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Wan-Taek Im

Publications and source records attributed to Wan-Taek Im.

35 records · Page 2Linked to original sources
PubMed2005

Pseudoxanthomonas koreensis sp. nov. and Pseudoxanthomonas daejeonensis sp. nov.

Gram-negative, non-spore-forming, rod-shaped bacteria, T7-09(T) and TR6-08(T), were isolated from soil from a ginseng field in South Korea and characterized to determine their taxonomic position. 16S rRNA gene sequence analysis showed that the two isolates shared 99.5 % sequence similarity. Strains T7-09(T) and TR6-08(T) were shown to belong to the Proteobacteria and showed the highest levels of sequence similarity to Pseudoxanthomonas broegbernensis DSM 12573(T) (98.1 %), Pseudoxanthomonas mexicana AMX 26B(T) (97.4-97.5 %), Pseudoxanthomonas japonensis 12-3(T) (96.5-96.6 %), Pseudoxanthomonas taiwanensis ATCC BAA-404(T) (95.7 %) and Xanthomonas campestris ATCC 33913(T) (96.3-96.5 %). The sequence similarity values with respect to any species with validly published names in related genera were less than 96.5 %. The detection of a quinone system with Q-8 as the predominant compound and a fatty acid profile with C(15 : 0) iso as the predominant acid supported the assignment of the novel isolates to the order 'Xanthomonadales'. The two isolates could be distinguished from the established species of the genus Pseudoxanthomonas by the presence of quantitative unsaturated fatty acid C(17 : 1) iso omega9c and by their unique biochemical profiles. The results of DNA-DNA hybridization clearly demonstrated that T7-09(T) and TR6-08(T) represent separate species. On the basis of these data, it is proposed that T7-09(T) (=KCTC 12208(T)=IAM 15116(T)) and TR6-08(T) (=KCTC 12207(T)=IAM 15115(T)) be classified as the type strains of two novel Pseudoxanthomonas species, for which the names Pseudoxanthomonas koreensis sp. nov. and Pseudoxanthomonas daejeonensis sp. nov., respectively, are proposed.

Bacterial Typing Techniques↗
PubMed2005

Lysobacter concretionis sp. nov., isolated from anaerobic granules in an upflow anaerobic sludge blanket reactor.

The taxonomic positions of Lysobacter species with validly published names and a novel strain Ko07(T), which was newly isolated from an upflow anaerobic sludge blanket reactor treating wastewater from a brewery, were (re)estimated on the basis of results obtained by using a polyphasic taxonomy approach. Phylogenetic inference based on 16S rRNA gene sequences showed that strain Ko07(T) and all Lysobacter species with validly published names clustered together in a phylogenetic branch within the class 'Gammaproteobacteria'. The sequence similarity of strain Ko07(T) to the type strains of established Lysobacter species was in the range 94.9-96.7 %. Ubiquinone Q-8 and branched fatty acids, C(11 : 0) iso, C(15 : 0) iso, C(16 : 0) iso, iso C(17 : 1)omega9c and C(11 : 0) iso 3OH, predominantly appeared in strain Ko07(T) as well as in all type strains of the recognized Lysobacter species. The DNA-DNA hybridization values of strain Ko07(T) with those of recognized Lysobacter species were estimated to be 2-20 %. Despite sharing common taxonomic features in important phenotypic characteristics, such as gliding movement, long-rod shape and proteolytic activity, strain Ko07(T) could be distinguished from the Lysobacter species with validly published names by its low DNA-DNA hybridization value, a comparatively low DNA G + C content (63.8 mol%), substrate utilization and some physiochemical characteristics. On the basis of the results obtained in this study, it is proposed that strain Ko07(T) should be classified as representing a novel member of the genus Lysobacter, for which the name Lysobacter concretionis sp. nov. is proposed. The type strain is Ko07(T) (=KCTC 12205(T) = DSM 16239(T)).

Bacterial Typing Techniques↗
PubMed2005

Flavobacterium granuli sp. nov., isolated from granules used in a wastewater treatment plant.

