Biomedical subjects

Peter Kämpfer

Publications and source records attributed to Peter Kämpfer.

At least 37 records · Page 2Linked to original sources

PubMed2006

Proposal of Hymenobacter norwichensis sp. nov., classification of 'Taxeobacter ocellatus', 'Taxeobacter gelupurpurascens' and 'Taxeobacter chitinovorans' as Hymenobacter ocellatus sp. nov., Hymenobacter gelipurpurascens sp. nov. and Hymenobacter chitinivorans sp. nov., respectively, and emended description of the genus Hymenobacter Hirsch et al. 1999.

Two airborne bacterial isolates, NS/2 and NS/50(T), were examined in order to determine their taxonomic position. Their almost complete 16S rRNA gene sequences shared 95.9 % similarity. Sequence comparisons demonstrated that their next relatives are species of the genus Hymenobacter (93.6-95.7 % similarity) and the strains 'Taxeobacter chitinovorans' Txc1(T), 'Taxeobacter gelupurpurascens' Txg1(T) and 'Taxeobacter ocellatus' Myx 2105(T) (90.5-96.4 %). Phylogenetic calculations indicated that these five strains together with the three recognized Hymenobacter species form a separate line of descent within the family 'Flexibacteraceae'. Isolates NS/2 and NS/50(T), as well as 'Taxeobacter chitinovorans' Txc1(T), 'Taxeobacter gelupurpurascens' Txg1(T) and 'Taxeobacter ocellatus' Myx 2105(T), possessed the characteristics of the genus Hymenobacter, the quinone system menaquinone MK-7 and a polyamine pattern with the major polyamine being sym-homospermidine. Each of the five strains had complex, unique polar lipid profiles, with phosphatidylethanolamine and several unknown aminophospho-, amino-, phospho-, glyco- and polar lipids of which several compounds were also found in established Hymenobacter species. All the strains studied possessed fatty acids characteristic of Hymenobacter species, including major acids iso-C(15 : 0), anteiso-C(15 : 0), C(16 : 1)omega5c, summed feature 3 (C(16 : 1)omega7c/iso-C(15 : 0) 2-OH) and summed feature 4 (iso-C(17 : 1) I/anteiso-C(17 : 1) B). The five strains could be distinguished from each other and from the three established species of the genus Hymenobacter based on relatively low 16S rRNA gene sequence similarities (<97 %), unique polar lipids and differing fatty acid profiles and physiological characteristics. In conclusion, the description of four novel species of the genus Hymenobacter appears to be justified, for which the names Hymenobacter norwichensis sp. nov. (type strain NS/50(T)=LMG 21876(T)=DSM 15439(T)), Hymenobacter chitinivorans sp. nov. (type strain Txc1(T)=LMG 21951(T)=DSM 11115(T)), Hymenobacter gelipurpurascens sp. nov. (type strain Txg1(T)=LMG 21874(T)=DSM [corrected][11116(T)) and Hymenobacter ocellatus sp. nov. (type strain Myx 2105(T)=Txo1(T)=LMG 21873(T)=DSM 11117(T)) are proposed. For strain NS/2, a description only is provided without proposal of a name because its status as a novel species was not demonstrated unambiguously.

Bacterial Typing Techniques↗

PubMed2006

Description of Wautersiella falsenii gen. nov., sp. nov., to accommodate clinical isolates phenotypically resembling members of the genera Chryseobacterium and Empedobacter.

