Lacisediminihabitans profunda gen. nov., sp. nov., a member of the family Microbacteriaceae isolated from freshwater sediment

A novel Gram-stain-positive bacterial strain, CHu50b-6-2^T, was isolated from a 67-cm-long sediment core collected from the Daechung Reservoir at a water depth of 17 m, Daejeon, Republic of Korea. The cells of strain CHu50b-6-2^T were aerobic non-motile and formed yellow colonies on R2A agar. The phylogenetic analysis based on 16S rRNA gene sequencing indicated that the strain formed a separate lineage within the family Microbacteriaceae, exhibiting 98.0%, 97.7% and 97.6% 16S rRNA gene sequence similarities to Glaciihabitans tibetensis KCTC 29148^T, Frigoribacterium faeni KACC 20509^T and Lysinibacter cavernae DSM 27960^T, respectively. The phylogenetic trees revealed that strain CHu50b-6-2^T did not show a clear affiliation to any genus within the family Microbacteriaceae. The chemotaxonomic results showed B1α type peptidoglacan containg 2, 4-diaminobutyric acid (DAB) as the diagnostic diamino acid, MK-10 as the predominant respiratory menaquinone, diphosphatidylglycerol, phosphatidylglycerol, and an unidentified glycolipid as the major polar lipids, anteiso-C_15:0, iso-C_16:0, and anteiso-C_17:0 as the major fatty acids, and a DNA G + C content of 67.3 mol%. The combined genotypic and phenotypic data showed that strain CHu50b-6-2^T could be distinguished from all genera within the family Microbacteriaceae and represents a novel genus, Lacisediminihabitans gen. nov., with the name Lacisediminihabitans profunda sp. nov., in the family Microbacteriaceae. The type strain is CHu50b-6-2^T (= KCTC 49081^T = JCM 32673^T).

Maximizing biomass and lipid production in Ettlia sp. by ultraviolet stress in a continuous culture

Lipid production in microalgae can be induced by various stress factors. However, stress induced lipid accumulation requires considerable time leading to the decrease in lipid productivity. Here, we attempted to increase the lipid productivity while maintaining the high growth of Ettlia sp. by optimizing nitrogen concentration and UV exposure in a continuous culture. The biomass and lipid productivities of Ettlia sp. cultured with 150 mg N L^-1 and UV-A added PAR were 1.67 ± 0.08 g L^-1 d^-1 and 0.55 ± 0.05 g L^-1 d^-1, respectively. Lipid productivity and lipid content were around 43.7% and 33.7% higher, respectively in UV-A treatment compared to the control. Moreover, gene-expression patterns related to antioxidant defense and intracellular ROS levels indicated that UV-A affected certain ROS and antioxidants pathways and successfully induced the lipid accumulation in Ettlia sp. This strategy to activate lipid accumulation can be applied in other microalgae without affecting their growth.

Characterization of Distinct CyanoHABs-Related Modules in Microbial Recurrent Association Network

To elucidate the interspecies connectivity between cyanobacteria and other bacteria (non-cyanobacteria) during cyanobacterial harmful algal blooms (cyanoHABs), samples were collected from the Nakdong River, Korea, from June 2016 to August 2017, and microbial recurrent association network (MRAN) analysis was performed to overcome the limitations of conventional network analysis. Microcystis blooms were tightly linked with Pseudanabaena in summer and were accompanied by significant changes in the non-cyanobacterial community composition (nCCC) compared to non-bloom period. Riverine bacterial communities could be clearly separated into modules that were involved in the formation, maintenance, and decomposition of cyanoHABs. Roseomonas and Herbaspirillum were directly linked with major cyanobacteria and assigned to connector and module hub in cyanoHABs-related modules, respectively. The functional profiles of the cyanoHABs-related modules suggested that nitrate reduction, aerobic ammonia oxidation, fermentation, and hydrocarbon degradation could be increased during the Microcystis bloom periods. In conclusion, MRAN analysis revealed that specific bacteria belonging to cyanoHABs-related module, including connectors and module hubs, appeared to contribute to the development and collapse of cyanoHABs. Therefore, to understand cyanoHABs, a modular microbial perspective may be more helpful than a single bacterial species perspective.

