Sphingomonas corticis sp. nov., and Sphingobacterium corticibacterium sp. nov., from bark canker.

Two Gram-stain-negative, aerobic, non-motile bacterial strains, 36D10-4-7T and 30C10-4-7T, were isolated from bark canker tissue of Populus × euramericana, respectively. 16S rRNA gene sequence analysis revealed that strain 36D10-4-7T shows 98.0 % sequence similarity to Sphingomonas adhaesiva DSM 7418T, and strain 30C10-4-7T shows highest sequence similarity to Sphingobacterium arenae H-12T (95.6 %). Average nucleotide identity analysis indicates that strain 36D10-4-7T is a novel member different from recognized species in the genus Sphingomonas. The main fatty acids and respiratory quinone detected in strain 36D10-4-7T are C18 : 1 ω7c and/or C18 : 1 ω6c and Q-10, respectively. The polar lipids are diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, aminolipid, phosphatidylethanolamine, sphingoglycolipid, two uncharacterized phospholipids and two uncharacterized lipids. For strain 30C10-4-7T, the major fatty acids and menaquinone are iso-C15 : 0, C16 : 1 ω7c and/or C16 : 1 ω6c and iso-C17 : 0 3-OH and MK-7, respectively. The polar lipid profile includes phosphatidylethanolamine, phospholipids, two aminophospholipids and six unidentified lipids. Based on phenotypic and genotypic characteristics, these two strains represent two novel species within the genera Sphingomonas and Sphingobacterium. The name Sphingomonas corticis sp. nov. (type strain 36D10-4-7T=CFCC 13112T=KCTC 52799T) and Sphingobacterium corticibacterium sp. nov. (type strain 30C10-4-7T=CFCC 13069T=KCTC 52797T) are proposed.

Sphingomonas populi sp. nov., isolated from bark of Populus × euramericana.

One Gram-stain-negative, aerobic, motile bacterial strain, 3-7T, was isolated from symptomatic canker bark tissue of Populus × euramericana. 16S rRNA gene sequence data revealed that the novel isolate shared highest similarity with Sphingomonas panacis DCY99T (98.8 %), and <96.5 % sequence similarity with all other species with validly published names. Growth occurred between 15 and 37 °C and at pH 6.0-9.0, and optimal growth occurred at 30 °C and pH 7.0-8.0. Nitrogen was produced from nitrates. The strain was positive for acetoin production and activity of catalase, oxidase, ß-galactosidase, arginine dihydrolase and ß-glucosidase. The major fatty acids were C16 : 0, C18 : 1ω7c and/or C18 : 1ω6c. The polar lipids of the novel isolate included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, sphingoglycolipid, glycolipid, two uncharacterized phospholipids and two uncharacterized lipids. The respiratory quinones detected in isolate 3-7T were Q-10 (96.9 %) and Q-9 (3.1 %). The DNA G+C content was 65.1 mol%. Based on phenotypic and genotypic characteristics, the isolate represents a novel species within the genus Sphingomonas, for which the name Sphingomonas populi is proposed. The type strain is 3-7T (=CFCC 11561T=LMG 30138T).

Sphingobacterium corticibacter sp. nov., isolated from bark of Populus × euramericana.

One Gram-stain negative, aerobic, non-motile bacterial strain, 2c-3T, was isolated from symptomatic canker bark tissue of Populus × euramericana. It was studied by the genome sequence-derived average nucleotide identity (ANI), phylogenetic analysis based on 16S rRNA gene sequences and phenotypic characteristics. 16S rRNA gene data revealed that the novel isolate shares the greatest sequence similarity to Sphingobacterium populi 7Y-4T (97.0 %). The ANI values between the novel isolate and S. populi 7Y-4T was 81.19 %, lower than the proposed species boundary ANI cut-off (95-96 %). The major fatty acids are iso-C15 : 0, C16 : 1ω7c and iso-C17 : 0 3-OH. The polar lipids of the novel isolate included phosphatidylethanolamine, phospholipid, aminophospholipid and unknown lipids (L1-10). The menaquinone of the novel isolate was MK-7. The DNA G+C content was 41.96 mol %. Based on phenotypic and genotypic characteristics, the isolate represents a novel species within the genus Sphingobacterium, for which the name Sphingobacterium corticibacter is proposed. The type strain is 2c-3T (=CFCC 11898T=KCTC 52798T).

Sinorhodobacter populi sp. nov., isolated from the symptomatic bark tissue of Populus × euramericana canker.

