Search

Two Gram-reaction-negative, rod-shaped, gliding, yellow-pigmented bacterial strains, designated ZLD-17(T) and ZLD-29(T), were isolated from arid soil samples collected from Xinjiang Province, north-west China, and subjected to analysis using a polyphasic taxonomic approach. Both novel strains required 1.0-2.0 % (w/v) sea salts for optimal growth. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these two strains belong to the genus Lysobacter within the class Gammaproteobacteria. Strain ZLD-17(T) showed highest 16S rRNA gene sequence similarities to Lysobacter capsici KCTC 22007(T) (96.9 %), Lysobacter spongiicola DSM 21749(T) (96.8 %) and Lysobacter koreensis KCTC 12204(T) (96.8 %), whereas strain ZLD-29(T) showed highest sequence similarities to Lysobacter niastensis DSM 18481(T) (96.0 %) and Lysobacter enzymogenes DSM 2043(T) (95.9 %). 16S rRNA gene sequence similarity between ZLD-17(T) and ZLD-29(T) was 96.1 %. The DNA G+C contents of strains ZLD-17(T) and ZLD-29(T) were 67.9 and 68.2 mol%, respectively. The major cellular fatty acids of both strains were summed feature 3 (iso-C₁₅:₀ 2-OH and/or C₁₆:₁ω7c), iso-C₁₇:₁ω9c, iso-C₁₆:₀, C₁₆:₀ and iso-C₁₁:₀ 3-OH; their predominant isoprenoid quinone was Q-8 and their major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Based on their phenotypic characteristics, phylogenetic position as determined by 16S rRNA gene sequence analysis and chemotaxonomic data, strains ZLD-17(T) ( = CCTCC AB 207174(T)  = KCTC 23076(T)) and ZLD-29(T) ( = CCTCC AB 207175(T) = KCTC 23077(T)) represent two novel species of the genus Lysobacter, for which the names Lysobacter korlensis sp. nov. and Lysobacter bugurensis sp. nov. are proposed, respectively.

A Gram-negative, non-motile, rod-shaped bacterial strain, DS-58(T), was isolated from a soil sample from Dokdo, an island of Korea, and its taxonomic position was investigated. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain DS-58(T) fell within the family Xanthomonadaceae. The isolate showed 96.9 % 16S rRNA gene sequence similarity with its closest phylogenetic neighbour, Lysobacter niastensis GH41-7(T), and 93.4-95.7 % 16S rRNA gene sequence similarity with other members of the genus Lysobacter. Strain DS-58(T) contained Q-8 as the predominant ubiquinone and iso-C(16 : 0), iso-C(15 : 0) and iso-C(17 : 1)ω9c as the major fatty acids. The DNA G+C content was 68.1 mol%. Strain DS-58(T) could be distinguished phenotypically from type strains of closely related species of the genus Lysobacter and phylogenetically from all members of the genus Lysobacter. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain DS-58(T) is considered to represent a novel species of the genus Lysobacter, for which the name Lysobacter dokdonensis sp. nov. is proposed. The type strain is DS-58(T) ( = KCTC 12822(T)  = DSM 17958(T)).

An aerobic, Gram-negative bacterial strain, designated CTN-1(T), capable of degrading chlorothalonil was isolated from a long-term chlorothalonil-contaminated soil in China, and was subjected to a polyphasic taxonomic investigation. Strain CTN-1(T) grew at 15-37 °C (optimum 28-30 °C) and at pH 6.0-9.0 (optimum pH 7.0-7.5). The G+C content of the total DNA was 67.1 mol%. Based on 16S rRNA gene sequence analysis, strain CTN-1(T) was related most closely to Lysobacter daejeonensis DSM 17634(T) (97.1  % similarity), L. soli DCY21(T) (95.7  %), L. concretionis Ko07(T) (95.5  %), L. gummosus LMG 8763(T) (95.3 %) and L. niastensis DSM 18481(T) (95.2  %). The novel strain showed less than 95.0 % 16S rRNA gene sequence similarity to the type strains of other Lysobacter species. The major cellular fatty acids of strain CNT-1(T) were iso-C₁₆:₀ (23.0  %), iso-C₁₅:₀ (21.4  %) and iso-C₁₇:₁ω9c (15.3  %). The major isoprenoid quinone was Q-8 (99 %), and the major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. These chemotaxonomic data supported the affiliation of strain CTN-1(T) to the genus Lysobacter. Levels of DNA-DNA relatedness between strain CTN-1(T) and L. daejeonensis DSM 17634(T) were 34.6-36.1  %. Phylogenetic analysis based on 16S rRNA gene sequences, DNA-DNA hybridization data and biochemical and physiological characteristics strongly supported the genotypic and phenotypic differentiation of strain CTN-1(T) from recognized species of the genus Lysobacter. Strain CTN-1(T) is therefore considered to represent a novel species of the genus Lysobacter, for which the name Lysobacter ruishenii sp. nov. is proposed. The type strain is CTN-1(T) (=DSM 22393(T) =CGMCC 1.10136(T)).

