Isolation and characterisation of Thiobacillus halophilus sp. nov., a sulphur-oxidising autotrophic eubacterium from a Western Australian hypersaline lake

The isolation of a novel obligately chemolithotrophic, halophilic and extremely halotolerant Thiobacillus from a hypersaline lake is described. Attempts to demonstrate sulphur- and ferrous iron-oxidizing chemolithotrophs in neighbouring hypersaline lakes were unsuccessful. The organism isolated differs from any other Thiobacillus species previously described and is formally named as Thiobacillus halophilus. It possesses ribulose bisphosphate carboxylase and grows chemolithoautotrophically on thiosulphate, tetrathionate and sulphur, oxidising them to sulphate. Kinetic constants for oxidation of sulphide, thiosulphate, trithionate and tetrathionate are presented. The organism is obligately halophilic, growing best with 0.8–1.0 M NaCl, and tolerating up to 4 M NaCl. Optimum growth was obtained at about 30° C and pH 7.0–7.3. It contains ubiquinone Q-8 and its DNA contains 45 mol % G+C. Organisms of this type might contribute significantly to the autotrophic fixation of carbon dioxide in some hypersaline extreme environments of the kind described.     

Isolation and physiological characterisation of Thiobacillus thyasiris sp. nov., a novel marine facultative autotroph and the putative symbiont of Thyasira flexuosa

A novel facultatively chemolithoautotropic Thiobacillus, isolated from the gill tissue of the marine bivalve Thyasira flexuosa, is described. It is believed to be the symbiont from this animal, providing the animal with carbon fixed by the Calvin cycle. The organism grows lithoautotrophically on thiosulphate, tetrathionate and elemental sulphur, which are oxidised to sulphate. It oxidizes sulphide, thiosulphate, trithionate, tetrathionate and hexathionate, but not thiocyanate. Kinetic constants for these substrates are presented. In autotrophic batch culture it produces yields that are among the lowest reported for thiosulphate or tetrathionate as energy substrates (1.25 and 2.5 g cell-carbon per mol substrate, respectively). Autotrophic cultures contain ribulose bisphosphate carboxylase and excreted 20% of their fixed carbon into the medium during growth. Mixotrophic growth on acetate and thiosulphate resulted in partial repression of the carboxylase. The organism is slightly halophilic and markedly halotolerant, showing optimum growth at about pH 7.5 and maximum growth rate at 37° C. It contains ubiquinone Q-10 and its DNA contains 52 mol % G+C. These characteristics distinguish it from any other Thiobacillus or Thiomicrospira species previously described. The organism is formally described and named as Thiobacillus thyasiris.     

Isolation and characterization of Thiobacillus hydrothermalis sp. nov., a mesophilic obligately chemolithotrophic bacterium isolated from a deep-sea hydrothermal vent in Fiji Basin

A novel obligately chemolithotrophic Thiobacillus species isolated from a deep-sea hydrothermal vent is described. This organism grows lithoautotrophically on thiosulphate, tetrathionate, sulphide and sulphur which are oxidized to sulphate. The isolate is slightly halophilic and markedly halotolerant, showing optimum growth at pH 7.5 and at 35°C. The G+C content of the DNA is 67.1 mol%. The 16S rRNA sequence is distinct from any other Thiobacilli sequences. Phylogenetic analysis shows the organism to be a representative of the -group of proteobacteria and a specific relative of Thiobacillus neapolitanus. The ubiquinone is ubiquinone-8. These characters distinguish the isolate from any other Thiobacillus or Thiomicrospira species previously reported and is a new species described as Thiobacillus hydrothermalis. The type strain is isolate R3, DSM7121.     

Chemolithotrophic metabolism of the newly-isolated moderately thermophilic,obligately autotrophic Thiobacillus tepidarius

