Gracilimonas amylolytica sp. nov., isolated from deep-sea sediment.

A Gram-stain-negative, aerobic, non-motile and rod-shaped bacterium, designated LA399T, was isolated from deep-sea sediment collected from the Pacific Ocean. Cells of strain LA399T grew in the medium containing 0-10.0 % of NaCl (w/v; optimum 3.0-5.0 %), pH 6.5-8.0 (optimum 7.0) and 20-40 °C (optimum 37 °C). Aesculin, gelatin, starch and Tween 80 were hydrolysed. Strain LA399T was closely related to Gracilimonas halophila WDS2C40T (97.0 % sequence similarity), Gracilimonas mengyeensis YIM J14T (96.4 %), Gracilimonas rosea CL-KR2T (96.4 %) and Gracilimonas tropica DSM 19535T (96.0 %), and exhibited equal or less than 96.0 % sequence similarity to other type strains of species with validly published names. Phylogenetic analyses revealed that strain LA399T clustered with the clade comprising the Gracilimonas species and formed an independent lineage. Strain LA399T contained menaquinone 7 as the sole isoprenoid quinone and iso-C15 : 0, anteiso-C15 : 0, summed feature 3 (C16 : 1ω7c/C16 : 1ω6c) and summed feature 9 (iso-C17 : 1ω9c/10-methyl C16 : 0) as the predominant cellular fatty acids. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid and three unidentified glycolipids. The DNA G+C content was 45.3 mol%. According to the phylogenetic, chemotaxonomic and phenotypic data, it represents a novel species of the genus Gracilimonas, for which the name Gracilimonas amylolytica is proposed. The type strain is LA399T (=CGMCC 1.16248T=KCTC 52885T).

Rhodohalobacter barkolensis sp. nov., isolated from a saline lake and emended description of the genus Rhodohalobacter.

A Gram-stain-negative, non-motile, aerobic, rod-shaped bacterium, designated 15182T, was isolated from a saline lake in China. The novel strain 15182T was able to grow at 10-40 °C (optimum, 37 °C), pH 7.0-8.0 (optimum, 7.5) and with 0.5-4 % NaCl (optimum, 2-3 %, w/v). The phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 15182T was most closely related to the genus Rhodohalobacter by sharing the highest sequence similarity of 97.0 % with Rhodohalobacter halophilus JZ3C29T. Chemotaxonomic analysis showed that the sole respiratory quinone was menaquinone 7, the major fatty acids included C16 : 0 N alcohol and C16 : 1ω11c. The major polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, four uncharacterized glycolipids, one uncharacterized phospholipid and two uncharacterized lipids. The genomic DNA G+C content of the strain 15182T was 42.4 mol%. The average nucleotide identity value between 15182T and R. halophilus JZ3C29T was 75.4 %, and the in silico DNA-DNA hybridization value of the two strains was 19.1 %. On the basis of its phenotypic, chemotaxonomic, genotypic and genomic characteristics presented in this study, strain 15182T is suggested to represent a novel species in the genus Rhodohalobacter, for which the name Rhodohalobacter barkolensis sp. nov. is proposed. The type strain is 15182T (=KCTC 62172T=MCCC 1K03442T). An emended description of the genus Rhodohalobacter is also presented.

Meiothermus luteus sp. nov., a slightly thermophilic bacterium isolated from a hot spring.

A slightly thermophilic, aerobic bacterium, designated YIM 72257T, was isolated from a sediment sample taken from a hot spring in Tengchong county, Yunnan province, south-west China. The isolate was Gram-stain-negative, non-sporulating and forms non-motile rods, appearing in chains. The isolate grew at 50-65 °C, pH 6.0-9.0 and with 0.5-1 % NaCl (w/v). 16S rRNA gene sequence analysis showed that strain YIM 72257T was most closely related to Meiothermus cateniformans LY1T (95.6 %), Meiothermus ruber DSM 1279T (95.1 %) and Meiothermus taiwanensis WR-30T (94.6 %). The genomic DNA G+C content of strain YIM 72257T was 62.6 mol%. The main cellular fatty acids (>5 %) were anteiso-C15 : 0, anteiso-C17 : 0, iso-C16 : 0, iso-C17 : 0, iso-C15 : 0 and C16 : 0. The polar lipids consisted of an uncharacterized phospholipid and two glycolipids. Based on phenotypic, phylogenetic and chemotaxonomic characteristics, strain YIM 72257T is proposed to be a representative of a novel species of the genus Meiothermus, for which the name Meiothermus luteus sp. nov. is proposed. The type strain is YIM 72257T (=KCTC 52599T=CCTCC AB 2017100T).