Description of novel members of the family Sphingomonadaceae: Aquisediminimonas profunda gen. nov., sp. nov., and Aquisediminimonas sediminicola sp. nov., isolated from freshwater sediment

Two Gram-stain-negative bacterial strains, DS48-3^T and CH68-4^T, were isolated from freshwater sediment taken from the Daechung Reservoir, Republic of Korea. Cells of strains DS48-3^T and CH68-4^T were aerobic, non-motile, non-spore-forming and rod-shaped. Strain DS48-3^T was isolated from a sediment surface sample at a depth of 48 m from the Daechung Reservoir and was most closely related to the genus Sphingopyxis according to 16S rRNA gene sequence analysis (94.5-95.9 % similarity). Strain CH68-4^T was isolated from the very bottom of a 67-cm-long sediment core collected from Daechung Reservoir at a water depth of 17 m and was most closely related to the genus Sphingopyxis (16S rRNA gene sequence similarity of 93.7-95.0 %). Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the two strains formed a separate lineage within the order Sphingomonadales showing similarity values below 95.9 % with their closest phylogenetic neighbours, and sharing 97.3 % similarity with each other. The combined genotypic and phenotypic data showed that strains DS48-3^T and CH68-4^T could be distinguished from all genera within the family Sphingomonadaceae and represented two distinct species of a novel genus, Aquisediminimonas profunda gen. nov., sp. nov. (type strain DS48-3^T=KCTC 52068^T=CCTCC AB 2018061^T) and Aquisediminimonas sediminicola sp. nov. (type strain CH68-4^T=KCTC 62205^T=CCTCC AB 2018062^T).

Fuel-Composition Dependent Reactor Antineutrino Yield at RENO

We report a fuel-dependent reactor electron antineutrino (ν[over ¯]_{e}) yield using six 2.8 GW_{th} reactors in the Hanbit nuclear power plant complex, Yonggwang, Korea. The analysis uses 850 666 ν[over ¯]_{e} candidate events with a background fraction of 2.0% acquired through inverse beta decay (IBD) interactions in the near detector for 1807.9 live days from August 2011 to February 2018. Based on multiple fuel cycles, we observe a fuel ^{235}U dependent variation of measured IBD yields with a slope of (1.51±0.23)×10^{-43}  cm^{2}/fission and measure a total average IBD yield of (5.84±0.13)×10^{-43}  cm^{2}/fission. The hypothesis of no fuel-dependent IBD yield is ruled out at 6.6σ. The observed IBD yield variation over ^{235}U isotope fraction does not show significant deviation from the Huber-Mueller (HM) prediction at 1.3 σ. The measured fuel-dependent variation determines IBD yields of (6.15±0.19)×10^{-43} and (4.18±0.26)×10^{-43}  cm^{2}/fission for two dominant fuel isotopes ^{235}U and ^{239}Pu, respectively. The measured IBD yield per ^{235}U fission shows the largest deficit relative to the HM prediction. Reevaluation of the ^{235}U IBD yield per fission may mostly solve the reactor antineutrino anomaly (RAA) while ^{239}Pu is not completely ruled out as a possible contributor to the anomaly. We also report a 2.9 σ correlation between the fractional change of the 5 MeV excess and the reactor fuel isotope fraction of ^{235}U.