Thiobacillus tepidarius, isolated from the hot springs at Bath, Avon, UK, grew optimally at 43–45°C and pH 6.0–7.5 on thiosulphate or tetrathionate. In batch culture, thiosulphate was oxidized stoichiometrically to tetrathionate, with a rise in pH. The tetrathionate was then oxidized to sulphate, supporting growth and producing a fall in pH to a minimum of ph 4.8. The organism contained high levels of thiosulphate-oxidizing enzyme, rhodanese and ribulose bisphosphate carboxylase. It was obligately chemolithotrophic and autotrophic. In chemostat culture, T. tepidarius grew autotrophically with the following sole energy-substrates: sulphide, thiosulphate, trithionate, tetrathionate, hexathionate or heptathionate. Thiocyanate, dithionate and sulphite were not used as sole substrates, although sulphite enhanced growth yields in the presence of thiosulphate. Maximum specific growth rate on tetrathionate was 0.44 h^-1. True growth yields (Y _max) and maintenance coefficients (m) were calculated for sulphide, thiosulphate, trithionate and tetrathionate and observed yields at a single fixed dilution rate compared with those on hexathionate and heptathionate. Mean values for Y _max, determined from measurements of absorbance, dry wt, total organic carbon and cell protein, were similar for sulphide, thiosulphate and trithionate (10.9 g dry wt/mol substrate) as expected from their equivalent oxygen consumption for oxidation. Y _max for tetrathionate (20.5) and the relative Y _o values (as g dry wt/g atom oxygen consumed) for thiosulphate and all four polythionates indicated that substrate level phosphorylation did not contribute significantly to energy conservation. These Y _max values were 40–70% higher than any of those previously reported for obligately aerobic thiobacilli. Mean values for m were 6.7 mmol substrate oxidized/g dry wt·h for sulphide, thiosulphate and trithionate, and 2.6 for tetrathionate.Abbreviation PIPES Piperazine-N,N-bis(ethane sulphonic acid)     

Citeromyces cibodasensis sp. nov., a novel yeast species isolated from leaf litter in Indonesia

A novel yeast species was isolated from leaf litter of Macropanax dispermus obtained from the Cibodas Botanical Garden, West Java, Indonesia. The two strains of the species displayed typical characteristics of the genus Citeromyces. Phylogenetic analysis based on the gene sequences of the D1/D2 domains of large subunit (LSU) rDNA, internal transcribed spacer (ITS) including 5.8S rDNA, mitochondrial small-subunit rRNA gene (MtSm), and translation elongation factor-1α (EF-1α) showed that the novel strains were clearly separated from the other four existing species of the genus Citeromyces. Therefore, the two strains were proposed to represent a novel species within the genus Citeromyces, for which the name Citeromyces cibodasensis is proposed; the type strain is NBRC 110244^T (= CBS 14272^T?=?InaCCY703^T?=?AK 01).     

Energetics of mixotrophic and autotrophic C1-metabolism by Thiobacillus acidophilus

Although the facultatively autotrophic acidophile Thiobacillus acidophilus is unable to grow on formate and formaldehyde in batch cultures, cells from glucose-limited chemostat cultures exhibited substrate-dependent oxygen uptake with these C₁-compounds. Oxidation of formate and formaldehyde was uncoupler-sensitive, suggesting that active transport was involved in the metabolism of these compounds. Formate- and formaldehyde-dependent oxygen uptake was strongly inhibited at substrate concentrations above 150 and 400 M, respectively. However, autotrophic formate-limited chemostat cultures were obtained by carefully increasing the formate to glucose ratio in the reservoir medium of mixotrophic chemostat cultures. The molar growth yield on formate (Y=2.5 g ·mol^-1 at a dilution rate of 0.05 h^-1) and RuBPCase activities in cell-free extracts suggested that T. acidophilus employs the Calvin cycle for carbon assimilation during growth on formate. T. acidophilus was unable to utilize the C₁-compounds methanol and methylamine. Formate-dependent oxygen uptake was expressed constitutively under a variety of growth conditions. Cell-free extracts contained both dye-linked and NAD-dependent formate dehydrogenase activities. NAD-dependent oxidation of formaldehyde required reduced glutathione. In addition, cell-free extracts contained a dye-linked formaldehyde dehydrogenase activity. Mixotrophic growth yields were higher than the sum of the heterotrophic and autotrophic yields. A quantitative analysis of the mixotrophic growth studies revealed that formaldehyde was a more effective energy source than formate.     

Mixotrophic and autotrophic growth of Thiobacillus acidophilus on tetrathionate

Thiobacillus acidophilus can grow in batch and chemostat culture as a heterotroph on glucose, a chemolithoautotroph on tetrathionate and CO₂, or as a mixotroph. Mixotrophically it obtains energy from the simultaneous oxidation of tetrathionate and glucose, and carbon from both glucose and CO₂. Mixotrophic cultures contain lower activities of ribulose 1,5-bisphosphate carboxylase and exhibit lower specific rates of tetrathionate oxidation than do autotrophic cultures. Mixotrophic cultures with low concentrations of glucose have growth rates that are intermediate between slow autotrophic growth and fast heterotrophic growth. Slightly more glucose-carbon is assimilated by mixotrophic cultures than by heterotrophic ones provided with the same concentrations of glucose. Mixotrophic yield in the chemostat is also slightly greater than predicted from autotrophic and heterotrophic yields. These observations indicate that there is preferential assimilation of glucose, at the expense of energy from tetrathionate oxidation, during mixotrophy, resulting in an overall energy saving that produces enhanced growth yield. These observations are relevant to understanding the regulatory behaviour of T. acidophilus in its acidic, mineral-leaching habitats.     