A total of 26 isolates of non-fermenting, Gram-negative rods, obtained between 1980 and 2004 by various clinical laboratories in Belgium, with phenotypic characteristics resembling those of members of the genera Chryseobacterium and Empedobacter (indole-positive) and a biochemical profile resembling that of CDC group II-h, but urease-positive, were collected at the Université Catholique de Louvain Microbiology Laboratory, Belgium. The 16S rRNA gene sequences were determined for most of the isolates and showed 94-95 % similarity with the type strain of Empedobacter brevis as the closest relative, indicating that these isolates might belong to a separate genus. Furthermore, the 16S rRNA gene sequences of the isolates were similar, but two clusters (genomovars) could be distinguished. The sequence similarities were 99.5-100 % for the 14 isolates of genomovar 1 and 99.4-100 % for the 12 isolates of genomovar 2. The similarity between the two clusters was 98.3-99.5 %. The presence of two clearly different groups was corroborated by using tRNA intergenic length polymorphism analysis, which also enabled differentiation of the novel species from all other species studied thus far using this technique. DNA-DNA hybridization results excluded a close relatedness to Empedobacter brevis. The DNA G+C contents of the reference strains of genomovars 1 and 2 were 33.8+/-0.4 and 34.4+/-0.2 mol%, respectively. The name Wautersiella falsenii gen. nov., sp. nov., is proposed for this group, comprising two closely related genomovars. The type strain of the species and reference strain for genomovar 1 is NF 993(T) (=CCUG 51536(T)=CIP 108861(T)), which was isolated from a surgical wound. The reference strain for genomovar 2 is NF 770 (=CCUG 51537=CIP 108860), which was isolated from blood.

Bacterial Typing Techniques↗

PubMed2006

Valid publication of names of prokaryotes according to the rules of nomenclature: past history and current practice.

It is now 30 years since the concept of valid publication was introduced into prokaryote systematics in such a way that a system of registration/indexing was integrated. Despite the success of this system and the introduction of the Approved Lists of Bacterial Names, accompanied by a new starting date in prokaryote nomenclature, there is a need to review both the historical aspects and current practices so that the current generation of prokaryote systematists have an up-to-date overview of some of the key elements.

Bacteria↗

PubMed2006

Genotyping of Ochrobactrum anthropi by recA-based comparative sequence, PCR-RFLP, and 16S rRNA gene analysis.

A recA-PCR restriction fragment length polymorphism assay was developed to study intraspecies variation among Ochrobactrum anthropi. Primers deduced from the known recA gene sequence of the genetically closely related genus Brucella allowed the specific amplification of a 1065 bp recA fragment from each of the 38 O. anthropi and the eight Brucella strains investigated. RecA was also amplified from the type strains of O. intermedium, O. tritici, and O. lupini but could not be generated from O. grignonense and O. gallinifaecis. Subsequent comparative recA sequence- and HaeIII-recA restriction fragment length polymorphism analysis identified nine different genospecies among the tested 38 O. anthropi isolates, whereas the recA sequences of the Brucella spp. were indistinguishable. Furthermore, Brucella spp., O. anthropi, O. intermedium, and O. tritici were clearly separated from each other by means of their recA sequences and HaeIII restriction patterns. Five strains of uncertain species status listed in the Culture Collection University of Göteborg bacterial culture collection as O. anthropi were characterized by recA analysis, and their phylogenetic position within the Brucella-Ochrobactrum group was determined. In summary, recA-sequence analysis provides a new reliable molecular subtyping tool to study the phylogeny of the Ochrobactrum taxon at both the inter- and intraspecies level.

Animals↗

PubMed2005

Estimation of ribosomal RNA operon (rrn) copy number in Acinetobacter isolates and potential of patterns of rrn operon-containing fragments for typing strains of members of this genus.

