Emticicia fluvialis sp. nov., a potential hormone-degrading bacterium isolated from Nakdong River, Republic of Korea

A novel species of the genus Emticicia, designated BHSR1T, was isolated from a water sample that was collected from the Nakdong River, Republic of Korea, and its taxonomic affiliation was studied using a polyphasic approach. This bacterium was Gram-stain-negative, non-motile, aerobic, curved, rod-shaped, and oxidase- and catalase-negative. The bacterium grew optimally at 37 °C, pH 7.5 and 0% (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain BHSR1T should be affiliated with the genus Emticicia, with a high similarity to Emticicia fontis KCTC 52248T (98.10%). Phylogenomic analysis also suggested that the strain represents a novel species in the genus Emticicia. The genomic G + C content was 41.9%. The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization between strain BHSR1T and its closely related relatives in the genus Emticicia were in ranges of 71.1-75.8%, 69.4-77.5% and 18.6-19.9%, respectively. The gene cluster within BHSR1T contained genes encoding enzymes that could be involved in hormone degradation. The major cellular fatty acids (> 10%) were summed feature 3 (comprising C16:1ω6c and/or C16:1ω7c) and iso-C15:0. With regards to the polar lipid profile, phosphatidylethanolamine (PE), two unidentified aminolipids and three unidentified lipids were identified as the major compounds. The major respiratory quinone was menaquinone (MK)-7. Based on its phylogenetic, phenotypic, chemotaxonomic, and genomic features, strain BHSR1T should be considered a novel species in the genus Emticicia of the family Spirosomaceae, for which the name Emticicia fluvialis sp. nov. is proposed. The type strain was considered BHSR1T (= KCTC 92622T = GDMCC 1.3740T).

Comparative study on the bacterial diversity and antibiotic resistance genes of urban landscape waters replenished by reclaimed water and surface water in Xi'an, China

Pathogenic bacteria and antibiotic resistance genes (ARGs) in urban landscape waters may pose a potential threat to human health. However, the investigation of their occurrence in the urban landscape waters replenished by reclaimed water (RW) and surface water (SW) is still insufficient. The water samples collected from six urban landscape waters replenished by RW or SW were used to analyze bacterial diversity using high-throughput sequencing of 16S rRNA gene and to detect 18 ARGs and 2 integron-integrase genes by means of quantitative PCR array. Results indicated that Proteobacteria was the dominant phylum in all six urban landscape waters. The bacterial species richness was lower in urban landscape waters replenished by RW than that by SW. Sulfonamide resistance genes (sulI and sulIII) were the major ARGs in these urban landscape waters. No significant difference in the relative abundance of sulfonamide resistance genes, tetracycline resistance genes, and most of beta-lactam resistance genes was observed between RW-replenished and SW-replenished urban landscape waters. By contrast, the relative abundance of bla_ampC gene and qnrA gene in RW-replenished urban landscape waters was significantly higher than that in SW-replenished urban landscape waters (p < 0.05), which suggested that use of RW may increase the amount of specific ARGs to urban landscape waters. Interestingly, among six urban landscape waters, RW-replenished urban landscape waters had a relatively rich variety of ARGs (12-15 of 18 ARGs) but a low relative abundance of ARGs (458.90-1944.67 copies/16S × 10⁶). The RW replenishment was found to have a certain impact on the bacterial diversity and prevalence of ARGs in urban landscape waters, which provide new insight into the effect of RW replenishment on urban landscape waters.

