A taxonomic study was performed on a novel Gram-stain-positive, coccus-shaped, orange-pigmented motile bacterium, designated as strain L10.15T. The organism was isolated from a soil sample collected in Lagoon Island (close to Adelaide Island, western Antarctic Peninsula) using a quorum-quenching enrichment medium. Growth occurred at 4-30 °C, pH 6-11 and at moderately high salinity (0-15 %, w/v, NaCl), with optimal growth at 26 °C, at pH 7-8 and with 6 % (w/v) NaCl. 16S rRNA gene sequence analysis showed that strain L10.15T belonged to the genus Planococcus and was closely related to Planococcus halocryophilus Or1T (99.3 % similarity), Planococcus donghaensis JH1T (99.0 %), Planococcus antarcticus DSM 14505T (98.3 %), Planococcus plakortidis AS/ASP6 (II)T (97.6 %), Planococcus maritimus TF-9T (97.5 %), Planococcus salinarum ISL-6T (97.5 %) and Planococcus kocurii NCIMB 629T (97.5 %). However, the average nucleotide identity-MUMmer analysis showed low genomic relatedness values of 71.1-81.7 % to the type strains of these closely related species of the genus Planococcus. The principal fatty acids were anteiso-C15 : 0, C16 : 1ω7c and anteiso-C17 : 0, and the major menaquinones of strain L10.15T were MK-5 (48 %), MK-6 (6 %) and MK-7 (44 %). Polar lipid analysis revealed the presence of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and aminophospholipid. The DNA G+C content was 39.4 mol%. The phenotypic and genotypic data indicate that strain L10.15T represents a novel species of the genus Planococcus, for which the name Planococcus versutus sp. nov. is proposed. The type strain is L10.15T (=DSM 101994T=KACC 18918T).
Root exudates are chemical compounds that are released from living plant roots and provide significant energy, carbon, nitrogen and phosphorus sources for microbes inhabiting the rhizosphere. The exudates shape the microflora associated with the plant, as well as influences the plant health and productivity. Therefore, a better understanding of the trophic link that is established between the plant and the associated bacteria is necessary. In this study, a comprehensive survey on the utilization of grapevine and rootstock related organic acids were conducted on a vineyard soil isolate which is Pseudomonas mendocina strain S5.2. Phenotype microarray analysis has demonstrated that this strain can utilize several organic acids including lactic acid, succinic acid, malic acid, citric acid and fumaric acid as sole growth substrates. Complete genome analysis using single molecule real-time technology revealed that the genome consists of a 5,120,146 bp circular chromosome and a 252,328 bp megaplasmid. A series of genetic determinants associated with the carbon utilization signature of the strain were subsequently identified in the chromosome. Of note, the coexistence of genes encoding several iron-sulfur cluster independent isoenzymes in the genome indicated the importance of these enzymes in the events of iron deficiency. Synteny and comparative analysis have also unraveled the unique features of D-lactate dehydrogenase of strain S5.2 in the study. Collective information of this work has provided insights on the metabolic role of this strain in vineyard soil rhizosphere.