Longimicrobium terrae gen. nov., sp. nov., an oligotrophic bacterium of the under-represented phylum Gemmatimonadetes isolated through a system of miniaturized diffusion chambers.

A novel chemo-organoheterotroph bacterium, strain CB-286315T, was isolated from a Mediterranean forest soil sampled at the Sierra de Tejeda, Almijara and Alhama Natural Park, Spain, by using the diffusion sandwich system, a device with 384 miniature diffusion chambers. 16S rRNA gene sequence analyses identified the isolate as a member of the under-represented phylum Gemmatimonadetes, where 'Gemmatirosa kalamazoonensis' KBS708, Gemmatimonas aurantiaca T-27T and Gemmatimonas phototrophica AP64T were the closest relatives, with respective similarities of 84.4, 83.6 and 83.3 %. Strain CB-286315T was characterized as a Gram-negative, non-motile, short to long rod-shaped bacterium. Occasionally, some cells attained an unusual length, up to 35-40 µm. The strain showed positive responses for catalase and cytochrome-c oxidase and division by binary fission, and exhibited an aerobic metabolism, showing optimal growth under normal atmospheric conditions. Strain CB-286315T was also able to grow under micro-oxic atmospheres, but not under anoxic conditions. The strain is a slowly growing bacterium able to grow under low nutrient concentrations. Major fatty acids included iso-C17 : 1ω9c, summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), C16 : 0 and iso-C17 : 0. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, two unidentified glycolipids and three phospholipids. The major isoprenoid quinone was MK-8 and the diagnostic diamino acid was meso-diaminopimelic acid. The DNA G+C content was 67.0 mol%. Based on a polyphasic taxonomic characterization, strain CB-286315T represents a novel genus and species, Longimicrobium terrae gen. nov., sp. nov., within the phylum Gemmatimonadetes. The type strain of Longimicrobium terrae is strain CB-286315T ( = DSM 29007T = CECT 8660T). In order to classify the novel taxon within the existing taxonomic framework, the family Longimicrobiaceae fam. nov., order Longimicrobiales ord. nov. and class Longimicrobia classis nov. are also proposed.

Characterization of the biochemical properties of recombinant Xyn10C from a marine bacterium, Saccharophagus degradans 2-40.

Endo-1,4-ß-xylanases are mostly classified into glycoside hydrolase (GH) family 10 or 11. In this study, we examined the catalytic functions of a recombinant endo-1,4-ß-xylanase belonging to GH10 (Xyn10C) from a marine bacterium, Saccharophagus degradans 2-40. Optimal activity of this enzyme was evident at 30 °C and pH 7.0, but activity remained even at low temperatures, indicating its adaptation to cold. With respect to other xylanases known to be active in cold temperatures, Xyn10C is unique in that it showed maximal activity in the presence of 2 M of NaCl. The action patterns of recombinant Xyn10C on xylans from hardwood and softwood differed in part, but the enzyme hydrolyzed polysaccharidic substrates primarily to xylobiose and xylotriose through xylo-oligosaccharides, releasing a small amount of xylose. The K m and V max values on birchwood xylan were 10.4 mg mL(-1) and 253 µmol mg(-1) min(-1), respectively. The efficient catalytic function of Xyn10C on short-length xylo-oligosaccharide chains was similar to the typical function of other known GH10 xylanases.

Lentisphaera profundi sp. nov., isolated from deep-sea water.