A yellow-pigmented bacterial strain, designated RCML-52(T), was isolated from an abandoned gold mine in the desert in Xinjiang, China. Strain RCML-52(T) was Gram-negative, aerobic and non-motile. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain RCML-52(T) was affiliated with the genus Lysobacter. Strain RCML-52(T) exhibited <95.6 % 16S rRNA gene sequence similarity to the type strains of all species of the genus Lysobacter. The major fatty acids were iso-C(16 : 0) (27.6 %), iso-C(15 : 0) (19.1 %), iso-C(17 : 1)ω9c (16.4 %), iso-C(11 : 0) 3-OH (6.5 %) and iso-C(11 : 0) (5.3 %). The DNA G+C content was 69.7 mol%. The major isoprenoid quinone was Q-8. On the basis of phylogenetic, phenotypic and chemotaxonomic analysis, strain RCML-52(T) should be assigned to a novel species of the genus Lysobacter, for which the name Lysobacter xinjiangensis sp. nov. is proposed. The type strain is RCML-52(T) (=CCTCC AB 208194(T) =KCTC 22558(T)).

Strain DCY21(T), a Gram-negative, gliding and rod-shaped aerobic bacterium was isolated from soil of a ginseng field in the Republic of Korea and characterized using a polyphasic approach in order to determine its taxonomic position. Comparative 16S rRNA gene sequence analysis revealed that strain DCY21(T) clustered with the species of the genus Lysobacter. It was closely related to Lysobacter gummosus LMG 8763(T) (97.9 %), Lysobacter capsici YC5194(T) (97.6 %), Lysobacter antibioticus DSM 2044(T) (97.5 %), Lysobacter niastensis DSM 18481(T) (97.2 %) and Lysobacter enzymogenes DSM 2043(T) (96.9 %). The major cellular fatty acids of strain DCY21(T) were iso-C(15 : 0) (34.3 %), iso-C(17 : 1)omega9c (19.5 %) and iso-C(17 : 0) (17.2 %) and the major isoprenoid quinone was Q-8. The major polar lipids of strain DCY21(T) were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidyl-N-methylethanolamine. The G+C content of the total DNA was 65.4 mol%. The DNA-DNA relatedness values, and biochemical and physiological characteristics strongly supported the genotypic and phenotypic differentiation of strain DCY21(T) from species of the genus Lysobacter. Strain DCY21(T) therefore represents a novel species, for which the name Lysobacter soli sp. nov. is proposed. The type strain is DCY21(T) (=KCTC 22011(T) =LMG 24126(T)).

Four Gram-negative bacterial strains, recovered from clay soils cultivated with different crops in the Netherland, were subjected to a polyphasic taxonomic study in order to clarify their taxonomic status. Comparative analysis of the 16S rRNA gene sequences revealed that they belong to the genus Lysobacter and to be highly related to the type strains of L. antibioticus DSM 2044(T), L. gummosus DSM 6980(T), and L. capsici DSM 19286(T), displaying 99.1-99.3%, 99.2-99.6% and 99.4-100% sequence similarities, respectively, to these species. The results of DNA-DNA hybridization studies unambigiously indicated that the four strains belonged to the species L. capsici. Nevertheless, DNA fingerprinting and phenotypic characterization indicated that there was a considerable diversification and niche differentiation among the strains belonging to L. capsici. The newly identified L. capsici strains strongly inhibit Rhizoctonia solani AG2 and originate from Rhizoctonia-suppressive soils where also populations of L. antibioticus and L. gummosus were present. This is the first report of the presence of combined populations of closely related Lysobacter spp. within agricultural soils.