Emticicia agri sp. nov., a novel member of the family Cytophagaceae

A bacterial strain, 17J42-9^T, was isolated from a soil sample collected on Jeju Island, Republic of Korea. Cells were observed to be Gram-stain negative and rod-shaped. Colonies were observed to be orange in colour on R2A agar. Analysis of 16S rRNA gene sequences showed that high levels of 16S rRNA sequence similarity were shared between 17J42-9^T and Emticicia fontis IMCC1731^T (98.2 %), Emticicia ginsengisoliGsoil 085^T (98.2 %) and Emticicia soli ZZ-4^T (97.8 %). Growth of strain 17J42-9^T was observed at 10-37 °C, pH 6.0-8.5 and in the presence of 0-0.5 % NaCl. The genomic G+C content was calculated to be 38.6 mol%. The predominant respiratory quinone of the isolate was found to be MK-7; the major fatty acids were identified as summed feature 3 (C_16 : 1 ω7c and/or C_16 : 1 ω6c) (34.1 %), C_15 : 0iso (23.4 %) and C_17 : 0iso 3-OH (10.8 %). The major polar lipids were found to be phosphatidylethanolamine, two unidentified aminolipids and an unidentified lipid. The phenotypic and chemotaxonomic data support the affiliation of strain 17J42-9^T with the genus Emticicia. However, the DNA-DNA relatedness between the isolate and its closest phylogenetic neighbours was lower than 46 %. The results of 16S rRNA gene sequence similarity analysis, DNA-DNA hybridization analysis and the observed differentiating phenotypic properties from other closely related taxa clearly indicate that strain 17J42-9^T represents a novel species in the genus Emticicia, for which the name Emticiciaagri sp. nov. is proposed. The type strain is 17J42-9^T (=KCTC 62270^T=JCM 33056^T).

Enhanced production of biomass and lipids by Euglena gracilis via co-culturing with a microalga growth-promoting bacterium, Emticicia sp. EG3

BACKGROUND

Euglena gracilis, a unicellular flagellated microalga, is regarded as one of the most promising species as microalgal feedstock for biofuels. Its lipids (mainly wax esters) are suitable for biodiesel and jet fuel. Culture of E. gracilis using wastewater effluent will improve the economics of E. gracilis biofuel production. Enhancement of the productivity of E. gracilis biomass is critical to creating a highly efficient biofuels production system. Certain bacteria have been found to promote microalgal growth by creating a favorable microenvironment. These bacteria have been characterized as microalgae growth-promoting bacteria (MGPB). Co-culture of microalgae with MGPB might offer an effective strategy to enhance microalgal biomass production in wastewater effluent culture systems. However, no MGPB has been identified to enhance the growth of E. gracilis. The objectives of this study were, therefore, to isolate and characterize the MGPB effective for E. gracilis and to demonstrate that the isolated MGPB indeed enhances the production of biomass and lipids by E. gracilis in wastewater effluent culture system.

RESULTS

A bacterium, Emticicia sp. EG3, which is capable of promoting the growth of microalga E. gracilis, was isolated from an E. gracilis-municipal wastewater effluent culture. Biomass production rate of E. gracilis was enhanced 3.5-fold and 3.1-fold by EG3 in the co-culture system using a medium of heat-sterilized and non-sterilized wastewater effluent, respectively, compared to growth in the same effluent culture but without EG3. Two-step culture system was examined as follows: E. gracilis was cultured with or without EG3 in wastewater effluent in the first step and was further grown in wastewater effluent in the second step. Production yields of biomass and lipids by E. gracilis were enhanced 3.2-fold and 2.9-fold, respectively, in the second step of the system in which E. gracilis was co-cultured with EG3 in the first step.

CONCLUSION

Emticicia sp. EG3 is the first MGPB for E. gracilis. Growth-promoting bacteria such as EG3 will be promising agents for enhancing E. gracilis biomass/biofuel productivities.