Nevskia lacus sp. nov., a gammaproteobacterium isolated from a eutrophic lake

A novel Gram-stain negative, rod-shaped and motile bacterial strain, designated strain Seoho-38^T, was isolated from a eutrophic lake in South Korea. Polyphasic taxonomic studies were performed to investigate the taxonomic position of the new isolate. The phylogenetic analysis based on the 16S rRNA gene sequences revealed that strain Seoho-38^T formed a distinct cluster with Nevskia ramosa Soe1^T, Nevskia persephonica G6M-30^T, Nevskia soli GR15-1^T, Nevskia terrae KIS13-15^T and Nevskia aquatilis F2-63^T with bootstrap resampling value of 100%. Of those Nevskia strains, the new isolate shows high sequence similarity with N. ramosa Soe1^T (98.7%) and N. persephonica G6M-30^T (97.2%), and values lower than 96.5% with the other type strains. The new isolate was observed to grow aerobically in 0-1.5% (w/v) NaCl (optimum 0%), at pH 7.0-9.0 (optimum pH 7.0) and temperature 15-36 °C (optimum 20-30 °C) on R2A medium. DNA-DNA relatedness values between strain Seoho-38^T and the type strains of reference species in the genus Nevskia were < 24%. The genomic DNA G + C content was determined to be 67.4 mol%. Ubiquinone-8 (Q-8) (95%) and ubiquinone-7 (Q-7) (5%) were identified as the respiratory quinones. The cellular polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, a phosphoaminolipid, two glycolipids, an aminolipid and four unidentified lipids. The major fatty acid components were found to include summed feature 3 (C_16:1ω7c and/or C_16:1ω6c), summed feature 8 (C_18:0ω7c and/or C_18:0ω6c), C_16:0 and C_14:0. Based on the above polyphasic evidence, strain Seoho-38^T (= KCTC 52221^T = JCM 31888^T) represents a new species of the genus Nevskia, for which the name Nevskia lacus sp. nov. is proposed.

Measurement of Reactor Antineutrino Oscillation Amplitude and Frequency at RENO

The RENO experiment reports more precisely measured values of θ_{13} and |Δm_{ee}^{2}| using ∼2200 live days of data. The amplitude and frequency of reactor electron antineutrino (ν[over ¯]_{e}) oscillation are measured by comparing the prompt signal spectra obtained from two identical near and far detectors. In the period between August 2011 and February 2018, the far (near) detector observed 103 212 (850 666) ν[over ¯]_{e} candidate events with a background fraction of 4.8% (2.0%). A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the measured number of ν[over ¯]_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.0896±0.0048(stat)±0.0047(syst) and |Δm_{ee}^{2}|=[2.68±0.12(stat)±0.07(syst)]×10^{-3}  eV^{2}.

Investigation of multifilament MgB2 superconducting joint technique for development of MRI magnets

This study presents the investigation of superconducting joints fabricated using multifilament magnesium diboride (MgB₂) wires for the development of persistent-current mode magnetic resonance imaging (MRI) magnets. The critical current of the jointed samples decreased with increasing cutting angle because the smaller cutting angle allowed greater exposure of the MgB₂ filament, thereby increasing the contact area for the wire-bulk-wire connection. In addition, an appropriate pressing pressure (300 MPa) was necessary to establish the multifilament MgB₂ joint without significant degradation of superconducting properties. The resistance of the optimal MgB₂ joint, measured using the field-decay technique, was <1.5 × 10^-14 Ω. Therefore, the proposed joint technique can be employed for developing multifilament MgB₂ MRI magnets operating in the persistent-current mode.