A Gram-negative, rod-shaped, non-spore-forming bacterium (designated strain Kw05(T)) was isolated from granules used in the wastewater treatment plant of a beer-brewing factory in Kwang-Ju, Republic of Korea. On the basis of 16S rRNA gene sequence similarity, strain Kw05(T) was shown to belong to the family Flavobacteriaceae, and was most closely related to Flavobacterium limicola (96.6 %), Flavobacterium hibernum (96.3 %), Flavobacterium hydatis (96.1 %) and Flavobacterium xinjiangense (96.1 %). The G+C content of the genomic DNA of strain Kw05(T) was 36.2 mol%, within the range of 32-37 mol% for the genus Flavobacterium. Chemotaxonomic data (major menaquinone MK-6; major fatty acids iso-C(15 : 0), iso-C(17 : 0) 3-OH, iso-C(15 : 0) 3-OH and iso-C(17 : 1)omega9c) supported the classification of strain Kw05(T) within the genus Flavobacterium. Kw05(T) therefore represents a novel species, for which the name Flavobacterium granuli sp. nov. is proposed. The type strain is Kw05(T) (=KCTC 12201(T)=IAM 15099(T)).

Bacterial Adhesion↗
PubMed2005

Paracoccus koreensis sp. nov., isolated from anaerobic granules in an upflow anaerobic sludge blanket (UASB) reactor.

A Gram-negative, short rod- to coccus-shaped, non-spore-forming bacterium (Ch05(T)) was isolated from granules in an upflow anaerobic sludge blanket (UASB) reactor. On the basis of 16S rRNA gene sequence similarity, strain Ch05(T) was shown to belong to the subclass alpha-Proteobacteria, being related to Paracoccus solventivorans (97.5%), Paracoccus alkenifer (96.9%) and Paracoccus kocurii (96.4%). The phylogenetic distance from Paracoccus species with validly published names was always less than 96%. Physiological and chemotaxonomic data (major ubiquinone, Q-10; major fatty acids, C(18:1) and C(18:0)) supported the affiliation of strain Ch05(T) to the genus Paracoccus. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain Ch05(T) from the 17 Paracoccus species with validly published names. Ch05(T) therefore represents a novel species, for which the name Paracoccus koreensis sp. nov. is proposed. The type strain is Ch05(T) (=KCTC 12238(T)=IAM 15216(T)).

Anaerobiosis↗
PubMed2005

Rhizobium daejeonense sp. nov. isolated from a cyanide treatment bioreactor.

A polyphasic study was carried out to determine the taxonomic position of two aerobic, cyanide-degrading bacterial strains, designated L61T and L22, which had been isolated from a bioreactor for the treatment of nickel-complexed cyanide. The two isolates exhibited almost identical taxonomic characteristics. Phylogenetic analysis inferred from comparative 16S rRNA gene sequences indicated that the isolates fall in a sublineage of the genus Rhizobium comprising the type strains of Rhizobium giardinii, Rhizobium radiobacter, Rhizobium rubi, Rhizobium larrymoorei, Rhizobium vitis, Rhizobium undicola, Rhizobium loessense, Rhizobium galegae and Rhizobium huautlense. Cells of the two isolates are Gram-negative, aerobic, motile and non-spore-forming rods (0.6-0.7x1.1-1.3 microm), with peritrichous flagella. The DNA G+C content is 60.1-60.9 mol%. Cellular fatty acids are C(16 : 0) (2.2-3.3 %), C(18 : 0) (2.1-3.2 %), C(19 : 0) cyclo omega8c (9.9-16.8 %), C(20 : 3)omega6,9,12c (2.7-3.3 %), summed feature 3 (7.2-7.7 %) and summed feature 7 (67.8-73.7 %). The strains formed nodules on a legume plant, Medicago sativa. A nifH gene encoding denitrogenase reductase, the key component of the nitrogenase enzyme complex, was detected in L61T by PCR amplification by using a nifH-specific primer system. Strains L61T and L22 were distinguished from the type strains of recognized Rhizobium species in the same sublineage based on low DNA-DNA hybridization values (2-4 %) and/or a 16S rRNA gene sequence similarity value of less than 96 %. Moreover, some phenotypic properties with respect to substrate utilization as a carbon or nitrogen source, antibiotic resistance and growth conditions could be used to discriminate L61T and L22 from Rhizobium species in the same sublineage. Based on the results obtained in this study, L61T and L22 are considered to be representatives of a novel species of Rhizobium, for which the name Rhizobium daejeonense sp. nov. is proposed. The type strain is L61T (=KCTC 12121T=IAM 15042T=CCBAU 10050T).

Bioreactors↗
PubMed2005

Phenylobacterium koreense sp. nov., isolated from South Korea.