Isolation and characterization of a novel facultatively alkaliphilic bacterium,Corynebacterium sp., grown on n-alkanes

A novel facultatively alkaliphilic bacterium that grows on a chemically defined medium containing n-alkanes as the sole carbon source was isolated from soil. The isolate was obligately aerobic, non-motile, gram-positive, and formed metachromatic granules. It was not acidfast and did not form endospores. The cell wall contained meso-diaminopimelic acid, arabinose, and galactose; the glycan moiety of the cell wall contained acetyl residues. The bacterium was catalase-positive, oxidasenegative, and the G+C content of DNA was 70.8 mol%. According to these tests, the isolate was assigned to the genus Corynebacterium. The bacterium grew well between pH 6.2 to 10.2 and the doubling time in this pH range was 4–6 h. For the growth of the isolate, added Na⁺ in the culture medium stimulated growth, but was not indispensable at both pH 7.2 and pH 10.2. In addition to hydrocarbons, the isolate was able to grow on a chemically defined medium containing acetate, glucose, or fructose as the sole carbon source. Analysis of reduced minus oxidized difference spectra of whole cells showed that the bacterium only possessed less than one tenth the amount of total cytochromes as compared with Bacillus alcalophilus. The above results sugest that the bacterium has characteristics different than those of the alkaliphilic Bacillus previously described.     

Description of four novel species of Xenorhabdus, family Enterobacteriaceae: Xenorhabdus budapestensis sp. nov., Xenorhabdus ehlersii sp. nov., Xenorhabdus innexi sp. nov., and Xenorhabdus szentirmaii sp. nov

The taxonomic affiliation was determined for four Xenorhabdus strains isolated from four Steinernema hosts from different countries. As compared to the five validly described Xenorhabdus species, i.e., X. nematophila, X. japonica, X. beddingii, X. bovienii and X. poinarii, these isolates represented novel species on the basis of 16S rRNA gene sequences and riboprint patterns, as well as by physiological and metabolic properties. They were named Xenorhabdus budapestensis sp. nov., type strain DSM 16342^T, isolated from Steinernema bicornutum; Xenorhabdus ehlersii sp. nov., type strain DSM 16337^T, isolated from Steinernema serratum; Xenorhabdus innexi sp. nov., type strain DSM 16336^T isolated from Steinernema scapterisci; and Xenorhabdus szentirmaii sp. nov., type strain DSM 16338^T, isolated from Steinernema rarum.     

Thiobacillus plumbophilus spec. nov., a novel galena and hydrogen oxidizer

From an uranium mine three strains of rodshaped, mesophilic, chemolithoautotrophic bacteria were isolated. They grow by oxidation of H₂S, galena (PbS) and H₂. Anglesite (PbSO₄) is formed from galena. No ferrous iron is oxidized by the isolates. They grow between pH 4 and 6.5 at temperatures of about 9 to 41°C (optimum around 27°C). The G+C content of the DNA is around 66 mol %. Based on their ability to oxidize sulfur compounds, the new organisms belong to the genus Thiobacillus. No significant homology with Thiobacillus ferrooxidans and Thiobacillus cuprinus was detected by DNA-DNA hybridization. Therefore the new isolates represent a new species within the genus Thiobacillus. Based on the unusual growth on galena, we name the new species Thiobacillus plumbophilus (type strain Gro 7; DSM 6690).     

Four novel yeasts from decaying organic matter: Blastobotrys robertii sp. nov., Candida cretensis sp. nov., Candida scorzettiae sp. nov. and Candida vadensis sp. nov

Four novel yeast species are described, two from decaying mushrooms, viz. Candida cretensis and Candida vadensis, and two from rotten wood, viz. Blastobotrys robertii and Candida scorzettiae. Accession numbers for the CBS and ARS Culture Collections, and GenBank accession numbers for the D1/D2 domains of the large subunit of ribosomal DNA are: B. robertii CBS 10106^T, NRRL Y-27775, DQ839395; C. cretensis CBS 9453^T, NRRL Y-27777, AY4998861 and DQ839393; C. scorzettiae CBS 10107^T, NRRL Y-27665, DQ839394; C. vadensis CBS 9454^T, NRRL Y-27778, AY498863 and DQ839396. The GenBank accession number for the ITS region of C. cretensis is AY498862 and that for C. vadensis is AY498864. C. cretensis was the only species of the four that displayed fermentative activity. All four type strains grew on n-hexadecane. C. scorzettiae is the only one of the new species that assimilates some phenolic compounds, viz. 3-hydroxy derivatives of benzoic, phenylacetic and cinnamic acids, but not the corresponding 4-hydroxy acids. This is indicative of an operative gentisate pathway.     