A Gram-staining-negative, aerobic, non-motile, coccus-shaped bacterium, designated SAORIC-696T, was isolated from deep-sea water at a depth of 1700 m in the western North Pacific Ocean. Optimal growth of strain SAORIC-696T was observed at 15 °C, pH 7.0 and in the presence of 2 % (w/v) NaCl. Strain SAORIC-696T formed a robust phylogenetic clade with members of the genus Lentisphaera. The 16S rRNA gene sequence similarity showed that strain SAORIC-696T was most closely related to Lentisphaera marina (98.0 % similarity) and Lentisphaera araneosa (97.3 %). The DNA-DNA relatedness between SAORIC-696T and two species of the genus Lentisphaera was only 27-42 %. The DNA G+C content of strain SAORIC-696T was 43.1 mol% and predominant cellular fatty acids were C16 : 1ω9c (36.8 %), C14 : 0 (22.5 %) and C14 : 0 3-OH and/or iso-C16 : 1 I (10.8 %). Strain SAORIC-696T contained MK-7 as the only respiratory quinone. On the basis of taxonomic data collected in this study, it was concluded that strain SAORIC-696T represents a novel species of the genus Lentisphaera, for which the name Lentisphaera profundi sp. nov. is proposed, with the type strain SAORIC-696T ( = NBRC 110692T = KCTC 42681T).

Characteristics of hydrocarbon hydroxylase genes in a thermophilic aerobic biological system treating oily produced wastewater.

Alkane and aromatic hydroxylase genes in a full-scale aerobic system treating oily produced wastewater under thermophilic condition (45-50 °C) in the Jidong oilfield, China, were investigated using clone library and quantitative polymerase chain reaction methods. Rather than the normally encountered integral-membrane non-haem iron monooxygenase (alkB) genes, only CYP153-type P450 hydroxylase genes were detected for the alkane activation, indicating that the terminal oxidation of alkanes might be mainly mediated by the CYP153-type alkane hydroxylases in the thermophilic aerobic process. Most of the obtained CYP153 gene clones showed distant homology with the reference sequences, which might represent novel alkane hydroxylases. For the aromatic activation, the polycyclic aromatic hydrocarbon-ring hydroxylating dioxygenase (PAH-RHD) gene was derived from Gram-negative PAH-degraders belonging to the Burkholderiales order, with a 0.72% relative abundance of PAH-RHD gene to 16S rRNA gene. This was consistent with the result of 16S rRNA gene analysis, indicating that Burkholderiales bacteria might play a key role in the full-scale process of thermophilic hydrocarbon degradation.

Crenobacter luteus gen. nov., sp. nov., isolated from a hot spring.

A slightly thermophilic, Gram-staining-negative and strictly aerobic bacteria, designated strain YIM 78141(T), was isolated from a sediment sample collected at Hehua hot spring, Tengchong, Yunnan province, south-west China. Cells of the strain were short-rod-shaped and colonies were yellowish and circular. The strain grew at pH 6.0-10.0 (optimum, pH 8.0-9.0) and 10-55 °C (optimum, 40-50 °C). Phylogenetic analyses based on 16S rRNA gene sequence comparison demonstrated that strain YIM 78141(T) belongs to the family Neisseriaceae, and strain YIM 78141(T) also showed low levels of 16S rRNA gene sequence similarity (below 93.4%) with all other genera in this family. The only quinone was ubiquinone 8 and the genomic DNA G+C content was 67.3 mol%. Major fatty acids (>5%) were C12:0, C16:0, C18:1ω7c and summed feature 3. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phospholipids of unknown structure containing aminoglycophospholipid and three unidentified polar lipids. On the basis of the morphological, physiological and biochemical characteristics as well as genotypic data, this strain should be classified as a representative of a novel genus and species of the family Neisseriaceae, for which the name Crenobacter luteus gen. nov., sp. nov. is proposed. The type strain is YIM 78141(T) ( =BCRC 80650(T) =KCTC 32558(T) =DSM 27258(T)).

Variibacter gotjawalensis gen. nov., sp. nov., isolated from soil of a lava forest.