Flavihumibacter profundi sp. nov., isolated from eutrophic freshwater sediment

A Gram-stain-positive, aerobic, non-motile, non-spore-forming, and rod-shaped bacterium, designated strain CHu64-6-1^T, was isolated from a 67-cm-long sediment core collected from the Daechung Reservoir at a water depth of 17-m in Daejeon, Republic of Korea. Comparative 16S rRNA gene sequence studies placed the new isolate in the class Sphingobacteriia, and the isolate is notably most closely related to Flavihumibacter sediminis CJ663^T (98.1% similarity), Flavihumibacter solisilvae 3-3^T (97.8%), Flavihumibacter petaseus T41^T (97.5%), Flavihumibacter cheonanensis WS16^T (97.4%), and Flavihumibacter stibioxidans YS-17^T (97.2%). The cells of strain CHu64-6-1^T formed yellow colonies on R2A agar and contained MK-7 as the only menaquinone, phosphatidylethanolamine, an unidentified phospholipid, and two unidentified aminolipids as the major polar lipids, and C_15:0 iso, C_17:0 iso 3-OH, C_15:1 iso G, and C_16:1ω5c as the major fatty acids (> 5%). The DNA G + C content of the genome was determined to be 46.5 mol%. The DNA-DNA hybridization values of strain CHu64-6-1^T with F. sediminis CJ663^T, F. solisilvae 3-3^T, F. petaseus T41^T, F. cheonanensis WS16^T, and F. stibioxidans YS-17^T were 12.4-33.2%. Based on the combined genotypic and phenotypic data, we propose that strain CHu64-6-1^T represents a novel species of the genus Flavihumibacter, for which the name Flavihumibacter profundi sp. nov. is proposed. The type strain is CHu64-6-1^T (= KCTC 62290^T = CCTCC AB 2018060^T).

Description of Hymenobacter daejeonensis sp. nov., isolated from grass soil, based on multilocus sequence analysis of the 16S rRNA gene, gyrB and tuf genes

A polyphasic taxonomic study was carried out on strains PB105^T and PB108 isolated from a grass soil in Korea. The cells of the strains were Gram-stain negative, non-spore-forming, non-motile, and rod-shaped. Comparative 16S rRNA gene sequence studies showed a clear affiliation of these strains with Bacteroidetes, which showed high pairwise sequence similarities with Hymenobacter algoricola VUG-A23a^T (99.2%), Hymenobacter fastidiosus VUG-A124a^T (97.4%), and Hymenobacter daecheongensis Dae14^T (96.9%). The phylogenetic analysis based on 16S rRNA gene sequences showed that the strains formed a clear phylogenetic lineage with the genus Hymenobacter. The major fatty acids were identified as C_15:0 iso, C_15:0 anteiso, C_16:1 ω5c, C_15:0 iso 3-OH, C_17:0 iso 3-OH, summed feature 3 (C_16:1 ω6c and/or C_16:1 ω7c/t), and summed feature 4 (C_17:1 anteiso B and/or C_17:1 iso I). The major cellular polar lipids were identified as phosphatidylethanolamine, an unidentified aminolipid, and two unidentified lipids. The respiratory quinone was identified as MK-7 and the genomic DNA G+C content was determined to be 64.5 mol% for strain PB105^T and 64.1 mol% for strain PB108. DNA-DNA hybridization value of type strain PB105^T with H. algoricola VUG-A23a^T was 32.3% (reciprocal 39.2). Based on the combined genotypic and phenotypic data, we propose that strains PB105^T and PB108 represent a novel species of the genus Hymenobacter, for which the name Hymenobacter daejeonensis sp. nov. is proposed. The type strain is PB105^T (= KCTC 52579^T = JCM 31885^T).

Current status and perspectives of genome editing technology for microalgae

Genome editing techniques are critical for manipulating genes not only to investigate their functions in biology but also to improve traits for genetic engineering in biotechnology. Genome editing has been greatly facilitated by engineered nucleases, dubbed molecular scissors, including zinc-finger nuclease (ZFN), TAL effector endonuclease (TALEN) and clustered regularly interspaced palindromic sequences (CRISPR)/Cas9. In particular, CRISPR/Cas9 has revolutionized genome editing fields with its simplicity, efficiency and accuracy compared to previous nucleases. CRISPR/Cas9-induced genome editing is being used in numerous organisms including microalgae. Microalgae have been subjected to extensive genetic and biological engineering due to their great potential as sustainable biofuel and chemical feedstocks. However, progress in microalgal engineering is slow mainly due to a lack of a proper transformation toolbox, and the same problem also applies to genome editing techniques. Given these problems, there are a few reports on successful genome editing in microalgae. It is, thus, time to consider the problems and solutions of genome editing in microalgae as well as further applications of this exciting technology for other scientific and engineering purposes.