Larkinella terrae sp. nov., isolated from soil on Jeju Island, South Korea

A Gram-stain negative, non-motile, rod-shaped, aerobic bacterium, designated 15J8-8^T, was isolated from a soil sample collected on Jeju Island, South Korea, and characterized taxonomically using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain 15J8-8^T belongs to the family Cytophagaceae and is related to Larkinella bovis M2TB15^T (95.0%), 'Larkinella harenae' 15J9-9 (94.5%), Larkinella arboricola Z0532^T (93.2%), and Larkinella insperata LMG 22510^T (93.0%). The DNA G+C content of strain 15J8-8^T was 50.5 mol%. The detection of phosphatidylethanolamine and two unidentified polar lipids as major polar lipids; menaquinone-7 as the predominant quinone; and C_16:1 ω5c, C_16:0 N alcohol, and iso-C_15:0 as the major fatty acids also supported the affiliation of the isolate to the genus Larkinella. Based on its phenotypic properties and phylogenetic distinctiveness, strain 15J8-8^T should be classified in the genus Larkinella as representative of a novel species, for which the name Larkinella terrae sp. nov. is proposed. The type strain is 15J8-8^T (= KCTC 52001^T = JCM 31990^T).

Emticicia soli sp. nov., a novel member of the family 'Flexibacteraceae', isolated from tetrabromobisphenol A-contaminated soil

Bacterial strain ZZ-4T, a Gram-stain-negative, aerobic, non-spore-forming, non-motile, non-flagellated, rod-shaped bacterium, was isolated from tetrabromobisphenol A-contaminated soil in PR China. The taxonomic position of this strain was investigated using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain ZZ-4T was a member of the genus Emticicia and showed the highest sequence similarity to Emticicia fontis IMCC1731T (98.0 %) and Emticicia ginsengisoli Gsoil 085T (97.2 %), and lower (<97 %) sequence similarity to other known Emticicia species. Chemotaxonomic analysis revealed that strain ZZ-4T possessed menaquinone MK-7 as the major isoprenoid quinone; and iso-C15 : 0, summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7), iso-C17 : 0 3-OH and C16 : 1ω5c were the predominant fatty acids. Strain ZZ-4T showed low DNA-DNA relatedness with E. fontis IMCC1731T (39.8±3.1 %) and E. ginsengisoli Gsoil 085T (44.51±1.5 %). The DNA G+C content was 38.3 mol%. Based on the phylogenetic and phenotypic characteristics, chemotaxonomic data and DNA-DNA hybridization results, strain ZZ-4T is considered to represent a novel species of the genus Emticicia, for which the name Emticicia soli sp. nov. is proposed. The type strain is ZZ-4T (=KCTC 52344T=CCTCC AB 2016137T).

Arcticibacterium luteifluviistationis gen. nov., sp. nov., isolated from Arctic seawater

A Gram-staining-negative, aerobic, non-motile and yellow-pigmented bacterium, designated strain SM1504T, was isolated from Arctic seawater. It hydrolysed aesculin and gelatin but did not reduce nitrate to nitrite. Phylogenetic analysis of 16S rRNA gene sequences revealed that strain SM1504T constituted a distinct phylogenetic line within the family Cytophagaceae and was closely related to species of the genera Lacihabitans, Emticicia, Fluviimonas and Leadbetterella, with respect to which low sequence similarities between 88.9 and 91.6 % were observed. The major fatty acids of strain SM1504T were summed feature 3 (comprising C16 : 1ω7c and/or iso-C15 : 0 2-OH) and iso-C15 : 0. The predominant polar lipids of strain SM1504T were phosphatidylethanolamine and one unidentified lipid. The only respiratory quinone detected in strain SM1504T was MK7. The DNA G+C content of strain SM1504T was 40.8 mol%. On the basis of the phylogenetic, chemotaxonomic and phenotypic characterization in this study, strain SM1504T is considered to represent a novel species in a new genus of the family Cytophagaceae, for which the name Arcticibacterium luteifluviistationis gen. nov., sp. nov. is proposed. The type strain is SM1504T (=KCTC 42716T=CCTCC AB 2015348T).