A novel bacterial strain designated GJW-30(T) was isolated from soil of the lava forest, Gotjawal, located in Aewol, Jeju, Korea. Strain GJW-30(T) was found to be strictly aerobic, Gram-negative and to form pleomorphic, non-motile rods and white colonies on R2A agar. The major fatty acids were identified as C18:1ω7c, C16:0 and C17:0, the predominant isoprenoid quinone as Q-10, the polar lipids as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unidentified aminolipid and an unidentified lipid. The cell-wall sugar pattern of strain GJW-30(T) was found to be composed of glucose, ribose and rhamnose and meso-DAP as the diagnostic diamino acid in the cell-wall peptidoglycan. The DNA G+C content of strain GJW-30(T) is 62.2 mol%. Phylogenetic analysis, based on 16S rRNA gene sequence similarities, showed that strain GJW-30(T) forms a deep branch within the order Rhizobiales, sharing the highest level of sequence homology with Bradyrhizobium oligotrophicum LMG 10732(T) (93.6 %). On the basis of the phenotypic, chemotaxonomic and phylogenetic characteristics, strain GJW-30(T) is considered to represent a novel genus and species, for which the name Variibacter gotjawalensis gen. nov., sp. nov. (the type strain is GJW-30(T) = KCTC 32391(T) = CECT 8514(T) = LMG 28093(T)) is proposed.

Meiothermus terrae sp. nov., isolated from a geothermally heated soil sample.

A Gram-negative, aerobic bacterium, designated strain YIM 77755(T), was isolated from a geothermally heated soil sample collected at Rehai National Park, Tengchong, Yunnan province, south-west China. Cells of the strain were rod-shaped and colonies were yellow and circular. Growth occurred in 0-1 % (w/v) NaCl, at pH 6.0-8.0 (optimum, pH 7.0) and at 35-55 °C (optimum, 50 °C). The predominant menaquinone was MK-8 and the DNA G+C content was 68.9 mol%. Major fatty acids (>10 %) were anteiso-C15 : 0 and iso-C15 : 0. The polar lipids consisted of an uncharacterized phospholipid and four glycolipids. Based on 16S rRNA gene sequence analysis, strain YIM 77755(T) formed a cluster with Meiothermus chliarophilus ALT-8(T) and showed the highest 16S rRNA gene sequence similarity to M. chliarophilus ALT-8(T) (98.23 %). DNA-DNA relatedness between YIM 77755(T) and M. chliarophilus DSM 9957(T) was 54.9±4.1 %. On the basis of the morphological and chemotaxonomic characteristics as well as genotypic data, it is proposed that strain YIM 77755(T) represents a novel species of the genus Meiothermus, named Meiothermus terrae sp. nov. The type strain is YIM 77755(T) ( = DSM 26712(T) = CCTCC AB 2012942(T)).

Usefulness of PCR-HRMA in identification of non-fermentative Gram-negative rods recovered from patients suffering from cystic fibrosis or chronic obstructive pulmonary disease.

Adequate treatment of microbial infections requires rapid and accurate identification of the etiological agent. In routine diagnostics, identification of bacteria conventionally relies on phenotypic testing, which can be hindered by phenotypic variations. Therefore, genotyping techniques should perform faster and more accurately. Recently, the technique of high-resolution melting analysis (HRMA) of PCR amplicons promises to provide a convenient and economic tool of genotypic identification. In our study, we performed prospective routine testing of a PCR-HRMA system that was recently published in a proof-of-the-principle study. The system was evaluated by analysing 275 clinical isolates of bacteria acquired from 65 patients suffering from cystic fibrosis or chronic obstructive pulmonary disease. Our results show that its routine use may result in partial worsening of its discriminatory power; however, it still outmatched conventional phenotyping in the group of non-fermentative Gram-negative rods. Moreover, when supplemented by rapid, simple and economic oxidase test, it can be even simplified for more economic performance.

Shifts in the microbial community composition of Gulf Coast beaches following beach oiling.