A Gram-negative, aerobic, rod-shaped, non-spore-forming bacterium, Slu-01(T), was isolated from activated sludge from a wastewater treatment plant in Daejeon, South Korea. After 3 days on R2A medium, strain Slu-01(T) developed colourless colonies (0.7-1.2 mm). The non-motile rods (0.7-1.0 x 1.0-2.0 microm) were slightly curved and occurred singly and in pairs. No filamentous cells were found. On the basis of 16S rRNA gene sequence similarity, strain Slu-01(T) was shown to belong to the family Caulobacteraceae and was most closely related to Phenylobacterium immobile (96.6%) and Phenylobacterium lituiforme (96.5%). The genomic DNA G+C content of strain Slu-01(T) was 68.1 mol%, within the range of 67.3-68.4 mol% for the genus Phenylobacterium. Chemotaxonomic data (major ubiquinone, Q-10; major fatty acids C(18:1)omega7c, C(16:0), C(15:0) and C(17:0)) and 16S rRNA gene sequence analysis supported the affiliation of strain Slu-01(T) to the genus Phenylobacterium. However, DNA-DNA hybridization data and phenotypic properties showed that strain Slu-01(T) could be distinguished from the two other Phenylobacterium species with validly published names. Thus, it is suggested that strain Slu-01(T) represents a novel species of the genus Phenylobacterium, for which the name Phenylobacterium koreense is proposed. The type strain is Slu-01(T) (=KCTC 12206(T)=IAM 15119(T)).

Bacterial Typing Techniques↗
PubMed2005

Dyella koreensis sp. nov., a beta-glucosidase-producing bacterium.

A bacterial strain (designated BB4(T)), which has beta-glucosidase activity, was isolated from soil around the roots of bamboo plants. Cells were Gram-negative, aerobic, non-motile and straight-rod-shaped. Phylogenetic analysis of 16S rRNA gene sequences revealed a clear affiliation with members of the family 'Xanthomonadaceae'. The 16S rRNA gene sequence of strain BB4(T) showed the following sequence similarities: 97.7% to Dyella japonica XD53(T), 97.1% to Frateuria aurantia LMG 1558(T), 96.2% to Fulvimonas soli LMG 19981(T), 94.3% to Rhodanobacter lindaniclasticus RP5575(T) and <90% to other members of the 'Gammaproteobacteria'. The G+C content of the genomic DNA was 63.8 mol%. The major fatty acids were branched forms, especially large proportions of iso-C(15:0), iso-C(17:0) and iso-C(17:1)omega9c, similar to the profile of the genus Dyella. The results of DNA-DNA hybridization with D. japonica XD53(T) and Frateuria aurantia LMG 1558(T), in combination with phenotypic characteristics and 16S rRNA gene sequence analysis, demonstrated that strain BB4(T) should be classified as a novel Dyella species. The name Dyella koreensis sp. nov. is proposed, with strain BB4(T) (=KCTC 12359(T)=NBRC 100831(T)) as the type strain.

Bacterial Typing Techniques↗
PubMed2005

Cellulomonas terrae sp. nov., a cellulolytic and xylanolytic bacterium isolated from soil.

A bacterial strain (DB5(T)), with polysaccharide-degrading activities, was isolated from garden soil in Daejeon, Republic of Korea. The cells were Gram-positive, aerobic or facultatively anaerobic, non-motile straight rods. Phylogenetic analysis based on 16S rRNA gene sequences showed that this strain belongs to the genus Cellulomonas and that it is most closely related to Cellulomonas xylanilytica LMG 21723(T) and Cellulomonas humilata ATCC 25174(T) (98.0 and 97.9% similarity, respectively). Chemotaxonomic data also supported the classification of strain DB5(T) in the genus Cellulomonas, i.e. L-ornithine as the cell-wall diamino acid, anteiso-C(15:0) and iso-C(15:0) as the major fatty acids, MK-9(H(4)) as the predominant menaquinone and the presence of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol mannosides in the polar lipid profile. The results of DNA-DNA hybridization in combination with chemotaxonomic and physiological data demonstrated that strain DB5(T) (=KCTC 19081(T)=NBRC 100819(T)) should be classified as the type strain of a novel species within the genus Cellulomonas, for which the name Cellulomonas terrae sp. nov. is proposed.

Bacterial Typing Techniques↗
PubMed2005

Silvimonas terrae gen. nov., sp. nov., a novel chitin-degrading facultative anaerobe belonging to the 'Betaproteobacteria'.