Emticicia aquatilis sp. nov., isolated from a freshwater sample

A Gram-stain-negative, facultatively anaerobic, non-motile, rod-shaped and yellow-pigmented bacterium, designated strain THG-DN6.14T, was isolated from a freshwater sample near Donghaksa temple in Daejeon, South Korea. On the basis of the results of 16S rRNA gene sequence comparisons, THG-DN6.14T was found to be most closely related to Emticicia sediminis JBR12T (99.1 % sequence similarity), Emticicia oligotrophica DSM 17448T (97.6 %), Emticicia aquatica HMF2925T (96.5 %), and Emticicia ginsengisoliGsoil 085T (94.4 %). The DNA-DNA relatedness between THG-DN6.14T and its phylogenetically closest neighbours was below 65.0 %. The DNA G+C content was 43.3 mol%. The major polar lipids were found to be phosphatidylethanolamine, an unidentified glycolipid and an unidentified aminoglycolipid. The major fatty acids were identified as C16 : 0, iso-C15 : 0, iso-C17 : 0 3-OH, and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The respiratory quinone was menaquinone MK-7. These data supported the affiliation of THG-DN6.14T to the genus Emticicia. THG-DN6.14Tcould be distinguished from related species of the genus Emticicia by physiological and biochemical tests. Therefore, the novel isolate represents a novel species, for which the name Emticicia aquatilis sp. nov. is proposed, with THG-DN6.14T (=KACC 18540T=CGMCC 1.15958T) as the type strain.

Emticiciafontis sp. nov., isolated from a freshwater pond

A bacterial strain, designated IMCC1731T, was isolated from an eutrophic freshwater pond and characterized using a polyphasic taxonomic approach. Cellular growth occurred at pH 6-9 (optimum, pH 8.0), at 10-30 °C (optimum, 25 °C) and with 0-1 % (w/v) NaCl (optimum, 0 %). Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain IMCC1731T belonged to the genus Emticicia in the family Cytophagaceae and was most closely related to Emticicia ginsengisoli Gsoil 085T (98.1 %) followed by Emticicia paludis HMF3850T (95.0 %), Emticicia oligotrophica DSM 17448T (94.7 %), Emticicia aquatica HMF2925T (94.4 %) and Emticicia sediminis JBR12T (94.0 %). The DNA-DNA relatedness between strain IMCC1731T and E. ginsengisoli Gsoil 085T was 47±4 %. The DNA G+C content of strain IMCC1731T was 37.7 mol%. The predominant cellular fatty acids were summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) and iso-C15 : 0. Based on the physiological and chemotaxonomic characteristics, DNA-DNA relatedness and 16S rRNA gene phylogeny, stain IMCC1731T is considered to represent a novel species of the genus Emticicia, for which the name Emticicia fontis sp. nov. is proposed. The type strain is IMCC1731T (=KCTC 52248T=JCM 31373T).

Emticicia paludis sp. nov., isolated from wetland freshwater

A novel bacterium, designated HMF3850T, was isolated from freshwater collected from the Gyeong-an wetland, Republic of Korea. Cells were Gram-stain-negative, aerobic, straight rods, non-motile, and oxidase- and catalase-positive. Growth was observed at pH 6.0-8.0 and at 10-30 °C on R2A agar. Comparative analysis of 16S rRNA gene sequences revealed that strain HMF3850T is a member of the genus Emticicia, sharing highest sequence similarities with Emticicia aquatica HMF2925T (96.7 % 16S rRNA gene sequence similarity), Emticicia sediminis JBR12T (95.0 %), Emticicia ginsengisoliGsoil 085T (94.9 %) and Emticicia oligotrophica DSM 17448T (94.7 %). The major fatty acids were iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The predominant respiratory quinone was MK-7. The major polar lipids were phosphatidylethanolamine, phosphatidylinositol, one unidentified aminophospholipid, two unidentified aminolipids and eight unidentified polar lipids. The DNA G+C content was 38.5 mol %. On the basis of the evidence presented in this study, strain HMF3850T represents a novel species of the genus Emticicia, for which the name Emticicia paludis sp. nov. is proposed. The type strain is HMF3850T (=KCTC 42851T=CECT 9087T).