Microorganisms associated with coastal sands serve as a natural biofilter, providing essential nutrient recycling in nearshore environments and acting to maintain coastal ecosystem health. Anthropogenic stressors often impact these ecosystems, but little is known about whether these disturbances can be identified through microbial community change. The blowout of the Macondo Prospect reservoir on April 20, 2010, which released oil hydrocarbons into the Gulf of Mexico, presented an opportunity to examine whether microbial community composition might provide a sensitive measure of ecosystem disturbance. Samples were collected on four occasions, beginning in mid-June, during initial beach oiling, until mid-November from surface sand and surf zone waters at seven beaches stretching from Bay St. Louis, MS to St. George Island, FL USA. Oil hydrocarbon measurements and NOAA shoreline assessments indicated little to no impact on the two most eastern beaches (controls). Sequence comparisons of bacterial ribosomal RNA gene hypervariable regions isolated from beach sands located to the east and west of Mobile Bay in Alabama demonstrated that regional drivers account for markedly different bacterial communities. Individual beaches had unique community signatures that persisted over time and exhibited spatial relationships, where community similarity decreased as horizontal distance between samples increased from one to hundreds of meters. In contrast, sequence analyses detected larger temporal and less spatial variation among the water samples. Superimposed upon these beach community distance and time relationships, was increased variability in bacterial community composition from oil hydrocarbon contaminated sands. The increased variability was observed among the core, resident, and transient community members, indicating the occurrence of community-wide impacts rather than solely an overprinting of oil hydrocarbon-degrading bacteria onto otherwise relatively stable sand population structures. Among sequences classified to genus, Alcanivorax, Alteromonas, Marinobacter, Winogradskyella, and Zeaxanthinibacter exhibited the largest relative abundance increases in oiled sands.

Falsochrobactrum ovis gen. nov., sp. nov., isolated from a sheep.

A Gram-stain-negative, rod-shaped, oxidase-positive, non-spore-forming, non-motile bacterium (B1315(T)) was isolated from the placenta of a sheep with abortion. On the basis of 16S rRNA gene sequence analyses the strain was assigned to the Brucella-Ochrobactrum-Paenochrobactrum-Pseudochrobactrum group with 94.5-94.8 %, 94.3-96.1 %, 95.0-95.1 %, and 95.9-96.1 % sequence similarities to type strains of species of the four genera, respectively. Phylogenetic trees indicated a close relationship to the type strains of Ochrobactrum gallinifaecis and Ochrobactrum oryzae (95.9 and 96.1 % sequence similarity, respectively). Chemotaxonomic data confirmed the allocation of strain B1315(T) to the family Brucellaceae (quinone system: ubiquinone Q-10 and major fatty acids: C18 : 1ω7c and C19 : 0 cyclo ω8c). The polar lipid profile contained the major lipids diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and the unidentified but unique phospholipid PL7. The polyamine pattern of strain B1315(T) contained the major polyamines spermidine and putrescine. On the basis of the 16S rRNA gene and recA sequence phylogeny and chemotaxonomic data strain B1315(T) was clearly different from the genera Brucella, Ochrobactrum, Paenochrobactrum and Pseudochrobactrum. On the basis of these data we propose the novel genus Falsochrobactrum gen. nov. with the type species Falsochrobactrum ovis sp. nov. with the type strain B1315(T) ( = CCM 8460(T) = LMG 27356(T.)) The taxonomic allocation of O. gallinifaecis, which grouped inconsistently together with strain B1315(T) on the basis of 16S rRNA gene sequence data, but shows the chemotaxonomic features of the genus Ochrobactrum, remains to be clarified.

Analysis of the intraimplant microflora of two-piece dental implants.