We isolated five novel bacterial strains from symptomatic bark tissue of Populus × euramericana canker that were Gram-stain-negative, non-motile, aerobic oxidase-negative and catalase-positive. Growth occurred at 10-41 °C and at pH 5.0-7.0, with optimum growth at 30 °C and pH 7.0. Additionally, growth occurred in conditions of 0-5 % (w/v) salinity, but not above 7 % NaCl. The 16S rRNA gene sequences of the novel strains shared the highest similarity with Sinorhodobacter ferrireducens SgZ-3T (97.1 %). The average nucleotide identity values between the novel strains and two type strains (S.inorhodobacter ferrireducens CCTCC AB2012026T and 'Sinorhodobacter hungdaonensis' CGMCC 1.12963T) were 78.4-78.9 %, which were lower than the proposed species boundary cut-off (95-96 %). The main polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified lipid and phosphatidylcholine. The main respiratory quinone was Q-10, and major fatty acids were C18 : 1ω7c and/or C18 : 1ω6c. Based on data from a polyphasic taxonomy study, the novel strains represent a novel species of the genus Sinorhodobacter, for which the name Sinorhodobacter populi sp. nov. is proposed. The type strain is sk2b1T (=CFCC 14580T=KCTC 52802T).

Wohlfahrtiimonas populi sp. nov., isolated from symptomatic bark of a Populus × euramericana canker.

A Gram-stain-negative, facultatively anaerobic, motile, bacterial strain, 34C10-3-10T, was isolated from symptomatic bark tissue of a Populus ×euramericana canker. The isolate could grow between 10 and 37 °C, at pH 5 to 11, and in 0-3 % (w/v) NaCl. The strain was oxidase and catalase positive. The ubiquinone of strain 34C10-3-10T was Q-8. The polar lipid profile of strain 34C10-3-10T included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phospholipid, phosphatidylmonomethylethanolamine, phosphatidylserine; the major fatty acids were C18 : 1ω7c, C14 : 0 and C16 : 1ω7c/C16 : 1ω6c. The average nucleotide identity (ANI) values between strain 34C10-3-10T and the type strains of reference species Wohlfahrtiimonas chitiniclastica S5T and Wohlfahrtiimonas larvae KBL006T were lower than the proposed species boundary cut-off for ANI. The DNA G+C content was 37.1 mol%. Based on phenotypic and genotypic characteristics, strain 34C10-3-10T represents a novel species of genus Wohlfahrtiimonas; the name Wohlfahrtiimonas populi sp. nov. is proposed. The type strain is 34C10-3-10T (=CFCC 12747T=KCTC 52796T).

Sphingobacterium corticis sp. nov., isolated from bark of Populus × euramericana.

A Gram-stain negative, aerobic, non-motile bacterial strain, 23D10-4-9T, was isolated from symptomatic canker bark tissue of Populus × euramericana. The isolate grew between 4 and 35 °C, with optimal growth occurring at 25 °C. The species was positive for catalase and negative for oxidase activity. Nitrate was not reduced to nitrite. It showed activities toward ß-galactosidase and ß-glucosidase. Citrate was not utilized. Acid was produced from d-glucose. The major fatty acids were iso-C15 : 0, C16 : 1ω7c and iso-C17 : 0 3-OH. The main polar lipid profiles of the novel isolate included phosphatidylethanolamine, phospholipids and seven unknown lipids. The predominant menaquinone of the novel isolate was MK-7. The DNA G+C content was 40.6 mol%. 16S rRNA gene data revealed that the novel isolate shares the greatest sequence similarity with Sphingobacterium populi 7Y-4T (96.1 %). Based on phenotypic and genotypic characteristics, the isolate represents a novel species within the genus Sphingobacterium, for which the name Sphingobacteriumcorticis sp. nov. is proposed. The type strain is 23D10-4-9T (=CFCC 12640T=KCTC 42248T).

Corticicoccus populi gen. nov., sp. nov., a member of the family Staphylococcaceae, isolated from symptomatic bark of Populus × euramericana canker.

Two Gram-stain-positive, aerobic, non-motile, bacterial strains were isolated from symptomatic bark tissue of Populus × euramericana canker. The isolates were able to grow between 10 and 37 °C, at pH 6-10 and with 0-4 % (w/v) NaCl, with optimal growth at 28-30 °C, pH 7.0-8.0 and with 2 % (w/v) NaCl The strains were found to be oxidase and catalase positive. The menaquinone of strain 26D10-3-4T was MK-7 and the peptidoglycan type A3α based on l-Lys-Gly3-?Ala. The polar lipid profiles of strain 26D10-3-4T showed diphosphatidylglycerol, phosphatidylglycerol, two unidentified phospholipids and three unidentified glycolipids, and the major fatty acids found were anteiso-C15 : 0, iso-C15 : 0, iso-C17 : 0 and anteiso-C17 : 0. The DNA G+C content was 38.2 mol%. The two novel isolates shared the highest 16S rRNA gene sequence similarity with Salinicoccus qingdaonensis ZXM223T (95.0 %). Based on phenotypic and genotypic characteristics, these two strains represent a novel species of a new genus of the family Staphylococcaceae; the name Corticicoccus populi gen. nov., sp. nov. is proposed. The type strain of the type species is 26D10-3-4T (=CFCC 12725T=KCTC 33575T). An additional strain of the species is 9-4-1.