Ecology


Publications (164)

Characterization of a Pseudokeronopsis Strain (Ciliophora, Urostylida) and Its Bacterial Endosymbiont “Candidatus Trichorickettsia” (Alphaproteobacteria, Rickettsiales)

Citation
Castelli et al. (2022). Diversity 14 (12)
Names
Ca. Trichorickettsia mobilis Ca. Trichorickettsia
Subjects
Agricultural and Biological Sciences (miscellaneous) Ecological Modeling Ecology Nature and Landscape Conservation
Abstract
Symbiotic associations between bacteria and ciliate protists are rather common. In particular, several cases were reported involving bacteria of the alphaproteobacterial lineage Rickettsiales, but the diversity, features, and interactions in these associations are still poorly understood. In this work, we characterized a novel ciliate protist strain originating from Brazil and its associated Rickettsiales endosymbiont by means of live and ultrastructural observations, as well as molecular phylogeny. Though with few morphological peculiarities, the ciliate was found to be phylogenetically affiliated with Pseudokeronopsis erythrina, a euryhaline species, which is consistent with its origin from a lagoon with significant spatial and seasonal salinity variations. The bacterial symbiont was assigned to “Candidatus Trichorickettsia mobilis subsp. hyperinfectiva”, being the first documented case of a Rickettsiales associated with urostylid ciliates. It resided in the host cytoplasm and bore flagella, similarly to many, but not all, conspecifics in other host species. These findings highlight the ability of “Candidatus Trichorickettsia” to infect multiple distinct host species and underline the importance of further studies on this system, in particular on flagella and their regulation, from a functional and also an evolutionary perspective, considering the phylogenetic proximity with the well-studied and non-flagellated Rickettsia.

Genetic Diversity of “ <i>Candidatus</i> Liberibacter asiaticus” Based on Four Hypervariable Genomic Regions in China

Citation
Gao et al. (2022). Microbiology Spectrum
Names
Ca. Liberibacter asiaticus
Subjects
Cell Biology Ecology General Immunology and Microbiology Genetics Infectious Diseases Microbiology (medical) Physiology
Abstract
The hypervariable genomic regions derived from 35 published C Las genomes were used to decipher the genetic diversity of C Las strains and identify 10 new strains with high variations in prophage regions. Characterizing these variations in the C Las bacteria might provide insight into their evolution and adaptation to host plants and insects in China.

Mutual Exclusion of <i>Methanobrevibacter</i> Species in the Human Gut Microbiota Facilitates Directed Cultivation of a <i>Candidatus</i> Methanobrevibacter Intestini Representative

Citation
Low et al. (2022). Microbiology Spectrum 10 (4)
Names
Methanobrevibacter
Subjects
Cell Biology Ecology General Immunology and Microbiology Genetics Infectious Diseases Microbiology (medical) Physiology
Abstract
Methanogens are important hydrogen consumers in the gut and are associated with differing host health. Here, we determine the prevalence and abundance of archaeal species in the guts of a multi-ethnic cohort of healthy Singapore residents.

Dehalogenation of Chlorinated Ethenes to Ethene by a Novel Isolate, “ <i>Candidatus</i> Dehalogenimonas etheniformans”

Citation
Chen et al. (2022). Applied and Environmental Microbiology 88 (12)
Names
Ca. Dehalogenimonas etheniformans
Subjects
Applied Microbiology and Biotechnology Biotechnology Ecology Food Science
Abstract
Chlorinated ethenes are risk drivers at many contaminated sites, and current bioremediation efforts focus on organohalide-respiring Dehalococcoides mccartyi strains to achieve detoxification. We isolated and characterized the first non- Dehalococcoides bacterium, “ Candidatus Dehalogenimonas etheniformans” strain GP, capable of metabolic reductive dechlorination of TCE, all DCE isomers, and VC to environmentally benign ethene.

<i>Methanosaeta</i> and “ <i>Candidatus</i> Velamenicoccus archaeovorus”

Citation
Kizina et al. (2022). Applied and Environmental Microbiology 88 (7)
Names
“Velamenicoccus” “Velamenicoccus archaeovorus”
Subjects
Applied Microbiology and Biotechnology Biotechnology Ecology Food Science
Abstract
Epibiotic bacteria are known to live on and off bacterial cells. Here, we describe the ultramicrobacterial anaerobic epibiont OP3 LiM living on Archaea and Bacteria .

The “Other” <i>Rickettsiales</i> : an Overview of the Family “ <i>Candidatus</i> Midichloriaceae”

Citation
Giannotti et al. (2022). Applied and Environmental Microbiology 88 (6)
Names
Ca. Midichloriaceae
Subjects
Applied Microbiology and Biotechnology Biotechnology Ecology Food Science
Abstract
Among endosymbiotic bacterial lineages, few are as intensely studied as Rickettsiales , which include the causative agents of spotted fever, typhus, and anaplasmosis. However, an important subgroup called “ Candidatus Midichloriaceae” receives little attention despite accounting for a third of the diversity of Rickettsiales and harboring a wide range of bacteria with unique features, like the ability to infect mitochondria.