OBJECTIVE: Information about the spectrum of microorganisms in the intraimplant cavities of two-piece dental implants is scarce. The purpose of this study was to assess the intraimplant microflora of two-piece dental implants by conventional biochemical testing, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and 16 s rDNA gene sequencing. MATERIALS AND METHODS: Ten patients (six men and four women; average age = 66.7 years; age range = 58-78 years) received 35 two-piece titanium implants carrying ball attachments. Biofilm sampling was performed with sterile microbrushes, and nonadherent microbial samples were obtained by injection and reuptake of predefined volumes of NaCl solution. The samples were cultured and analyzed by conventional biochemical testing, MALDI-TOF MS, and 16 s rDNA gene sequencing. RESULTS: Of the 103 species detected, 27 and 33 were identified only in the biofilm and nonadherent microbial samples, respectively. Forty-three species were identified in both types of samples. CONCLUSIONS: Two-piece dental implants harbored a broad spectrum of gram-positive and gram-negative aerobes and anaerobes, especially rods and cocci. CLINICAL RELEVANCE: These findings confirm bacterial translocation from the oral cavity to intraimplant cavities. Microbiological methods as used in this study are necessary to reveal the complete vital microflora of intraimplant cavities.

Mariniradius saccharolyticus gen. nov., sp. nov., a member of the family Cyclobacteriaceae isolated from marine aquaculture pond water, and emended descriptions of the genus Aquiflexum and Aquiflexum balticum.

A novel marine, Gram-stain-negative, oxidase- and catalase- positive, rod-shaped bacterium, designated strain AK6(T), was isolated from marine aquaculture pond water collected in Andhra Pradesh, India. The fatty acids were dominated by iso-C15:0, iso-C17:1ω9c, iso-C15:1 G, iso-C17:0 3-OH and anteiso-C15:0. Strain AK6(T) contained MK-7 as the sole respiratory quinone and phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified phospholipid and seven unidentified lipids as polar lipids. The DNA G+C content of strain AK6(T) was 45.6 mol%. Phylogenetic analysis showed that strain AK6(T) formed a distinct branch within the family Cyclobacteriaceae and clustered with Aquiflexum balticum DSM 16537(T) and other members of the family Cyclobacteriaceae. 16S rRNA gene sequence analysis confirmed that Aquiflexum balticum DSM 16537(T) was the nearest neighbour, with pairwise sequence similarity of 90.1%, while sequence similarity with the other members of the family was <88.5%. Based on differentiating phenotypic characteristics and phylogenetic inference, strain AK6(T) is proposed as a representative of a new genus and species of the family Cyclobacteriaceae, as Mariniradius saccharolyticus gen. nov., sp. nov. The type strain of Mariniradius saccharolyticus is AK6(T) (=MTCC 11279(T)=JCM 17389(T)). Emended descriptions of the genus Aquiflexum and Aquiflexum balticum are also proposed.

Comparison of two suspension arrays for simultaneous detection of five biothreat bacterial in powder samples.

We have developed novel Bio-Plex assays for simultaneous detection of Bacillus anthracis, Yersinia pestis, Brucella spp., Francisella tularensis, and Burkholderia pseudomallei. Universal primers were used to amplify highly conserved region located within the 16S rRNA amplicon, followed by hybridized to pathogen-specific probes for identification of these five organisms. The other assay is based on multiplex PCR to simultaneously amplify five species-specific pathogen identification-targeted regions unique to individual pathogen. Both of the two arrays are validated to be flexible and sensitive for simultaneous detection of bioterrorism bacteria. However, universal primer PCR-based array could not identify Bacillus anthracis, Yersinia pestis, and Brucella spp. at the species level because of the high conservation of 16S rDNA of the same genus. The two suspension arrays can be utilized to detect Bacillus anthracis sterne spore and Yersinia pestis EV76 from mimic "write powder" samples, they also proved that the suspension array system will be valuable tools for diagnosis of bacterial biothreat agents in environmental samples.

Insights into structure and function of the active site of SoxAX cytochromes.

