Publications

4868

Abstract Nitrification, the microbial oxidation of ammonia to nitrate via nitrite, occurs in a wide range of acidic soils. However, the ammonia-oxidizing bacteria (AOB) that have been isolated from soil to date are acid-sensitive. Here we report the isolation and characterization of an acid-adapted AOB from an acidic agricultural soil. The isolated AOB, strain TAO100, is classified within the Gammaproteobacteria based on phylogenetic characteristics. TAO100 can grow in the pH range of 5–7.5 and survive in highly acidic conditions until pH 2 by forming cell aggregates. Whereas all known gammaproteobacterial AOB (γ-AOB) species, which have been isolated from marine and saline aquatic environments, are halophiles, TAO100 is not phenotypically halophilic. Thus, TAO100 represents the first soil-originated and non-halophilic γ-AOB. The TAO100 genome is considerably smaller than those of other γ-AOB and lacks several genes associated with salt tolerance which are unnecessary for survival in soil. The ammonia monooxygenase subunit A gene of TAO100 and its transcript are higher in abundance than those of ammonia-oxidizing archaea and betaproteobacterial AOB in the strongly acidic soil. These results indicate that TAO100 plays an important role in the nitrification of acidic soils. Based on these results, we propose TAO100 as a novel species of a new genus, Candidatus Nitrosoglobus terrae.

ABSTRACT We report here four draft genome sequences belonging to clade F of the cyanobacterium “ Candidatus Synechococcus spongiarum” of the marine sponge Aplysina aerophoba , which were collected from two nearby locations in the northern Adriatic Sea. The sequences provide the basis for within-clade comparisons between members of this widespread group of cyanobacterial sponge symbionts.

ABSTRACT Here, we report the genome of “ Candidatus Carsonella ruddii” strain BC, a nutritional endosymbiont of the tomato psyllid Bactericera cockerelli . The 173,802-bp genome contains 198 protein-coding genes, with a G+C content of 14.8%.

AbstractWe present the draft genome of an anaerobic ammonium-oxidizing (anammox) bacterium, cluster IIICandidatusBrocadia, which was enriched in an anammox reactor. A 3.2 Mb genome sequence comprising 168 contigs was assembled, in which 2,765 gene-coding regions, 47 tRNAs, and 5S, 16S and 23S ribosomal RNAs were annotated. No evidence for the presence of a nitric oxide-forming nitrite reductase was found.

Bacteria that directly use electrodes as metabolic electron donors (biocathodes) have been proposed for applications ranging from microbial electrosynthesis to advanced bioelectronics for cellular communication with machines. However, just as we understand very little about oxidation of analogous natural insoluble electron donors, such as iron oxide, the organisms and extracellular electron transfer (EET) pathways underlying the electrode-cell direct electron transfer processes are almost completely unknown. Biocathodes are a stable biofilm cultivation platform to interrogate both the rate and mechanism of EET using electrochemistry and to study the electroautotrophic organisms that catalyze these reactions. Here we provide new evidence supporting the hypothesis that the uncultured bacterium “CandidatusTenderia electrophaga” directly couples extracellular electron transfer to CO2fixation. Our results provide insight into developing biocathode technology, such as microbial electrosynthesis, as well as advancing our understanding of chemolithoautotrophy.

Abstract‘Candidatus Liberibacter asiaticus’ (CaLas), associated with citrus Huanglongbing (HLB), is a non culturable member of the α-proteobacteria. In this study serologically based methods for the detection of CaLas were developed. An anti-outer membrane protein A (OmpA) polyclonal antibody previously produced (in our laboratory) was highly effective for the detection of CaLas from citrus tissues in a simple tissue printing format. The antibody was also used to capture bacteria from periwinkle extracts. About 80% of all field samples analyzed tested positive with both immune tissue printing and qPCR; whereas 95% were positive with at least one of these two methods. When asymptomatic citrus tissues were tested, the tissue printing method gave a higher rate of detection (83%) than the qPCR method (64%). This is consistent with a lower concentration of CaLas DNA, but a higher proportion of viable cells, in the asymptomatic tissues. The immune tissue printing method also highlights the detail of the spatial distribution of ‘Ca. Liberibacter asiaticus’ in diseased citrus tissues. Both the immune capture PCR and immune tissue printing methods offer the advantages of low cost, high throughput, ease of scaling for multiple samples and simplicity over current PCR-based methods for the detection of ‘Ca. Liberibacter asiaticus’.

ABSTRACT We report here the draft genome sequence of “ Candidatus Liberibacter asiaticus” strain TX2351, collected from Asian citrus psyllids in south Texas, USA. The TX2351 genome has a size of 1,252,043 bp, a G+C content of 36.5%, 1,184 predicted open reading frames, and 52 RNA genes.