EphrinB1 promotes cancer cell migration and invasion through the interaction with RhoGDI1

Eph receptors and their corresponding ephrin ligands have been associated with regulating cell–cell adhesion and motility, and thus have a critical role in various biological processes including tissue morphogenesis and homeostasis, as well as pathogenesis of several diseases. Aberrant regulation of Eph/ephrin signaling pathways is implicated in tumor progression of various human cancers. Here, we show that a Rho family GTPase regulator, Rho guanine nucleotide dissociation inhibitor 1 (RhoGDI1), can interact with ephrinB1, and this interaction is enhanced upon binding the extracellular domain of the cognate EphB2 receptor. Deletion mutagenesis revealed that amino acids 327–334 of the ephrinB1 intracellular domain are critical for the interaction with RhoGDI1. Stimulation with an EphB2 extracellular domain-Fc fusion protein (EphB2-Fc) induces RhoA activation and enhances the motility as well as invasiveness of wild-type ephrinB1-expressing cells. These Eph-Fc-induced effects were markedly diminished in cells expressing the mutant ephrinB1 construct (Δ327–334) that is ineffective at interacting with RhoGDI1. Furthermore, ephrinB1 depletion by siRNA suppresses EphB2-Fc-induced RhoA activation, and reduces motility and invasiveness of the SW480 and Hs578T human cancer cell lines. Our study connects the interaction between RhoGDI1 and ephrinB1 to the promotion of cancer cell behavior associated with tumor progression. This interaction may represent a therapeutic target in cancers that express ephrinB1.

Blastomonas fulva sp. nov., aerobic photosynthetic bacteria isolated from a Microcystis culture

Two Gram-stain-negative, aerobic, non-motile, non-spore-forming and rod-shaped bacteria, designated strains T2T and T5, were isolated from a culture of Microcystis from Daejeon, Republic of Korea. Comparative 16S rRNA gene sequence studies placed the new isolates in the class Alphaproteobacteria and, notably, most closely related to Blastomonasaquatica PE 4-5T, Blastomonas natatoria DSM 3183T and Blastomonas ursincola KR-99T showing 99.4 %, 98.2 % and 97.9 % 16S rRNA gene sequence similarities, respectively. The two novel strains shared 100 % similarity with each other. The cells of strains T2T and T5 formed yellow colonies on R2A agar and contained Q-10 as the only ubiquinone, sphingoglycolipid, phosphatidylethanolamine, phosphatidylcholine, and phosphatidylglycerol as major polar lipids, and C17 : 1ω6c, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C17 : 1ω8c and C17 : 0 as the major fatty acids (>5 %). The DNA G+C content of the genomes was determined to be 64.2 mol% for strain T2T and 64.4 mol% for strain T5. The DNA-DNA hybridization values of strains T2T and T5 with B.aquatica PE 4-5T, B. natatoria DSM 3183T, and B. ursincola KR-99T were 19.7-42.4 %. Based on the combined genotypic and phenotypic data, we propose that strains T2T and T5 represent a novel species of the genus Blastomonas, for which the name Blastomonas fulvasp. nov. is proposed. The type strain is T2T (=KCTC 42354T=JCM 30467T).

VUV spectroscopy in impurity injection experiments at KSTAR using prototype ITER VUV spectrometer

The ITER vacuum ultra-violet (VUV) core survey spectrometer has been designed as a 5-channel spectral system so that the high spectral resolving power of 200-500 could be achieved in the wavelength range of 2.4-160 nm. To verify the design of the ITER VUV core survey spectrometer, a two-channel prototype spectrometer was developed. As a subsequent step of the prototype test, the prototype VUV spectrometer has been operated at KSTAR since the 2012 experimental campaign. From impurity injection experiments in the years 2015 and 2016, strong emission lines, such as Kr xxv 15.8 nm, Kr xxvi 17.9 nm, Ne vii 46.5 nm, Ne vi 40.2 nm, and an array of largely unresolved tungsten lines (14-32 nm) could be measured successfully, showing the typical photon number of 10¹³-10¹⁵ photons/cm² s.