Candida alocasiicola sp. nov., Candida hainanensis sp. nov., Candida heveicola sp. nov. and Candida musiphila sp. nov., novel anamorphic, ascomycetous yeast species isolated from plants

In a taxonomic study on the ascomycetous yeasts isolated from plant materials collected in tropical forests in Yunnan and Hainan Provinces, southern China, four strains isolated from tree sap (YJ2E(T)) and flowers (YF9E(T), YWZH3C(T) and YYF2A(T)) were revealed to represent four undescribed yeast species. Molecular phylogenetic analysis based on the large subunit (26S) rRNA gene D1/D2 domain sequences showed that strain YJ2E(T) was located in a clade together with Candida haemulonii and C. pseudohaemulonii. Strain YF9E(T) was most closely related to C. azyma and strain YWZH3C(T) to C. sorbophila and C. spandovensis. Strain YYF2A(T) was clustered in a clade containing small-spored Metschnikowia species and related anamorphic Candida species. The new strains differed from their closely related described species by more than 10% mismatches in the D1/D2 domain. No sexual states were observed for the four strains on various sporulation media. The new species are therefore assigned to the genus Candida and described as Candida alocasiicola sp. nov. (type strain, YF9E(T) = AS 2.3484(T) = CBS 10702(T)), Candida hainanensis sp. nov. (type strain, YYF2A(T) = AS 2.3478(T) = CBS 10696(T)), Candida heveicola sp. nov. (type strain, YJ2E(T) = AS 2.3483(T) = CBS 10701(T)) and Candida musiphila sp. nov. (type strain, YWZH3C(T) = AS 2.3479(T) = CBS 10697(T)).     

Natronolimnobius baerhuensis gen. nov., sp. nov. and Natronolimnobius innermongolicus sp. nov., novel haloalkaliphilic archaea isolated from soda lakes in Inner Mongolia, China

Three novel isolates of haloalkaliphilic archaea, strains IHC-005^T, IHC-010, and N-1311^T, from soda lakes in Inner Mongolia, China, were characterized to elucidate their taxonomic positions. The three strains were aerobic, Gram-negative chemoorganotrophs growing optimally at 37–45°C, pH 9.0–9.5, and 15–20% NaCl. Cells of strains IHC-005^T/IHC-010 were motile rods, while those of strain N-1311^T were non-motile pleomorphic flats or cocci. The three strains contained diphytanyl and phytanyl-sesterterpanyl diether derivatives of phosphatidylglycerol and phosphatidylglycerophosphate methyl ester. No glycolipids were detected. On phylogenetic analysis of 16S rRNA gene sequences, they formed an independent cluster in the Natro group of the family Halobacteriaceae. Comparison of their morphological, physiological, and biochemical properties, DNA G+C content and 16S rRNA gene sequences, and DNA-DNA hybridization study support the view that strains IHC-005^T/IHC-010 and strain N-1311^T represent separate species. Therefore, we propose Natronolimnobius baerhuensis gen. nov., sp. nov. for strains IHC-005^T (=CGMCC 1.3597^T =JCM 12253^T)/IHC-010 (=CGMCC 1.3598=JCM 12254) and Natronolimnobius innermongolicus sp. nov. for N-1311^T (=CGMCC 1.2124^T =JCM 12255^T).     

Nonomuraea terrinata sp. nov., a novel soil actinomycete

The taxonomic position of a soil isolate, strain E626, was evaluated using the polyphasic approach. The organism was found to have chemical and morphological features consistent with its assignment to the genus Nonomuraea, a member of the family Streptosporangiaceae. Strain E626 consistently formed a distinct phyletic line within the Streptosporangiaceae 16S rDNA tree using four different algorithms. Furthermore, the taxonomic distinctness of the organism is underpinned by a range of phenotypic properties, notably morphological features. It is, therefore, proposed that the organism be classified in the genus Nonomuraea as Nonomuraea terrinata sp. nov. This revised version was published online in June 2006 with corrections to the Cover Date.     

