Subgroup Characteristics of Marine Methane-Oxidizing ANME-2 Archaea and Their Syntrophic Partners as Revealed by Integrated Multimodal Analytical Microscopy.
Shawn Erin McGlynnGrayson L ChadwickAriel O'NeillMason MackeyAndrea ThorThomas J DeerinckMark H EllismanVictoria J OrphanPublished in: Applied and environmental microbiology (2018)
Phylogenetically diverse environmental ANME archaea and sulfate-reducing bacteria cooperatively catalyze the anaerobic oxidation of methane oxidation (AOM) in multicelled consortia within methane seep environments. To better understand these cells and their symbiotic associations, we applied a suite of electron microscopy approaches, including correlative fluorescence in situ hybridization-electron microscopy (FISH-EM), transmission electron microscopy (TEM), and serial block face scanning electron microscopy (SBEM) three-dimensional (3D) reconstructions. FISH-EM of methane seep-derived consortia revealed phylogenetic variability in terms of cell morphology, ultrastructure, and storage granules. Representatives of the ANME-2b clade, but not other ANME-2 groups, contained polyphosphate-like granules, while some bacteria associated with ANME-2a/2c contained two distinct phases of iron mineral chains resembling magnetosomes. 3D segmentation of two ANME-2 consortium types revealed cellular volumes of ANME and their symbiotic partners that were larger than previous estimates based on light microscopy. Polyphosphate-like granule-containing ANME (tentatively termed ANME-2b) were larger than both ANME with no granules and partner bacteria. This cell type was observed with up to 4 granules per cell, and the volume of the cell was larger in proportion to the number of granules inside it, but the percentage of the cell occupied by these granules did not vary with granule number. These results illuminate distinctions between ANME-2 archaeal lineages and partnering bacterial populations that are apparently unified in their ability to perform anaerobic methane oxidation.IMPORTANCE Methane oxidation in anaerobic environments can be accomplished by a number of archaeal groups, some of which live in syntrophic relationships with bacteria in structured consortia. Little is known of the distinguishing characteristics of these groups. Here, we applied imaging approaches to better understand the properties of these cells. We found unexpected morphological, structural, and volume variability of these uncultured groups by correlating fluorescence labeling of cells with electron microscopy observables.
Keyphrases
- electron microscopy
- single cell
- anaerobic digestion
- induced apoptosis
- cell therapy
- microbial community
- single molecule
- high resolution
- cell cycle arrest
- wastewater treatment
- hydrogen peroxide
- sewage sludge
- randomized controlled trial
- clinical trial
- high throughput
- magnetic resonance imaging
- stem cells
- nitric oxide
- oxidative stress
- hiv testing
- deep learning
- signaling pathway
- endoplasmic reticulum stress
- high speed
- human immunodeficiency virus
- electron transfer
- heavy metals
- quantum dots
- convolutional neural network