Microbiological mechanism of the improved nitrogen and phosphorus removal by embedding microbial fuel cell in Anaerobic-Anoxic-Oxic wastewater treatment process

Anaerobic-Anoxic-Oxic (AA/O) wastewater treatment process is a widely used wastewater treatment process for simultaneous nitrogen and phosphorus removal. Microbial fuel cell (MFC) can generate electricity and treat the organic wastewater simultaneously. Our previous research showed that embedding MFC in AA/O wastewater treatment process could enhance the pollutants removal efficiency. However, the mechanism was not clear. In this study, a lab-scale corridor-style AA/O reactor with MFC embedded was operated and both the total nitrogen and total phosphorus removal efficiencies were enhanced. DGGE and Illumina Miseq results demonstrated that both the microbial community structures on the surface of the cathode and in the suspensions of cathode chamber have been changed. The percentage of Thauera and Emticicia, identified as denitrifying bacteria, increased significantly in the suspension liquid when the MFC was embedded in the AA/O reactor. Moreover, the genus Rheinheimera were significantly enriched on the cathode surface, which might contribute to both the nitrogen removal enhancement and electricity generation.

Taeseokella kangwonensis gen. nov., sp. nov., isolated from a freshwater reservoir

A Gram-stain-negative, non-motile and yellow-pigmented bacterium, designated HME8275T, was isolated from freshwater in Korea. The major fatty acids of strain HME8275T were summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c), C16 : 0 and iso-C15 : 0. The only respiratory quinone was MK-7. Polar lipid analysis showed phosphatidylethanolamine, two unidentified aminolipids, two unidentified aminophospholipids and three unidentified polar lipids. The DNA G+C content of strain HME8275T was 37.6 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain HME8275T formed a lineage within the family Cytophagaceae and was related to Lacihabitans soyangensis HME6675T (92.6 % 16S rRNA gene sequence similarity), Leadbetterella byssophila 4M15T (89.0 %), Fluviimonas pallidilutea TQQ6T (89.7 %) and Emticicia oligotrophica GPTSA100-15T (89.8 %). On the basis of the evidence presented in this study, strain HME8275T represents a novel species of a new genus in the family Cytophagaceae, for which the name Taeseokella kangwonensis, gen. nov., sp. nov. is proposed. The type strain of the type species is HME8275T ( = KACC 16933T = CECT 8198T).

Emticicia aquatica sp. nov., a species of the family Cytophagaceae isolated from fresh water

A Gram-staining-negative, non-gliding, orange-pigmented bacterial strain, designated HMF2925T, was isolated from fresh water in Korea. The phylogenetic tree based on 16S rRNA gene sequences showed that strain HMF2925T formed a distinct lineage within the genus Emticicia. Strain HMF2925T was closely related to Emticicia oligotrophica DSM 17448T (95.5 %) and Emticicia ginsengisoli Gsoil 085T (94.1 %). The major fatty acids of strain HMF2925T were summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), iso-C15 : 0, C16 : 1ω5c and C16 : 0.The major polar lipids of strain HMF2925T were phosphatidylethanolamine, phosphatidylinositol, diphosphatidylglycerol, phosphatidylglycerol, an unidentified glycolipid, two unidentified amino lipids and three unidentified polar lipids. The DNA G+C content of strain HMF2925T was 36.5 mol%. On the basis of the evidence presented in this study, strain HMF2925T represents a novel species of the genus Emticicia, for which the name Emticicia aquatica sp. nov. is proposed. The type strain is HMF2925T ( = KCTC 42574T = CECT 8858T).