The copy number of the rrn operon in 70 strains of Acinetobacter including the type strains of almost all the genomic species with validated names was estimated after digestion of their genomic DNA by the restriction enzymes BglII and PstI, and Southern blotting. Copy number estimates varied between and among species, with between 3 and 7 rrn operon copies detected. Copy number estimates obtained from the same strain with the two enzymes sometimes varied. BglII generated RFLP patterns of the rrn containing fragments obtained from Southern blots after agarose gel electrophoresis were examined for their value in identifying Acinetobacter isolates. This method was very reproducible with the same fragment pattern always generated from the same isolate on repeated analysis. Often multiple strains of the same genomic species gave identical or very similar patterns (e.g. Acinetobacter baylyi), clustering closest together on the dendrogram generated after numerical analysis of these patterns. However, with some, like BG5 and BG8, the patterns derived from the different strains, some of which had been placed in this genomic species from DNA:DNA hybridization data, varied considerably to each other and to the type strain. Little similarity was seen when relationships between these strains based on these patterns were compared to those using DNA:DNA hybridization data. Often these patterns could be used to question earlier identification of strains using phenotypic characters. Thus, strain AB82 thought to belong to genomic species 5 gave an identical pattern to A. bouvetii(T) (DSM 14964). In some cases this pattern analysis suggested that novel species of Acinetobacter might exist among the strains examined.

Acinetobacter↗

PubMed2005

Intraspecific comparative analysis of the species Salinibacter ruber.

Salinibacter ruber is the first extremely halophilic member of the Bacteria domain of proven environmental relevance in hypersaline brines at or approaching NaCl saturation, that has been brought to pure culture. A collection of 17 strains isolated from five different geographical locations (Mallorca, Alicante, Ebro Delta, Canary Islands, and Peruvian Andes) were studied following the currently accepted taxonomic approach. Additionally, random amplification of genomic DNA led to the phenetic analysis of the intraspecific diversity. Altogether the taxonomic study indicated that S. ruber remained highly homogeneous beyond any geographical barrier. However, genomic fingerprints indicated that populations from different isolation sites could still be discriminated.

Bacterial Physiological Phenomena↗

PubMed2005

Enterobacter radicincitans sp. nov., a plant growth promoting species of the family Enterobacteriaceae.

A plant growth promoting bacterial isolate (D5/23T) from the phyllosphere of winter wheat, able to fix atmospheric nitrogen and to produce auxines and cytokinins was investigated in a polyphasic taxonomy approach. Phylogenetic analyses using the 16S rRNA gene sequence of the strain clearly indicated that the strain belonged to the family Enterobacteriaceae, most closely related to Enterobacter cloacae with 99.0% and Enterobacter dissolvens with 98.5% sequence similarity. Phylogenetic analysis derived from the sequence of the rpoB gene showed the highest sequence similarities to Enterobacter cowanii (93.0%) but supported the distinct position of strain D5/23T. The isolate produced a fatty acid pattern typical for members of the family Enterobacteriaceae. On the basis of the phylogenetic analyses, DNA-DNA hybridizations, and the unique physiological and biochemical characteristics, we propose that strain D5/23T represents a new species of the genus Enterobacter for which we propose the name Enterobacter radicincitans sp. nov.

Bacterial Typing Techniques↗

PubMed2005

Hydrogenophaga defluvii sp. nov. and Hydrogenophaga atypica sp. nov., isolated from activated sludge.

Two Gram-negative, oxidase-positive rods (strains BSB 9.5T and BSB 41.8T) isolated from wastewater were studied using a polyphasic approach. 16S rRNA gene sequence comparisons demonstrated that both strains cluster phylogenetically within the family Comamonadaceae: the two strains shared 99.9 % 16S rRNA gene sequence similarity and were most closely related to the type strains of Hydrogenophaga palleronii (98.5 %) and Hydrogenophaga taeniospiralis (98.0 %). The fatty acid patterns and substrate-utilization profiles displayed similarity to the those of the five Hydrogenophaga species with validly published names, although clear differentiating characteristics were also observed. The two strains showed DNA-DNA hybridization values of 51 % with respect to each other. No close similarities to any other Hydrogenophaga species were detected in hybridization experiments with the genomic DNAs. On the basis of these results, two novel Hydrogenophaga species, Hydrogenophaga defluvii sp. nov. and Hydrogenophaga atypica sp. nov. are proposed, with BSB 9.5T (=DSM 15341T=CIP 108119T) and BSB 41.8T (=DSM 15342T=CIP 108118T) as the respective type strains.

