudomonas abietaniphila BKME-9 and Zoogloea resiniphila DhA-35, in biotreatment systems for pulp and paper mill effluents (PPMEs) using PCR assays. These two bacteria were first isolated from two PPME biotreatment systems and can degrade both dehydroabietic acid (DhA) and other abietane resin acids. We also examined the distribution of a catabolic gene, ditA1, encoding the alpha subunit of an aromatic ring-hydroxylating dioxygenase involved in DhA degradation by BKME-9. PCR primers specific for the 16S rDNA of BKME-9 and of DhA-35 and specific for ditA1 were used. Among 3 laboratory- and 17 full-scale PPME biotreatment systems, 10 contained phylotype BKME-9, 3 contained phylotype DhA-35, and 11 contained ditA1, indicating the wider distribution of phylotype BKME-9 than of phylotype DhA-35. Both phylotype BKME-9 and ditA1 were detected in the biotreatment system from which BKME-9 was originally isolated in 1994, suggesting the persistance of BKME-9 in that biotreatment system. The detection limit of the PCR assay was one cell per PCR reaction, which corresponds to one BKME-9 cell per 6 x 10(7) total sludge bacteria. A competitive PCR assay indicated that ditA1 ranged from 51 to 250 copies/mg of dry biomass. BKME-9 appears to contribute to the biodegration of resin acids in some PPME biotreatment systems. Using degenerate PCR primers and touchdown PCR, we obtained from our DhA-degrading strain collection six DNA sequences putatively homologous to that of ditA1. Cluster analysis of these DNA sequences suggests that ditA1 encodes a representative of a novel class of dioxygenase enzymes.http://link.springer-ny.com/link/service/journals/00248/bibs/38n2p114.html
( 2007 )
Pseudomonas reinekei sp. nov., Pseudomonas moorei sp. nov. and Pseudomonas mohnii sp. nov., novel species capable of degrading chlorosalicylates or isopimaric acid.
PMID : 17473234 : DOI : 10.1099/ijs.0.64703-0
Three bacterial strains, designated MT1(T), RW10(T) and IpA-2(T), had been isolated previously for their ability to degrade chlorosalicylates or isopimaric acid. 16S rRNA gene sequence analysis demonstrated that these bacteria are related to species of the genus Pseudomonas. Analysis of the results of DNA-DNA hybridization with several close phylogenetic neighbours revealed a low level of hybridization (less than 57 %). On the basis of phenotypic characteristics, phylogenetic analysis, DNA-DNA relatedness data and chemotaxonomic analysis, it is concluded that these isolates represent separate novel species, for which the names Pseudomonas reinekei sp. nov. (type strain MT1(T) =DSM 18361(T)=CCUG 53116(T)), Pseudomonas moorei sp. nov. (type strain RW10(T) =DSM 12647(T)=CCUG 53114(T)) and Pseudomonas mohnii sp. nov. (type strain IpA-2(T) =DSM 18327(T)=CCUG 53115(T)) are proposed.
( 2007 )
Molecular detection and diversity of novel diterpenoid dioxygenase DitA1 genes from proteobacterial strains and soil samples.
PMID : 17472635 : DOI : 10.1111/j.1462-2920.2007.01242.x
Resin acids are tricyclic diterpenoids naturally synthesized by trees that are released from wood during pulping processes. Using a newly designed primer set, genes similar to that encoding the DitA1 catalytic alpha-subunit of the diterpenoid dioxygenase, a key enzyme in abietane resin acid degradation by Pseudomonas abietaniphila BKME-9, could be amplified from different Pseudomonas strains, whereas ditA1 gene sequence types representing distinct branches in the evolutionary tree were amplified from Burkholderia and Cupriavidus isolates. All isolates harbouring a ditA1-homologue were capable of growth on dehydroabietic acid as the sole source of carbon and energy and reverse transcription polymerase chain reaction analysis in three strains confirmed that ditA1 was expressed constitutively or in response to DhA, demonstrating its involvement in DhA-degradation. Evolutionary analyses indicate that gyrB (as a phylogenetic marker) and ditA1 genes have coevolved under purifying selection from their ancestral variants present in the most recent common ancestor of the genera Pseudomonas, Cupriavidus and Burkholderia. A polymerase chain reaction-single-strand conformation poylmorphism fingerprinting method was established to monitor the diversity of ditA1 genes in environmental samples. The molecular fingerprints indicated the presence ofa broad, previously unrecognized diversity of diterpenoid dioxygenase genes in soils, and suggest that other bacterial phyla may also harbour the genetic potential for DhA-degradation.
Ait Tayeb L,
( N/A )
Molecular phylogeny of the genus Pseudomonas based on rpoB sequences and application for the identification of isolates.
PMID : 15950132 : DOI : 10.1016/j.resmic.2005.02.009
Phylogenetic relationships within the genus Pseudomonas were examined by comparing partial (about 1000 nucleotides) rpoB gene sequences. A total of 186 strains belonging to 75 species of Pseudomonas sensu stricto and related species were studied. The phylogenetic resolution of the rpoB tree was approximately three times higher than that of the rrs tree. Ribogroups published earlier correlated well with rpoB sequence clusters. The rpoB sequence database generated by this study was used for identification. A total of 89 isolates (79.5%) were identified to a named species, while 16 isolates (14.3%) corresponded to unnamed species, and 7 isolates (6.2%) had uncertain affiliation. rpoB sequencing is now being used for routine identification of Pseudomonas isolates in our laboratory.
Nsigue Meilo S,
De Vos P,
( 2011 )
A long-branch attraction artifact reveals an adaptive radiation in pseudomonas.
PMID : 21504889 : DOI : 10.1093/molbev/msr099
A significant proportion of protein-encoding gene phylogenies in bacteria is inconsistent with the species phylogeny. It was usually argued that such inconsistencies resulted from lateral transfers. Here, by further studying the phylogeny of the oprF gene encoding the major surface protein in the bacterial Pseudomonas genus, we found that the incongruent tree topology observed results from a long-branch attraction (LBA) artifact and not from lateral transfers. LBA in the oprF phylogeny could be explained by the faster evolution in a lineage adapted to the rhizosphere, highlighting an unexpected adaptive radiation. We argue that analysis of such artifacts in other inconsistent bacterial phylogenies could be a valuable tool in molecular ecology to highlight cryptic adaptive radiations in microorganisms.
( 2013 )
Evaluation of oprI and oprL genes as molecular markers for the genus Pseudomonas and their use in studying the biodiversity of a small Belgian River.
PMID : 23246592 : DOI : 10.1016/j.resmic.2012.12.001
A multiplex PCR based on oprI and oprL, coding for the outer membrane lipoprotein I and the peptidoglycan-associated lipoprotein OprL, respectively, was developed for the detection of Pseudomonas strains from a bacterial collection isolated from a small river. To study the diversity of these Pseudomonas isolates, an oprI-oprL gene sequence database of 94 Pseudomonas type strains was constructed. Phylogenetic analysis of the concatenated oprI and oprL gene sequences of the Pseudomonas type strains showed that they were largely congruent with the classification based on the MLSA approach based on 16S rRNA, gyrB, rpoB and rpoD gene sequences of Mulet et al. in 2010. Identification of the isolates demonstrated a high diversity of Pseudomonas isolates at the source of the river located in a forest of which most isolates belonged to the Pseudomonas fluorescens lineage. On the other hand, the Pseudomonas population isolated at an anthropized site at the mouth of the river, receiving waste water from both households and industry, was very different and contained many Pseudomonas aeruginosa isolates.