Impact of manufactured TiO2 nanoparticles on planktonic and sessile bacterial communities

In the present study, we conducted a 2 week microcosm experiment with a natural freshwater bacterial community to assess the effects of titanium dioxide nanoparticles (TiO2-NPs) at various concentrations (0, 1, 10 and 100 mg/L) on planktonic and sessile bacteria under dark conditions. Results showed an increase of planktonic bacterial abundance at the highest TiO2-NP concentration, concomitant with a decrease from that of sessile bacteria. Bacterial assemblages were most affected by the 100 mg/L TiO2-NP exposure and overall diversity was found to be lower for planktonic bacteria and higher for sessile bacteria at this concentration. In both compartments, a 100 mg/L TiO2-NPs exposure induced a decrease in the ratio between the Betaproteobacteria and Bacteroidetes. For planktonic communities, a decrease of Comamonadaceae was observed concomitant with an increase of Oxalobacteraceae and Cytophagaceae (especially Emticicia). For sessile communities, results showed a strong decrease of Betaproteobacteria and particularly of Comamonadaceae.

Emticicia sediminis sp. nov. isolated from sediment of a shallow stream

A novel bacterial strain, designated JBR12T, was isolated from sediment of a shallow stream in Cheonan, Korea. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain JBR12T belongs to the genus Emticicia, and indicated that its closest relatives are Emticicia oligotrophica DSM 17448T (97.8 % sequence similarity) and E. ginsengisoli Gsoil 085T (94.3%). A DNA-DNA hybridization experiment revealed < 70 % genomic relatedness between strain JBR12T and E. oligotrophica DSM 17448T. The major fatty acids (>5% of the total) were iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C15 : 0 3-OH, anteiso-C15 : 0 and iso-C15 : 0 3-OH. The DNA G+C content of strain JBR12T was 37.7 mol%. According to data from the present polyphasic taxonomic study, strain JBR12T represents a novel species of the genus Emticicia, for which the name Emticicia sediminis sp. nov. is proposed. The type strain is JBR12T ( = KACC 17466T = JCM 19321T).

Effects of a ciliate protozoa predator on microbial communities in pitcher plant (Sarracenia purpurea) leaves

The aquatic communities found within the water filled leaves of the pitcher plant, Sarracenia purpurea, have a simple trophic structure providing an ideal system to study microscale interactions between protozoan predators and their bacterial prey. In this study, replicate communities were maintained with and without the presence of the bactivorous protozoan, Colpoda steinii, to determine the effects of grazing on microbial communities. Changes in microbial (Archaea and Bacteria) community structure were assessed using iTag sequencing of 16S rRNA genes. The microbial communities were similar with and without the protozoan predator, with>1000 species. Of these species, Archaea were negligible, with Bacteria comprising 99.99% of the microbial community. The Proteobacteria and Bacteroidetes were the most dominant phyla. The addition of a protozoan predator did not have a significant effect on microbial evenness nor richness. However, the presence of the protozoan did cause a significant shift in the relative abundances of a number of bacterial species. This suggested that bactivorous protozoan may target specific bacterial species and/or that certain bacterial species have innate mechanisms by which they evade predators. These findings help to elucidate the effect that trophic structure perturbations have on predator prey interactions in microbial systems.

Lacihabitans soyangensis gen. nov., sp. nov., a new member of the family Cytophagaceae, isolated from a freshwater reservoir

A Gram-staining-negative, non-motile and orange-pigmented bacterium, designated strain HME6675T, was isolated from freshwater of a reservoir in Korea. The major fatty acids of strain HME6675T were iso-C15 : 0 (33.4 %) and summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c; 31.3 %). The major respiratory quinone was MK-7. The polar lipids were phosphatidylethanolamine, one unidentified aminolipid, one unidentified aminophospholipid and three unidentified polar lipids. The DNA G+C content of strain HME6675T was 37.7 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain HME6675T formed a lineage within the family Cytophagaceae and was related to Leadbetterella byssophila 4M15T (93.0 % sequence similarity), Fluviimonas pallidilutea TQQ6T (90.6 %) and Emticicia oligotrophica GPTSA100-15T (89.1 %). On the basis of the evidence presented in this study, strain HME6675T represents a novel genus and species of the family Cytophagaceae , for which the name Lacihabitans soyangensis gen. nov., sp. nov. is proposed. The type strain of Lacihabitans soyangensis is HME6675T ( = KCTC 23259T = CECT 7826T).