A taxonomic study was carried out on a bacterial strain, designated KM-45T, isolated from forest soil collected near Daejeon, South Korea. Comparative 16S rRNA gene sequence analysis indicated a clear affiliation of this bacterium to the 'Betaproteobacteria' and that it was related most closely to Chitinibacter tainanensis BCRC 17254T, Formivibrio citricus DSM 6150T and Iodobacter fluviatilis ATCC 33051T (92.4, 91.2 and 88.9 % 16S rRNA gene sequence similarity, respectively). Cells were Gram-negative, facultatively anaerobic, motile and rod-shaped. The strain grew well on R2A medium and utilized a broad spectrum of carbon sources. The G+C content of the genomic DNA was 58 mol% and the predominant ubiquinone was Q-8. Major fatty acids were C(16 : 0), C(16 : 1)omega7c/iso-C(15 : 0) 2-OH, C(18 : 1)omega7c/omega9t/omega12t and C(17 : 0) cyclo. On the basis of the evidence presented, it is proposed that strain KM-45T should be placed in a novel genus and species, for which the name Silvimonas terrae gen. nov., sp. nov. is proposed. The type strain is KM-45T (=KCTC 12358T=NBRC 100961T).

Bacteria, Anaerobic↗
PubMed2005

Sphingopyxis granuli sp. nov., a beta-glucosidase-producing bacterium in the family Sphingomonadaceae in alpha-4 subclass of the Proteobacteria.

Strain Kw07T, a Gram-negative, non-spore-forming, rod-shaped bacterium, was isolated from granules in an Up-flow Anaerobic Sludge Blanket (UASB) bioreactor used in the treatment of brewery wastewater. 16S rRNA gene sequence analysis revealed that strain Kw07T belongs to the alpha-4 subclass of the Proteobacteria, and the highest degree of sequence similarity was determined to be to Sphingopyxis macrogoltabida IFO 15033T(97.8%). Chemotaxonomic data revealed that strain Kw07T possesses a quinone system with the predominant compound Q-10, the predominant fatty acid C18:1 omega7c, and sphingolipids, all of which corroborated our assignment of the strain to the Sphingopyxis genus. The results of DNA-DNA hybridization and physiological and biochemical tests clearly demonstrated that strain Kw07T represents a distinct species. Based on these data, Kw07T (=KCTC 12209T=NBRC 100800T) should be classified as the type strain for a novel Sphingopyxis species, for which the name Sphingopyxis granuli sp. nov. has been proposed.

Base Composition↗
PubMed2004

Development of a plate technique for screening of polysaccharide-degrading microorganisms by using a mixture of insoluble chromogenic substrates.

A plate assay based on the visible solubilization of small substrate particles and the formation of haloes on Petri dishes, containing a mixture of different dye-labelled polysaccharides as substrates, provides a specific, reliable and rapid simultaneous detection of corresponding polysaccharide-degrading microorganisms. It has potential for increasing the efficacy of screening of microorganisms, utilizing different polysaccharides, in large numbers of natural samples. Diversely colored insoluble forms of amylose, xylan and hydroxyethyl-cellulose (HE-cellulose) were prepared as chromogenic substrates by using the cross-linking reagent 1,4-butanediol diglycidyl ether and the dyes Brilliant Red 3B-A, Cibacron Blue 3GA and Reactive Orange 14. Using the method, the bacteria with amylase or xylanase or cellulase or a combination of these activities were screened from soil and sludge samples, selected and identified according to 16S rDNA sequencing.

Amylose↗
PubMed2004

Herbaspirillum chlorophenolicum sp. nov., a 4-chlorophenol-degrading bacterium.

A 4-chlorophenol-degrading bacterial strain, formerly designated as a strain of Comamonas testosteroni, was reclassified as a member of the genus Herbaspirillum based on its phenotypic and chemotaxonomic characteristics, as well as phylogenetic analysis using 16S rDNA sequences. Phylogenetic inference based on 16S rDNA sequences showed that strain CPW301(T) clusters in a phylogenetic branch that contains Herbaspirillum species. 16S rDNA sequence similarity of strain CPW301(T) to species of the genus Herbaspirillum with validly published names is in the range 98.7-98.9 %. Despite the considerably high 16S rDNA sequence similarity, strain CPW301(T) could be distinguished clearly from type strains of Herbaspirillum species with validly published names by DNA-DNA relatedness values, which were <15.7 %. The genomic DNA G+C content of strain CPW301(T) is 61.3 mol%. The predominant ubiquinone is Q-8 and the major cellular fatty acids are C(16 : 0) and cyclo-C(17 : 0). The strain does not fix nitrogen and is not plant-associated. It is an aerobic rod with one unipolar flagellum. On the basis of these characteristics, a novel Herbaspirillum species, Herbaspirillum chlorophenolicum sp. nov., is proposed. The type strain of the novel species is strain CPW301(T) (=KCTC 12096(T)=IAM 15024(T)).

Base Composition↗
PubMed2004

Kaistella koreensis gen. nov., sp. nov., a novel member of the Chryseobacterium-Bergeyella-Riemerella branch.