Classification of novel soil streptomycetes as Streptomyces aureus sp. nov., Streptomyces laceyi sp. nov. and Streptomyces sanglieri sp. nov

The taxonomic positions of soil isolates known as Streptomyces groups A, B and C were clarified. Comparative 16S rDNA sequence studies indicated that representatives of all three taxa formed distinct phyletic lines within the Streptomyces tree though the group A strains were shown to be related to Streptomyces griseus and associated validly described species. The taxonomic integrity of all three groups was highlighted by DNA:DNA relatedness and ribotype data though the group A strains encompassed a higher degree of genetic variation than the group B and C strains. In light of these and earlier phenotypic data it is proposed that Streptomyces groups A, B and C be given species status as Streptomyces sanglieri sp. nov., Streptomyces aureus sp. nov. and Streptomyces laceyi sp. nov., respectively. This revised version was published online in June 2006 with corrections to the Cover Date.     

Anoxybacillus kamchatkensis sp. nov., a novel thermophilic facultative aerobic bacterium with a broad pH optimum from the Geyser valley, Kamchatka

A facultative aerobic, moderately thermophilic, spore forming bacterium, strain JW/VK-KG4 was isolated from an enrichment culture obtained from the Geyser valley, a geothermally heated environment located in the Kamchatka peninsula (Far East region of Russia). The cells were rod shaped, motile, peritrichous flagellated stained Gram positive and had a Gram positive type cell wall. Aerobically, the strain utilized a range of carbohydrates including glucose, fructose, trehalose, proteinuous substrates, and pectin as well. Anaerobically, only carbohydrates are utilized. When growing on carbohydrates, the strain required yeast extract and vitamin B₁₂. Anaerobically, glucose was fermented to lactate as main product and acetate, formate, ethanol as minor products. Aerobically, even in well-aerated cultures (agitated at 500 rpm), glucose oxidation was incomplete and lactate and acetate were found in culture supernatants as by-products. Optimal growth of the isolate was observed at pH^{25 C} 6.8–8.5 and 60°C. The doubling times on glucose at optimal growth conditions were 34 min (aerobically) and 40 min (anaerobically). The G+C content was 42.3 mol% as determined by T_m assay. Sequence analysis of the 16S rRNA gene indicated an affiliation of strain JW/VK-KG4 with Anoxybacillus species. Based on its morphology, physiology, phylogenetic relationship and its low DNA-DNA homology with validly published species of Anoxybacillus, it is proposed that strain JW/VK-KG4 represents a new species in the genus Anoxybacillus as A. kamchatkensis sp. nov. The type strain for the novel species is JW/VK-KG4^T (=DSM 14988, =ATCC BAA-549). The GenBank accession number for the 16S rDNA sequence is AF510985.     

Erythrobacter vulgaris sp. nov., a novel organism isolated from the marine invertebrates

Four yellow-pigmented, gram-negative, chemoorganotrophic aerobic bacteria were isolated from starfish Stellaster equestris (strains 022-2-10T, 022-2-9, and 022-2-12) and soft coral (unidentified species) (strain 022-4-7) collected in the South China Sea. 16S rRNA gene sequence-based analyses of the new organisms revealed that Erythrobacter spp. were the closest relatives and shared the highest similarity of 98.7% to E. citreus, 98.5% to E. flavus, 97.9% to E. litoralis and 97.6% to E. longus. The novel organisms were tolerant to 3-6% NaCl, grew between 10 degrees C and 40 degrees C, and were not able to degrade gelatin, casein, and agar, while degraded Tween 80. Two strains (022-2-9 and 022-2-12) could weakly degrade starch. All strains produced a large pool of carotenoids and did not have Bacteriochlorophyll a. Phosphatidylethanolamine (30-36%), phosphatidylglycerol (39-46%), and phosphatidylcholine (21-27%) were the predominant phospholipids. Sphingoglycolipid was not detected. The major fatty acids were 16:0 (6-11%), 16:1omega7 (12-15%), and 18:1omega7 (46-49%). The two-hydroxy fatty acids, 13:0-2OH, 14:0-2OH, 15:0-2OH, 16:0-2OH were also present. The G + C content of the DNAs ranged from 61 to 62 mol%. The level of DNA similarity among four strains was conspecific and ranged from 94% to 98%. Even though new strains and other species of the genus had rather high level of 16S rRNA gene sequence similarities, DNA-DNA hybridization experiments showed only 33-39% of binding with the DNA of the type strains. On the basis of these results and the significant differences demonstrated in the phenotypic and chemotaxonomic characteristics, it is suggested that the new organisms be classified as a novel species; the name Erythrobacter vulgaris sp. nov. is proposed. The type strain is 022-2-10T (= KMM 3465T = CIP 107841T).     