Comamonadaceae↗

PubMed2005

Chryseobacterium formosense sp. nov., isolated from the rhizosphere of Lactuca sativa L. (garden lettuce).

A yellow-pigmented bacterial strain (CC-H3-2T), isolated from the rhizosphere of Lactuca sativa L. (garden lettuce) in Taiwan, was investigated using a polyphasic taxonomic approach. The cells were Gram-negative, rod-shaped and non-spore-forming. Phylogenetic analyses using the 16S rRNA gene sequence of the isolate indicated that the organism belongs to the genus Chryseobacterium, with the highest sequence similarity to the type strains of Chryseobacterium indoltheticum (97.7 %), Chryseobacterium scophthalmum (97.5 %), Chryseobacterium joostei (97.2 %) and Chryseobacterium defluvii (97.2 %). The major whole-cell fatty acids were iso-C(15 : 0) (52.2 %) and iso-C(17 : 0) 3-OH. DNA-DNA hybridization experiments revealed levels of only 27.4 % to C. scophthalmum, 27.1 % to C. indoltheticum, 14.1 % to C. joostei and 7.8 % to C. defluvii. DNA-DNA relatedness and biochemical and chemotaxonomic properties demonstrate that strain CC-H3-2T represents a novel species, for which the name Chryseobacterium formosense sp. nov. is proposed. The type strain is CC-H3-2T (=CCUG 49271T=CIP 108367T).

Bacterial Typing Techniques↗

PubMed2005

Malikia granosa gen. nov., sp. nov., a novel polyhydroxyalkanoate- and polyphosphate-accumulating bacterium isolated from activated sludge, and reclassification of Pseudomonas spinosa as Malikia spinosa comb. nov.

A Gram-negative, motile, rod-shaped bacterium, designated strain P1(T), was isolated from activated sludge of a municipal wastewater treatment plant. Phylogenetic analysis of its 16S rRNA gene sequence placed the novel isolate among representatives of the family Comamonadaceae. The closest relatives in reconstructed phylogenetic trees were Pseudomonas spinosa, Macromonas bipunctata and Hydrogenophaga species. Strain P1(T) was not able to grow anaerobically or autotrophically, reduced nitrate to nitrite and required vitamins for growth. Ubiquinone 8 (Q8) and 3-hydroxy-substituted fatty acids were present, but 2-hydroxy fatty acids were absent. The G+C content of the DNA was 67 mol%. Phenotypic characteristics allowed a clear differentiation of strain P1(T) from representatives of the genera Hydrogenophaga and Macromonas, whereas DNA-DNA hybridization experiments revealed that strain P1(T) did not belong to the species P. spinosa. As a peculiarity, cells of strain P1(T) and P. spinosa ATCC 14606(T) were able to accumulate large amounts of polyhydroxyalkanoates and polyphosphate in the form of large intracellular granules. Apparently in both strains nitrogen limitation stimulates the production of polyhydroxyalkanoates, whereas carbon starvation induces the formation of polyphosphates. Based upon phylogenetic and phenotypic evidence, it is proposed to establish the novel taxon Malikia granosa gen. nov., sp. nov., represented by the type strain P1(T) (=DSM 15619(T)=JCM 12706(T)=CIP 108194(T)). The most closely related species of strain P1(T) was P. spinosa. This species has been misclassified, and it is proposed to transfer it to the new genus Malikia as Malikia spinosa gen. nov., comb. nov. The type strain is ATCC 14606(T) (=DSM 15801(T)).

Comamonadaceae↗

PubMed2005

Nonomuraea kuesteri sp. nov.