Note: Progress on the use of MgB2 superconducting joint technique for the development of MgB2 magnets for magnetic resonance imaging (MRI)

This note presents a superconducting joint technique for the development of MgB₂ magnetic resonance imaging (MRI) magnets. The MgB₂ superconducting joint was fabricated by a powder processing method using Mg and B powders to establish a wire-bulk-wire connection. The joint resistance measured using a field-decay method was <10^-14 Ω, demonstrating that the proposed joint technique could be employed for developing "next-generation" MgB₂ MRI magnets operating in the persistent current mode.

Abundant iron and sulfur oxidizers in the stratified sediment of a eutrophic freshwater reservoir with annual cyanobacterial blooms

The microbial community in eutrophic freshwater sediment was investigated from a 67-cm-deep sediment core collected from the Daechung Reservoir in South Korea, where cyanobacterial blooms have occurred annually for the past 30 years. The majority of core sediments were characterized by dark-grayish, fine-grained mud with abundant gas-escaped and thinly laminated layers. Intervals of summer and winter seasons were represented by periodic peaks of geochemical profiles of parameters such as grain size and relative carbon mass ratios to various nutrients such as nitrogen, sulfur, and phosphorus. In bacteria, Proteobacteria (66.6%) was the most prevalent phylum, followed by Chloroflexi (8.9%), Bacteroidetes (5.1%), and Spirochaetes (2.6%). Archaea were also abundant, representing approximately half of the total prokaryotes in the sediments. Notably, three Bacteria (Sulfuricurvum, Sideroxydans, and Gallionella) and one Archaea (Thermoplasmata) accounted for 43.4% and 38.4% of the total bacteria and archaea, respectively, implying that iron and sulfur oxidizing microorganisms dominate in this eutrophic freshwater sediment. These results indicate that 1) eutrophic freshwater lakes in monsoon climates undergo a stratified sedimentary process with seasonal and annual variations in geochemical and microbial profiles, and 2) the microbial oxidative metabolism of iron and sulfur is notably active in sediments from a eutrophic lake.

Actinotalea caeni sp. nov., isolated from a sludge sample of a biofilm reactor

A polyphasic taxonomic study was carried out on strain EBR-4-2T isolated from a biofilm reactor in Korea. Cells of the strain were Gram-stain-positive, non-spore-forming, non-motile and rod-shaped. Comparative 16S rRNA gene sequence studies showed the clear affiliation of this strain to the Actinobacteria, and it had the highest pairwise sequence similarities with Actinotalea suaedae EGI 60002T (98.7 %), Actinotalea ferrariae CF5-4T (96.3 %) and Actinotalea fermentans DSM 3133T (96.2 %). Phylogenetic analysis based on the 16S rRNA gene sequences showed that the strain formed a clear phylogenetic lineage with the genus Actinotalea. The major fatty acids were identified as C15 : 0 anteiso, C16 : 0, C16 : 0 N alcohol, C15 : 1 anteiso A and C15 : 0 iso. The major cellular polar lipids were diphosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol and glycolipid. The peptidoglycan type was A4β containing l-Orn-d-Glu. The whole-cell-wall sugars were glucose and ribose. The respiratory quinone was identified as menaquinone MK-10(H4), and the genomic DNA G+C content was determined to be 74.8 mol %. Based on evidence from this polyphasic study, it is proposed that strain EBR-4-2T should be designated as representing a novel species named Actinotalea caeni sp. nov. The type stain is EBR-4-2T (=KCTC 33604T=JCM 30447T).