Aims: To develop a strain-specific TaqMan PCR method for detecting and quantifying the biocontrol strain Lysobacter enzymogenes 3.1T8., Methods and Results: A primer-probe combination was designed on the basis of a strain-specific sequence selected using REP-PCR (repetitive extragenic palindromic-polymerase chain reaction). The specificity of this combination was demonstrated by 14 other Lysobacter strains that did not react with the selected primer-probe combination. To quantify strain 3.1T8 in cucumber root samples, a calibration curve was prepared by spiking roots with a 10-fold dilution series of the strain. Detection of the biocontrol strain 3.1T8 with this method showed that the strain survived well for 22 days on root tips as well as on older cucumber roots. Survival was higher when the strain was inoculated to younger plants. In a cucumber production system with large volumes of substrate, strain 3.1T8 was detected in high numbers on cucumber roots 3 weeks after inoculation., Conclusions: The primer-probe combination developed was strain specific, because it did not react with other strains of the same species and genus. The TaqMan PCR method successfully quantified the inoculated biocontrol strain on cucumber roots grown in different cropping systems., Significance and Impact of the Study: The developed TaqMan PCR method is a strain-specific real-time detection method that can be used to assess the population dynamics of L. enzymogenes strain 3.1T8 for further optimization of its biocontrol efficacy.

The exploration of new source materials and the use of alternative isolation and identification methods have led to rapid expansion in the knowledge of diversity; in Lysobacter, 11 new species having been described since 2005, and in Stenotrophomonas with six new species since 2000. The new species of Lysobacter, isolated by dilution and direct plating on standard media, differ in several key phenotypic properties from those obtained by enrichment on complex polysaccharides in the original description of the genus. Revision of the definition of the genus will be required. Both culture-dependent and culture-independent methods to assess community structure, in a variety of host and nonhost environments, have established that some species of Lysobacter are a dominant component of the microflora, where previously their presence had not been suspected. Culture-independent studies have generally not added new information on the occurrence and distribution of Stenotrophomonas maltophilia and other members of the genus, which are readily isolated on standard media from source materials. Lysobacter enzymogenes and Sten. maltophilia produce similar antibiotics and share some enzyme activities which, subject to safety considerations, may make them attractive candidates for use in biological control of plant diseases and of nematodes.

The novel carbazole (CAR)-degrading bacterium Lysobacter sp. strain OC7 has been isolated from seawater and can also utilize naphthalene and phenanthrene as its sole carbon and energy source. The CAR-degradative gene cluster was isolated and encoded five complete open reading frames (ORFs) and two truncated ORFs. Among them, four ORFs showed 40-50% similarity with previously reported CAR-degradative genes. Ferredoxin (carAc) and ferredoxin reductase (carAd) genes, which are necessary for the CAR 1,9a-dioxygenase system, were not found in this car gene cluster. The car (OC7) gene transcripts were strongly detected when CAR was provided. However, these transcripts were also detected when naphthalene was provided. The resting cell reaction with Escherichia coli revealed that CarAa(OC7) can use CarAc and CarAd of Pseudomonas resinovorans CA10 as ferredoxin and ferredoxin reductase, respectively, and converted CAR to 2'-aminobiphenyl-2,3-diol. In 13 marine CAR-degrading isolates, only Caulobacter sp. strain OC6 hybridized with the car (OC7) gene cluster probe. This is the first report showing CAR-degradative genes from the genus Lysobacter.

A Gram-negative, aerobic, rod-shaped, non-spore-forming bacterial strain, designated Gsoil 068(T), was isolated from soil of a ginseng field in Pocheon Province (South Korea), and was characterized to determine its taxonomic position by using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain Gsoil 068(T) belonged to the family Xanthomonadaceae, class Gammaproteobacteria, and was related most closely to Lysobacter brunescens ATCC 29482(T) and Lysobacter gummosus ATCC 29489(T) (96.1 % sequence similarity). The G+C content of the genomic DNA of strain Gsoil 068(T) was 67.0 mol%. The detection of a quinone system with ubiquinone Q-8 as the predominant component and a fatty acid profile with iso-C(15 : 0), iso-C(17 : 1)omega9c, iso-C(17 : 0) and iso-C(11 : 0) 3-OH as the major components supported the affiliation of strain Gsoil 068(T) to the genus Lysobacter. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil 068(T) is considered to represent a novel species of the genus Lysobacter, for which the name Lysobacter panaciterrae sp. nov. is proposed. The type strain is Gsoil 068(T) (=KCTC 12601(T) =DSM 17927(T)).