A Gram-positive, aerobic, non-motile actinomycete, strain GW 14-1925(T), that formed branched substrate and aerial mycelium was studied using a polyphasic approach. On the basis of 16S rRNA gene sequence similarity studies, strain GW 14-1925(T) was shown to belong to the genus Nonomuraea, being most closely related to Nonomuraea longicatena (97.9 %), Nonomuraea turkmeniaca (98.9 %), Nonomuraea helvata (98.6 %), Nonomuraea polychroma (98.5 %), Nonomuraea salmonaea (98.3 %), Nonomuraea roseoviolacea subsp. roseoviolacea (98.1 %) and Nonomuraea roseoviolacea subsp. carminata (97.7 %). The 16S rRNA gene sequence similarity to other Nonomuraea species was <97.5 %. Chemotaxonomic data [major menaquinones of the MK-9 series with minor amounts of MK-8(H(4)); major polar lipids of phospholipid type IV; fatty acids with major amounts of iso- and anteiso- and 10-methyl-branched fatty acids in combination with iso-branched 2-hydroxy fatty acids] supported allocation of the strain to the genus Nonomuraea. The results of DNA-DNA hybridizations and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain GW 14-1925(T) from closely related species; thus, GW 14-1925(T) represents a novel species of the genus Nonomuraea, for which the name Nonomuraea kuesteri sp. nov. is proposed, with GW 14-1925(T) (=DSM 44753(T)=NRRL B-24325(T)) as the type strain.

Actinomycetales↗

PubMed2005

Novosphingobium lentum sp. nov., a psychrotolerant bacterium from a polychlorophenol bioremediation process.

A polychlorophenol-degrading strain, designated MT1(T), and three MT1-like strains, MT101, MT103 and MT104, were isolated from a cold (4-8 degrees C) fluidized-bed process treating chlorophenol-contaminated groundwater in southern Finland. The organisms were Gram-negative, rod-shaped, catalase-positive, non-spore-forming and non-motile. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strains belonged to the alpha-4 subclass of the Proteobacteria and were members of the genus Novosphingobium. The highest 16S rRNA gene sequence similarity observed for these strains was 96.5 % with the type strains of Novosphingobium hassiacum, Novosphingobium aromaticivorans and Novosphingobium subterraneum. Chemotaxonomic data (major ubiquinone: Q-10; major polyamine: spermidine; major polar lipids: phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and sphingoglycolipid; major fatty acids: 18 : 1omega7c, 16 : 1omega7c and 2-OH 14 : 0) as well as the ability to reduce nitrate supported the affiliation of the strains to the genus Novosphingobium. Based on the phylogenetic analysis, whole-cell fatty acid composition as well as biochemical and physiological characteristics, the MT1-like strains were highly similar and could be separated from all recognized Novosphingobium species. The novel species Novosphingobium lentum sp. nov. is proposed to accommodate strains MT1(T) (=DSM 13663(T)=CCUG 45847(T)), MT101 (=CCUG 45849), MT103 (=CCUG 45850) and MT104 (=CCUG 45851).

Bacterial Typing Techniques↗

PubMed2005

Pusillimonas noertemannii gen. nov., sp. nov., a new member of the family Alcaligenaceae that degrades substituted salicylates.

The taxonomic position of a Pseudomonas-like strain, designated BN9(T), was investigated. This strain had previously been isolated as a 5-aminosalicylate-degrading organism from a 6-aminonaphthalene-2-sulphonate-degrading mixed bacterial culture. Previously, detection of ubiquinone Q-8, a polyamine pattern with putrescine, spermidine and 2-hydroxyputrescine as the major polyamines, and partial 16S rRNA gene sequencing had suggested that strain BN9(T) belongs to the 'Betaproteobacteria'. This was supported by sequencing the 16S rRNA gene, which demonstrated 94-96 % sequence similarity to different species of the genera Achromobacter, Alcaligenes and Bordetella, and suggested that strain BN9(T) represents a member of the family Alcaligenaceae. Different methods for the construction of phylogenetic dendrograms placed the strain separately from all other genera within the Alcaligenaceae. Fatty acid analysis demonstrated the presence of high concentrations of C(19 : 0) cyclo omega8c. On the basis of low 16S rRNA gene sequence similarity to other members of the Alcaligenaceae, fatty acid and polar lipid profiles, and other unique phenotypic properties of strain BN9(T), the creation of a new genus and species with the name Pusillimonas noertemannii gen. nov., sp. nov. is proposed. The type strain is BN9(T) (= DSM 10065(T) = NCIMB 14020(T)).

