Assessments of Temporal Variations in Haplotypes of 'Candidatus Liberibacter solanacearum' and Its Vector, the Potato Psyllid, in Potato Fields and Native Vegetation.

The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), had been known for nearly a century to cause psyllid yellows of solanaceous crops. However, it has only been a decade since the insect was discovered to transmit the bacterium 'Candidatus Liberibacter solanacearum' (Lso), which putatively causes potato zebra chip disease. This project was initiated to quantify temporal incidences of haplotypes of the psyllid (Central, Southwestern, and Western) and Lso (A, B) in potato fields and in native vegetation. Psyllids were collected from native vegetation in Texas (2011-2014), and from potato fields in Texas and New Mexico (2014-2017). Psyllids were tested for Lso and haplotypes of both psyllid and Lso. In Texas, the Central psyllid haplotype was overwhelmingly dominant both in potato fields and in native vegetation regardless of location and time of collection. However, in New Mexico potato fields, although the Southwestern haplotype was overall dominant, the ratios of individual haplotypes varied among years and within a season. The Southwestern psyllid haplotype was greater in incidence than the Central early but declined later in the season in each of the 4 yr, while the Central haplotype was low in incidence early but increased over time. Lso was detected in all three psyllid haplotypes representing the first report in Southwestern psyllid haplotype. In Texas, Lso haplotype A was more frequently detected than B, but in New Mexico the incidence of positive psyllids was not high enough to make definitive conclusions regarding predominant Lso haplotype.

Genome sequence of Nitratireductor indicus type strain C115.

Nitratireductor indicus strain C115(T) was isolated from a crude-oil-degrading consortium enriched from deep seawater of the Indian Ocean. Here, we present the draft genome of strain C115(T), which contains 4,992,479 bp with a G+C content of 60.8% and contains 4,825 protein-coding genes and 45 tRNA genes.

Parvibaculum hydrocarboniclasticum sp. nov., a mesophilic, alkane-oxidizing alphaproteobacterium isolated from a deep-sea hydrothermal vent on the East Pacific Rise.

An aerobic, alkane-oxidizing bacterium, designated strain EPR92(T), was isolated from hydrothermal fluids that had been collected from a deep-sea vent on the East Pacific Rise (at 9° 50' N 104° 17' W). The cells of the novel strain were Gram-staining-negative rods that measured approximately 1.4 µm in length and 0.4 µm in width. Strain EPR92(T) grew at 20-40 °C (optimum 35 °C), with1.0-5.0% (w/v) NaCl (optimum 2.5%), and at pH 4.0-8.5 (optimum pH 7.5). The generation time under optimal conditions was 63 min. Strain EPR92(T) grew aerobically in artificial seawater minimal medium with n-alkanes as sole carbon and energy sources, and also in artificial seawater medium supplemented with peptone and yeast extract. The predominant fatty acids were C(18:1)ω7c, C(19:0) cyclo ω8c, 11-methyl C(18:1)ω7c and a putative C(12:0) aldehyde. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and four unidentified aminolipids. The major respiratory quinone was Q-10 and the genomic DNA G+C content was 60.7 mol%. Phylogenetic analyses of the 16S rRNA gene showed that strain EPR92(T) belongs in the class Alphaproteobacteria and the recognized species that were most closely related to the novel strain were identified as Parvibaculum indicum P-31(T) (98.7% sequence similarity) and Parvibaculum lavamentivorans DS-1(T) (95.8%). In DNA-DNA hybridizations, the level of DNA-DNA relatedness observed between strain EPR92(T) and P. indicum P-31(T) was 47.7%, indicating that the two strains do not belong to the same species. Based on the phylogenetic, physiological, chemotaxonomic and genetic evidence, strain EPR92(T) represents a novel species within the genus Parvibaculum, for which the name Parvibaculum hydrocarboniclasticum sp. nov. is proposed. The type strain is EPR92(T) ( = DSM 23209 = JCM 16666(T)).