Mandibular stability using sliding or conventional four-hole plates for fixation after bilateral sagittal split ramus osteotomy for mandibular setback

Our aim was to compare the postoperative stability of the mandible when two different fixation methods had been used after bilateral sagittal split ramus osteotomy (BSSRO) for mandibular setback. The study included 23 patients who had two-jaw BSSRO mandibular setback at the Department of Oromaxillofacial Surgery, Korea University Guro Hospital, between January 2011 and June 2014. The first group (four-hole (control) group, n=13) comprised patients whose bony segments were fixed with conventional four-hole plates, and the second (sliding plate (experimental) group, n=10) included patients whose bone segments were fixed with sliding plates. Lateral cephalograms were taken and analysed at three time points: preoperatively (T1), and one week (T2), and 1year (T3) postoperatively. The Mann-Whitney U test was used to compare the postoperative stability of the mandible in each group. There were no significant differences between the two groups in changes in the horizontal and vertical positions of point B and pogonion postoperatively, nor were there any significant differences between them in ramal inclination and inclination of the SN plane with point B at the given time points (p=>0.05 in surgical changes in the mandible immediately after surgery and 0.397, 0.616, 0.082, 0.951, 0.901, 0.476 in postoperative changes in the mandible 1 week to 1 year after surgery). Like the conventional four-hole plate, the sliding plate can also be used to achieve stability in the fixation of mandibular bone segments after BSSRO.

Investigation on quench initiation and propagation characteristics of GdBCO coil co-wound with a stainless steel tape as turn-to-turn metallic insulation

This paper investigates the quench initiation and propagation characteristics of a metallic insulation (MI) coil by conducting thermal quench tests for a GdBCO single-pancake coil co-wound with a stainless steel tape as the turn-to-turn MI. The test results confirmed that the MI coil exhibited superior thermal and electrical stabilities compared to the conventional coils co-wound with organic insulation material because the operating current could flow along the radial direction due to the existence of a turn-to-turn contact when a local hot spot was generated. The results of the quench test at a heater current (I_h) of 12, 13, and 14 A indicate that the MI coil possesses a self-protecting characteristic resulting from the "current bypass" through the turn-to-turn contact. However, the test coil was not self-protecting at I_h = 15 A because the Joule heat energy generated by the radial current flow was not completely dissipated due to the characteristic resistance of the metallic insulation tape and the non-superconducting materials, including the substrate, stabilizer, and buffer layers within the high-temperature superconductor (HTS) tape. Even though the MI coil possesses superior thermal and electrical stability relative to those of conventional HTS coils co-wound with an organic material as turn-to-turn insulation, it is essential to consider the critical role of the Joule heat energy resulting from the operating current and stored magnetic energy as well as the characteristic resistances in order to further develop self-protective 2G HTS magnets.

Pusillimonas caeni sp. nov., isolated from a sludge sample of a biofilm reactor

A polyphasic taxonomic study was carried out on strain EBR-8-1^T isolated from a biofilm reactor in Korea. The cells of the strain were Gram-stain negative, non-spore-forming, non-motile, and short rod-shaped. Comparative 16S rRNA gene sequence studies showed a clear affiliation of this strain with Betaproteobacteria, which showed high pairwise sequence similarities with Pusillimonas noertemannii BN9^T (99.1 %), Pusillimonas soli MJ07^T (97.3 %), Pusillimonas ginsengisoli DCY25^T (97.2 %), and Pusillimonas harenae B201^T (96.8 %). The phylogenetic analysis based on 16S rRNA gene sequences showed that the strain formed a clear phylogenetic lineage within the genus Pusillimonas. The major fatty acids were identified as C_16:0, C_17:0 cyclo and C_19:0 cyclo ω8c. The major cellular polar lipids were identified as phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and an unidentified aminolipid. The respiratory quinone was identified as Q-8 and the genomic DNA G+C content was determined to be 63.3 mol%. On the basis of polyphasic evidence, it is proposed that strain EBR-8-1^T should be placed in a new species, Pusillimonas caeni sp. nov. The type stain is EBR-8-1^T (=KCTC 42353^T = JCM 30463^T).