Alcaligenaceae↗

PubMed2005

Chryseobacterium taichungense sp. nov., isolated from contaminated soil.

A bacterial strain (CC-TWGS1-8(T)) isolated from a tar-contaminated soil in Taiwan was studied in a detailed taxonomic study. The cells were Gram-negative, rod-shaped and non-spore-forming. Phylogenetic analyses using the 16S rRNA gene sequence of the strain clearly revealed an affiliation to the genus Chryseobacterium, the highest sequence similarities being to the type strain of Chryseobacterium indologenes (96.8 %), to Chryseobacterium gleum (96.8 %) and to Chryseobacterium joostei (96.4 %). The 16S rRNA gene sequence similarities to all other Chryseobacterium species were below 96 %. The major whole-cell fatty acids were 15 : 0 iso (35.4 %) and 17 : 0 iso 3OH (22.5 %). DNA-DNA hybridization values and the biochemical and chemotaxonomic properties demonstrate that strain CC-TWGS1-8(T) represents a novel species, for which the name Chryseobacterium taichungense sp. nov. is proposed. The type strain is CC-TWGS1-8(T) (= CCUG 50001(T) = CIP 108519(T)).

Bacterial Typing Techniques↗

PubMed2005

Bacillus herbersteinensis sp. nov.

Two bacterial strains, designated D-1,5a(T) and D-1,5b, were isolated from a medieval wall painting in the chapel of Castle Herberstein, Styria (Austria). The Gram-positive, heterotrophic, aerobic, spore-forming rods showed nearly identical whole-cell protein patterns, identical genomic fingerprints and identical physiological profiles, demonstrating their relationship at the species level. Both strains contained meso-diaminopimelic acid in their peptidoglycan, possessed a quinone system comprising menaquinone MK-7 and had fatty acid profiles in which C(15:0) iso and C(15:0) anteiso were predominant. The 16S rRNA gene sequence of D-1,5a(T) showed the highest similarity (99.5%) to the sequence of Bacillus sp. LMG 20243, and Bacillus flexus IFO 15715(T) was the next most closely related established species (96.5%). Other type strains, such as Bacillus fastidiosus DSM 91(T), Bacillus indicus SD/3(T), Bacillus cibi JG-30(T), Bacillus megaterium IAM 13418(T), Bacillus cohnii DSM 6308(T), Bacillus bataviensis LMG 21833(T) and Bacillus soli LMG 21838(T), shared 96.0-96.1% 16S rRNA gene sequence similarity with D-1,5a(T). The combination of physiological and chemotaxonomic traits distinguishes the two strains from those species sharing the highest sequence similarities (96.0-96.5%). On the basis of these characteristics and the phylogenetic position of strain D-1,5a(T) (=DSM 16534(T)=CCM 7228(T)), this strain is assigned as the type strain of a novel species of the genus Bacillus, for which the name Bacillus herbersteinensis sp. nov. is proposed.

Austria↗

PubMed2005

Aminobacter ciceronei sp. nov. and Aminobacter lissarensis sp. nov., isolated from various terrestrial environments.

The bacterial strains IMB-1(T) and CC495(T), which are capable of growth on methyl chloride (CH(3)Cl, chloromethane) and methyl bromide (CH(3)Br, bromomethane), were isolated from agricultural soil in California fumigated with CH(3)Br, and woodland soil in Northern Ireland, respectively. Two pesticide-/herbicide-degrading bacteria, strains ER2 and C147, were isolated from agricultural soil in Canada. Strain ER2 degrades N-methyl carbamate insecticides, and strain C147 degrades triazine herbicides widely used in agriculture. On the basis of their morphological, physiological and genotypic characteristics, these four strains are considered to represent two novel species of the genus Aminobacter, for which the names Aminobacter ciceronei sp. nov. (type strain IMB-1(T)=ATCC 202197(T)=CIP 108660(T)=CCUG 50580(T); strains ER2 and C147) and Aminobacter lissarensis sp. nov. (type strain CC495(T)=NCIMB 13798(T)=CIP 108661(T)=CCUG 50579(T)) are proposed.