Fluviimonas pallidilutea gen. nov., sp. nov., a new member of the family Cytophagaceae isolated from a freshwater river

A bacterial strain designated TQQ6T was isolated from a freshwater river in Taiwan and characterized using a polyphasic taxonomy approach. Cells of strain TQQ6T were strictly aerobic, Gram-staining-negative, poly-β-hydroxybutyrate-containing, non-motile, non-spore-forming, long rods surrounded by a thick capsule and forming pale orange colonies. Growth occurred at 20–40 °C (optimum, 25 °C), at pH 7.0–9.0 (optimum, pH 8.0) and with 0–0.5 % NaCl (optimum, 0 %). The predominant fatty acids were iso-C15 : 0, summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c), iso-C17 : 0 3-OH, C16 : 1ω5c and C16 : 0. The major isoprenoid quinone was MK-7 and the DNA G+C content was 42.2 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylcholine, two uncharacterized aminophospholipids and three uncharacterized phospholipids. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain TQQ6T represents a distinct phyletic line that reflects a novel generic status within the family Cytophagaceae with relatively low sequence similarities (less than 90 %) to members of other genera with validly published names. On the basis of the genotypic and phenotypic data, strain TQQ6T represents a new genus and novel species of the family Cytophagaceae , for which the name Fluviimonas pallidilutea gen. nov., sp. nov. is proposed. The type strain is TQQ6T ( = BCRC 80447T = LMG 27056T = KCTC 32035T).

Complete genome sequence of Leadbetterella byssophila type strain (4M15)

Leadbetterella byssophila Weon et al. 2005 is the type species of the genus Leadbetterella of the family Cytophagaceae in the phylum Bacteroidetes. Members of the phylum Bacteroidetes are widely distributed in nature, especially in aquatic environments. They are of special interest for their ability to degrade complex biopolymers. L. byssophila occupies a rather isolated position in the tree of life and is characterized by its ability to hydrolyze starch and gelatine, but not agar, cellulose or chitin. Here we describe the features of this organism, together with the complete genome sequence, and annotation. L. byssophila is already the 16^th member of the family Cytophagaceae whose genome has been sequenced. The 4,059,653 bp long single replicon genome with its 3,613 protein-coding and 53 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.

Endosymbiotic bacteria in the parasitic ciliate Ichthyophthirius multifiliis

Endosymbiotic bacteria were identified in the parasitic ciliate Ichthyophthirius multifiliis, a common pathogen of freshwater fish. PCR amplification of DNA prepared from two isolates of I. multifiliis, using primers that bind conserved sequences in bacterial 16S rRNA genes, generated an approximately 1,460-bp DNA product, which was cloned and sequenced. Sequence analysis demonstrated that 16S rRNA gene sequences from three classes of bacteria were present in the PCR product. These included Alphaproteobacteria (Rickettsiales), Sphingobacteria, and Flavobacterium columnare. DAPI (4',6-diamidino-2-phenylindole) staining showed endosymbionts dispersed throughout the cytoplasm of trophonts and, in most, but not all theronts. Endosymbionts were observed by transmission electron microscopy in the cytoplasm, surrounded by a prominent, electron-translucent halo characteristic of Rickettsia. Fluorescence in situ hybridization demonstrated that bacteria from the Rickettsiales and Sphingobacteriales classes are endosymbionts of I. multifiliis, found in the cytoplasm, but not in the macronucleus or micronucleus. In contrast, F. columnare was not detected by fluorescence in situ hybridization. It likely adheres to I. multifiliis through association with cilia. The role that endosymbiotic bacteria play in the life history of I. multifiliis is not known.