The taxonomic position of a novel bacterial strain, YC6269(T), isolated from the rhizosphere of rice (Oryza sativa L.) managed under no-tillage practice in Jinju, South Korea, was studied using polyphasic approach. Cells of the strain were Gram-negative, rod-shaped and facultatively anaerobic. The novel strain grew at a temperature of 15-42 degrees C (optimum at 28 degrees C). Growth of the strain occurred between pH 5.5 and 11.0, with an optimum at pH 7.0-8.0. The G+C content of the total DNA was 67.4 mol%. The 16S rRNA gene sequence of the strain was most closely related to species of the genus Lysobacter, Lysobacter yangpyeongensis DSM 17635(T) (98.6 %), Lysobacter niabensis GH34-4(T) (97.2 %), Lysobacter enzymogenes DSM 2043(T) (96.9 %), Lysobacter daejeonensis DSM 17634(T) (96.3 %) and Lysobacter niastensis GH41-7(T) (96.2 %). The novel strain showed <96.0 % similarity with other species of the genus Lysobacter. Chemotaxonomic data (major quinone, Q-8; major polar lipids, phosphatidylethanolamine, phosphatidylglycerol and phosphatidyl-N-methylethanolamine, and major fatty acids, C(15 : 0) iso, C(16 : 0) iso, C(17 : 0) iso and C(17 : 1) iso omega9c) supported the affiliation of strain YC6269(T) to the genus Lysobacter. Phylogenetic analysis based on the 16S rRNA gene sequences, DNA-DNA hybridization data and biochemical and physiological characteristics strongly supported the genotypic and phenotypic differentiation of strain YC6269(T) from recognized species of the genus Lysobacter. Strain YC6269(T), therefore, represents a novel member of the genus Lysobacter, for which the name Lysobacter oryzae sp. nov. is proposed. The type strain is YC6269(T) (=KCTC 22249(T)=DSM 21044(T)).

A bacterial isolate, strain XM415(T), obtained from soil of Tibet in China was characterized using a polyphasic taxonomic approach. Strain XM415(T) was aerobic, Gram-negative, gliding, rod-shaped, oxidase-negative and catalase-positive. Strain XM415(T) showed the highest 16S rRNA gene sequence similarity with Lysobacter niastensis GH41-7(T) (96.0 %). Ubiquinone Q-8 and branched fatty acids, such as iso-C(16 : 0) (24.0 %), iso-C(15 : 0) (22.6 %), iso-C(17 : 1)omega9c (6.7 %), iso-C(14 : 0) (6.1 %) and iso-C(11 : 0) 3-OH (5.2 %), were predominant in strain XM415(T) as well as in all type strains of recognized Lysobacter species. The DNA G+C content of XM415(T) was 63.5 mol%. The genotypic and phenotypic data show that strain XM415(T) represents a novel species of the genus Lysobacter, for which the name Lysobacter ximonensis sp. nov. is proposed. The type strain is XM415(T) (=CCTCC AB 207091(T) =NRRL B-51263(T)).

A Gram-negative, aerobic, rod shaped, non-spore-forming bacterial strain, designated Dae08(T), was isolated from sediment of the stream near Daechung dam in South Korea, and was characterized in order to determine its taxonomic position, using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain Dae08(T) belongs to the family Xanthomonadaceae of the Gammaproteobacteria, and is related to Lysobacter brunescens ATCC 29482(T) (97.3%). The phylogenetic distances from any other species with validly published names within the genus Lysobacter were greater than 3.7%. The G+C contents of the genomic DNA of strain Dae08(T) was 69.3 mol%. The detection of a quinone system with Q-8 as the predominant compound and a fatty acid profile with iso-C(15:0), iso-C(17:1), omega9c, iso-C(17:0), iso-C(16:0), and iso-C(11:0) 3-OH as the major acids supported the affiliation of strain Dae08(T) to the genus Lysobacter. DNA-DNA relatedness between strain Dae08(T) and its phylogenetically closest neighbour was 28%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Dae08(T) (= KCTC 12600(T)) should be classified in the genus Lysobacter as the novel species, for which the name Lysobacter daecheongensis sp. nov. is proposed.

A Gram-negative, aerobic, rod-shaped, nonspore-forming bacterial strain, designated Gsoil 357T, was isolated from soil sample of a ginseng field in Pocheon Province (South Korea). The isolate contained Q-8 as the predominant ubiquinone and iso-C16:0, iso-C17:1 9c, and iso-C15:0 as the major fatty acids. The G+C content of the genomic DNA was 69.3mol%. A phylogenetic analysis based on 16S rRNA gene sequences revealed that strain Gsoil 357T was most closely related to Lysobacter gummosus (97.6%) and Lysobacter antibioticus (97.6%). However, the DNA-DNA relatedness value between strain Gsoil 357T and its phylogenetically closest neighbors was less than 17%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil 357T should be classified as representing a novel species in the genus Lysobacter, for which the name Lysobacter ginsengisoli sp. nov. is proposed. The type strain is Gsoil 357T (=KCTC 12602T=DSM 18420T).