Agriculture↗

PubMed2005

Description of two novel species, Sphingomonas abaci sp. nov. and Sphingomonas panni sp. nov.

Two Gram-negative, rod-shaped, non-spore-forming bacterial strains designated C42T and C52T were isolated in the Medical Clinic for Small Animals and Ungulates at the University for Veterinary Medicine Vienna, Austria. On the basis of 16S rRNA gene sequence similarity, both strains were shown to belong to the genus Sphingomonas. Strain C42T showed the greatest levels of sequence similarity with Sphingomonas melonis DSM 14444T and Sphingomonas aquatilis KCTC 2881T (both 97.7 %). Strain C52T showed the greatest levels of sequence similarity with Sphingomonas koreensis KCTC 2882T (97.2 %), Sphingomonas aquatilis KCTC 2881T (97.1 %) and S. melonis DSM 14444T (97.0 %). The presence of Q-10 as the main ubiquinone, the predominance of the compound sym-homospermidine in the polyamine patterns, the presence of a Sphingomonadaceae-specific sphingoglycolipid in the polar lipid patterns, the presence of the fatty acid 2-OH C(14 : 0) and the lack of 3-hydroxy fatty acids supported the identification of the two novel strains as members of the genus Sphingomonas sensu stricto. Unique physiological characteristics, protein patterns, quantitative differences in their fatty acid profiles and the results of genomic fingerprinting and DNA-DNA hybridizations differentiated strains C42T and C52T from closely related Sphingomonas species. Hence, the two strains are described as novel species of the genus Sphingomonas sensu stricto. The names Sphingomonas abaci sp. nov. (type strain C42T=LMG 21978T=DSM 15867T) and Sphingomonas panni sp. nov. (type strain C52T=LMG 21979(T)=DSM 15761T) are proposed.

DNA, Bacterial↗

PubMed2005

Extensive diversity of ionizing-radiation-resistant bacteria recovered from Sonoran Desert soil and description of nine new species of the genus Deinococcus obtained from a single soil sample.

The ionizing-radiation-resistant fractions of two soil bacterial communities were investigated by exposing an arid soil from the Sonoran Desert and a nonarid soil from a Louisiana forest to various doses of ionizing radiation using a (60)Co source. The numbers of surviving bacteria decreased as the dose of gamma radiation to which the soils were exposed increased. Bacterial isolates surviving doses of 30 kGy were recovered from the Sonoran Desert soil, while no isolates were recovered from the nonarid forest soil after exposure to doses greater than 13 kGy. The phylogenetic diversities of the surviving culturable bacteria were compared for the two soils using 16S rRNA gene sequence analysis. In addition to a bacterial population that was more resistant to higher doses of ionizing radiation, the diversity of the isolates was greater in the arid soil. The taxonomic diversity of the isolates recovered was found to decrease as the level of ionizing-radiation exposure increased. Bacterial isolates of the genera Deinococcus, Geodermatophilus, and Hymenobacter were still recovered from the arid soil after exposure to doses of 17 to 30 kGy. The recovery of large numbers of extremely ionizing-radiation-resistant bacteria from an arid soil and not from a nonarid soil provides further ecological support for the hypothesis that the ionizing-radiation resistance phenotype is a consequence of the evolution of other DNA repair systems that protect cells against commonly encountered environmental stressors, such as desiccation. The diverse group of bacterial strains isolated from the arid soil sample included 60 Deinococcus strains, the characterization of which revealed nine novel species of this genus.

DNA, Bacterial↗