Gram-negative, non-spore-forming, rod-shaped, yellow-pigmented bacteria isolated from a freshwater stream in Korea were investigated to determine their taxonomic position. Complete 16S rRNA gene sequence analysis indicated that the organisms should be placed in the Chryseobacterium-Bergeyella-Riemerella branch in the family Flavobacteriaceae. Phylogenetically, the strains were most closely related to Chryseobacterium balustinum ATCC 33487(T) and Chryseobacterium scophthalmum LMG 13028(T) (94.3 and 94.1 % 16S rRNA gene sequence similarity, respectively) and they clustered on a separate well-supported branch. The strains contained menaquinone MK-6 as the predominant respiratory quinone and showed higher G+C contents (41.7 mol%) than other species in the Chryseobacterium-Bergeyella-Riemerella branch and i-C(15 : 0) as a major fatty acid (47-52 %). The phylogenetic distances from any species with validly published names and their phenotypic properties confirmed that the strains constitute a separate species in a new genus, for which the name Kaistella koreensis gen. nov., sp. nov. is proposed (type strain Chj707(T)=KCTC 12107(T)=IAM 15050(T)).

Bacterial Typing Techniques↗
PubMed2004

Rhodanobacter fulvus sp. nov., a beta-galactosidase-producing gammaproteobacterium.

A taxonomic study was carried out on a bacterial strain designated as Jip2T isolated from a soil sample mixed with rotten rice straw. It was a Gram-negative, aerobic, motile, and rod-shaped bacterium. It grew well on nutrient agar medium and utilized a fairly narrow spectrum of carbon source. The G+C content of the genomic DNA was 65.3 mol%. The major ubiquinone was Q-8. The major fatty acids were branched fatty acids, especially large amounts of iso C15:0 and iso C17:1 w9c were detected in the cells grown on TSA agar for 24 h. Comparative 16S rDNA study showed a clear affiliation of this bacterium to the genus Rhodanobacter. The 16S rDNA sequence of strain Jip2T showed 96.4% sequence similarity to that of Rhodanobacter lindaniclasticus RP5575T. On the basis of phenotypic characteristics and 16S rDNA sequence analysis, strain Jip2T is clearly distinct from Rhodanobacter lindaniclasticus. We propose the name Rhodanobacter fulvus sp. nov. for strain Jip2T (=IAM 15025T=KCTC 12098T).

Base Composition↗
PubMed2004

Kaistia adipata gen. nov., sp. nov., a novel alpha-proteobacterium.

A taxonomic study was carried out on Chj404T, a bacterial strain isolated from a soil sample collected in an industrial stream near the Chung-Ju industrial complex in Korea. The strain was a gram-negative, aerobic, short rod to coccus-shaped bacterium. It grew well on nutrient agar medium and utilized a broad spectrum of carbon sources. The G+C content of the DNA was 67.4 mol% and the major composition of ubiquinone was Q-10. The major fatty acid was C18:1. Comparative 16S rDNA studies showed a clear affiliation of this bacterium to alpha-Proteobacteria. Comparison of phylogenetic data indicated that it was most closely related to Prosthecomicrobium pneumaticum (92.7% similarity in 16S rDNA sequence). Since strain Chj404 is clearly distinct from closely related species, we propose the name Kaistia adipata gen. nov., sp. nov. for this strain Chj404T (=IAM 15023T=KCTC 12095T).

Alphaproteobacteria↗
PubMed2003

Isolation and characterization of bacteria capable of degrading phenol and reducing nitrate under low-oxygen conditions.

Nitrate-reducing bacteria capable of degrading phenol were isolated from natural and contaminated environments under low-oxygen conditions with nitrate-containing media, using phenol as a sole carbon and energy source. A total of 27 bacteria able to degrade phenol and reduce nitrate under low-oxygen conditions were isolated from all of the inoculum samples, regardless of previous phenol contamination. For all of these bacteria, oxygen was an essential requirement for phenol degradation. Nitrate reduction by 19 of the strains was insensitive to 10 mM sodium azide, and these strains were placed into the alpha- and beta-subclasses of Proteobacteria and two were Gram-positive bacteria. To date, the order of Rhizobiales has hardly been reported to have an ability to degrade aromatic compounds. Interestingly, our study showed that all isolates that were placed into the alpha-subclass of Proteobacteria are in the order of Rhizobiales. Furthermore, the genus Agrobacterium was isolated from most inoculum samples and one genus of Gram-positive bacteria, Staphylococcus, was also isolated. In the case of the remaining eight strains, nitrate reduction was inhibited by 10 mM sodium azide. Of these strains, seven were placed into the gamma-subclass of Proteobacteria.

Alphaproteobacteria↗