The taxonomic position of a novel bacterial strain, YC5194(T), with antimicrobial activity, isolated from the rhizosphere of pepper in Jinju, South Korea, was studied using a polyphasic approach. Cells of the strain were Gram-negative, rod-shaped, facultative anaerobes. It grew at a temperature of 15-37 degrees C (optimum 28 degrees C). Growth of the strain occurred between pH 5.5 and 8.5, with an optimum of pH 7.0-7.5. The strain inhibited mycelial growth of Pythium ultimum, Colletotrichum gloeosporioides, Fusarium oxysporum, Botrytis cinerea, Rhizoctonia solani and Botryosphaeria dothidea and growth of Bacillus subtilis. The G+C content of the total DNA was 65.4 mol%. The 16S rRNA gene sequence of the strain was most closely related to species of the genus Lysobacter (<94.0 to >99.0 % sequence similarity). Chemotaxonomic data (major quinone, Q-8; major polar lipids, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidyl-N-methylethanolamine; major fatty acids, iso-C(15 : 0), summed feature 3, C(16 : 0), iso-C(17 : 1)omega9c and C(18 : 1)omega7c) supported the affiliation of strain YC5194(T) to the genus Lysobacter. Phylogenetic analysis based on 16S rRNA gene sequences, DNA-DNA hybridization data and biochemical and physiological characteristics strongly supported the genotypic and phenotypic differentiation of strain YC5194(T) from species of Lysobacter with validly published names. Strain YC5194(T) therefore represents a novel species, for which the name Lysobacter capsici sp. nov. is proposed. The type strain is YC5194(T) (=KCTC 22007(T) =DSM 19286(T)).

An aerobic, Gram-negative bacterium, strain KMM 329(T), was isolated from a deep-sea sponge specimen from the Philippine Sea and subjected to a polyphasic taxonomic investigation. Comparative 16S rRNA gene sequence analysis showed that strain KMM 329(T) clustered with the species of the genus Lysobacter. The highest level of 16S rRNA gene sequence similarity (97.0 %) was found with respect to Lysobacter concretionis KCTC 12205(T); lower values (96.4-95.2 %) were obtained with respect to the other recognized Lysobacter species. The value for DNA-DNA relatedness between strain KMM 329(T) and L. concretionis KCTC 12205(T) was 47 %. Branched fatty acids 16 : 0 iso, 15 : 0 iso, 11 : 0 iso 3-OH and 17 : 1 iso were found to be predominant. Strain KMM 329(T) had a DNA G+C content of 69.0 mol%. On the basis of the phenotypic, chemotaxonomic, DNA-DNA hybridization and phylogenetic data, strain KMM 329(T) represents a novel species of the genus Lysobacter, for which the name Lysobacter spongiicola sp. nov. is proposed. The type strain is KMM 329(T) (=NRIC 0728(T) =JCM 14760(T)).

Beneficial bacteria that live on salamander skins have the ability to inhibit pathogenic fungi. Our study aimed to identify the specific chemical agent(s) of this process and asked if any of the antifungal compounds known to operate in analogous plant-bacteria-fungi systems were present. Crude extracts of bacteria isolated from salamander skin were exposed to HPLC, UV-Vis, GC-MS, and HR-MS analyses. These investigations show that 2,4-diacetylphloroglucinol is produced by the bacteria isolate Lysobacter gummosus (AB161361), which was found on the red-backed salamander, Plethodon cinereus. Furthermore, exposure of the amphibian fungal pathogen, Batrachochytrium dendrobatidis (isolate JEL 215), to different concentrations of 2,4-diacetylphloroglucinol resulted in an IC50 value of 8.73 microM, comparable to crude extract concentrations. This study is the first to show that an epibiotic bacterium on an amphibian species produces a chemical that inhibits pathogenic fungi.

A bacterial isolate obtained from soil from a municipal landfill site in India was characterized using a polyphasic taxonomic approach. The colonies of the isolate were found to be yellow and highly mucoid. Comparative analysis of the 16S rRNA gene sequence showed that this isolate constitutes a distinct phyletic line within the genus Lysobacter, displaying >3 % sequence divergence with respect to recognized Lysobacter species. The generic assignment was confirmed by chemotaxonomic data, which revealed the presence of a fatty acid profile characteristic of members of the genus Lysobacter and consisting of saturated, unsaturated, straight-chain and branched-chain fatty acids as well as iso-C(11 : 0) 3-OH as hydroxylated fatty acid, and the presence of an ubiquinone with eight isoprene units (Q-8) as the predominant respiratory quinone. The genotypic and phenotypic data show that strain IMMIB APB-9(T) merits classification as representing a novel species of the genus Lysobacter, for which the name Lysobacter defluvii sp. nov. is proposed. The type strain is IMMIB APB-9(T) (=CCUG 53152(T)=DSM 18482(T)).