New anamorphic yeast species: Candida infanticola sp. nov., Candida polysorbophila sp. nov., Candida transvaalensis sp. nov. and Trigonopsis californica sp. nov

Three new species of Candida and a new species of Trigonopsis are described based on their recognition from phylogenetic analysis of gene sequences from large subunit ribosomal RNA, ITS1/ITS2 rRNA, mitochondrial small subunit rRNA and cytochrome oxidase II. Candida infanticola sp. nov. (type strain NRRL Y-17858, CBS 7922) was isolated from the ear of an infant in Germany and is closely related to Candida sorbophila. Candida polysorbophila sp. nov. (type strain NRRL Y-27161, CBS 7317) is a member of the Zygoascus clade and was isolated in South Africa as a contaminant from an emulsion of white oil and polysorbate. Candida transvaalensis sp. nov. (type strain NRRL Y-27140, CBS 6663) was obtained from forest litter, the Transvaal, South Africa, and forms an isolated clade with Candida santjacobensis. Trigonopsis californica sp. nov. (type strain NRRL Y-27307, CBS 10351) represents a contaminant from wine in California, and forms a well-supported clade with Trigonopsis cantarellii, Trigonopsis variabilis and Trigonopsis vinaria.     

Isolation and characterization of Dehalospirillum multivorans gen. nov., sp. nov., a tetrachloroethene-utilizing,strictly anaerobic bacterium

A strictly anaerobic bacterium dechlorinating tetrachloroethene (perchloroethylene, PCE) via trichloroethene (TCE) to cis-1,2-dichloroethene (DCE) was isolated from activated sludge with pyruvate plus PCE as energy substrates. The organism, called Dehalospirillum multivorans, is a gram-negative spirillum that does not form spores. The G+C content of the DNA was 41.5 mol%. According to 16S rRNA gene sequence analysis, D. multivorans represents a new genus and a new species belonging to the epsilon subdivision of Proteobacteria. Quinones, cytochromes b and c, and corrinoids were extracted from the cells. D. multivorans grew in defined medium with PCE and H₂ as sole energy sources and acetate as carbon source; the growth yield under these conditions was 1.4g of cell protein per mol chloride released. Alternatively to PCE, fumarate and nitrate could serve as electron acceptors; sulfate could not replace fumarate, nitrate, or PCE in this respect. In addition to H₂, the organism utilized a variety of electron donors for dechlorination (pyruvate, lactate, ethanol, formate, glycerol). Upon growth on pyruvate plus PCE, the main fermentation products formed were acetatc, lactate, DCE, and H₂. At optimal pH (7.3–7.6) and temperature (30°C), and in the presence of pyruvate (20mM) and PCE (160M), a dechlorination rate of about 50 nmol min^-1 (mg cell protein)^-1 and a doubling time of about 2.5h were obtained with growing cultures. The ability to reduce PCE to DCE appears to be constitutive under the experimental conditions applied since cultures growing in the absence of PCE for several generations immediately started dechlorination when transferred to a medium containing PCE. The organism may be useful for bioremediation of environments polluted with tetrachloroethene.Abbreviations PCE Perchloroethylene, tetrachloroethene - TCE Trichloroethene - DCE cis-1,2-Dichloroethene - CHC Chlorinated hydrocarbon     

Gordonia sinesedis sp. nov., a novel soil isolate

The taxonomic position of an actinomycete isolated from soil was evaluated using a polyphasic approach. The organism, strain J72, was found to have chemical and morphological properties consistent with its assignment to the genus Gordonia. A nearly complete 16S rDNA sequence of the strain was determined by direct sequencing of the amplified gene. The tested strain formed a distinct phylogenetic line within the evolutionary radiation occupied by the genus Gordonia and was most closely related to G. polyisoprenivorans DSM 44302^T. The phenotypic profile of strain 372 readily distinguishes it from representatives of the validly described species of Gordonia. The combined genotypic and phenotypic data show that strain J72 merits recognition as a new species of Gordonia. The name proposed for the new species is Gordonia sinesedis; the type strain is J72^T (= DSM 44455^T = NCIMB 13802^T). This revised version was published online in June 2006 with corrections to the Cover Date.