SoxAX cytochromes catalyze the formation of heterodisulfide bonds between inorganic sulfur compounds and a carrier protein, SoxYZ. They contain unusual His/Cys-ligated heme groups with complex spectroscopic signatures. The heme-ligating cysteine has been implicated in SoxAX catalysis, but neither the SoxAX spectroscopic properties nor its catalysis are fully understood at present. We have solved the first crystal structure for a group 2 SoxAX protein (SnSoxAX), where an N-terminal extension of SoxX forms a novel structure that supports dimer formation. Crystal structures of SoxAX with a heme ligand substitution (C236M) uncovered an inherent flexibility of this SoxA heme site, with both bonding distances and relative ligand orientation differing between asymmetric units and the new residue, Met(236), representing an unusual rotamer of methionine. The flexibility of the SnSoxAX(C236M) SoxA heme environment is probably the cause of the four distinct, new EPR signals, including a high spin ferric heme form, that were observed for the enzyme. Despite the removal of the catalytically active cysteine heme ligand and drastic changes in the redox potential of the SoxA heme (WT, -479 mV; C236M, +85 mV), the substituted enzyme was catalytically active in glutathione-based assays although with reduced turnover numbers (WT, 3.7 s(-1); C236M, 2.0 s(-1)). SnSoxAX(C236M) was also active in assays using SoxYZ and thiosulfate as the sulfur substrate, suggesting that Cys(236) aids catalysis but is not crucial for it. The SoxYZ-based SoxAX assay is the first assay for an isolated component of the Sox multienzyme system.

Usefulness of the hsp60 gene for the identification and classification of Gram-negative anaerobic rods.

The hsp60 gene sequences were determined for 121 strains of Gram-negative anaerobic rods, including the genera Bacteroides, Barnesiella, Butyricimonas, Odoribacter, Parabacteroides, Paraprevotella, Porphyromonas, Prevotella and Tannerella. The mean pairwise hsp60 gene sequence similarity (73.8-97.1 %) between species in each genus, except for the genus Tannerella that comprises one species, was significantly less than that of the 16S rRNA gene sequence (88.3-96.3 %). Only pairwise hsp60 gene sequence similarity (97.1 %) of the genus Paraprevotella was higher than that of the 16S rRNA gene sequence (93.8 %). Each genus formed a distinct clade in the phylogenetic analysis of the hsp60 gene sequence as well as the 16S rRNA gene sequence. The phylogenetic analysis indicated a higher evolutionary rate for the hsp60 gene sequence than the 16S rRNA gene sequence, especially in the genera Porphyromonas and Prevotella. This study suggests that the hsp60 gene is a useful alternative phylogenetic marker for the identification and classification of a broad range of Gram-negative anaerobic rods.

Meiothermus granaticius sp. nov., a new slightly thermophilic red-pigmented species from the Azores.

Two red-pigmented isolates, with optimum growth temperatures between 45 and 50 degrees C, were recovered from a hot spring in the Furnas, Area da Fonte 1825 on the Island of São Miguel in the Azores. Phylogenetic analysis of the 16S rRNA gene sequences showed that these organisms represented a new species of the genus Meiothermus. These new isolates could be distinguished from other strains of the species of the genus Meiothermus primarily by the fatty acid composition and polar lipid pattern, since they did not possess 2-OH fatty acids or glycolipid variant GL-1a. Moreover, the two new isolates had the lowest growth temperature range of any of the known species of the genus Meiothermus. On the basis of the results presented here we propose the name Meiothermus granaticius for the new species represented by strains AF-68(T) (=DSM 23260(T)=LMG 25524(T)) and AF-49 (=DSM 23259=LMG 25525).

Quantitative PCR of pmoA using a novel reverse primer correlates with potential methane oxidation in Finnish fen.

We report a new reverse primer (A621r) for use with A189f in PCR amplification of pmoA alleles in type II methanotrophs. The new primer combination was used to successfully amplify pmoA in peat monolith samples of various depths taken from fen-type peatlands in Finland. In quantitative PCR, pmoA amplicons produced from two sets of three replicate monoliths showed a significant Pearson correlation coefficient (r=0.77 and 0.61) with methane oxidation potential. The maximum methane oxidation potential and number of pmoA amplicons ranged between 8.8-40.5 micromol g (dry weight)(-1) d(-1) and 5.5 x 10(7)-18.7 x 10(7) g (wet weight)(-1), respectively, occurring in depths between 10 and 30 cm beneath the surface in the seven individual monoliths used in this study.