Gene expression profiling of microbial activities and interactions in sediments under haloclines of E. Mediterranean deep hypersaline anoxic basins.

Deep-sea hypersaline anoxic basins (DHABs) in the Eastern Mediterranean Sea are considered some of the most polyextreme habitats on Earth. In comparison to microbial activities occurring within the haloclines and brines of these unusual water column habitats near the Mediterranean seafloor, relatively little is known about microbial metabolic activities in the underlying sediments. In addition, it is not known whether activities are shaped by the unique chemistries of the different DHAB brines and whether evidence exists for active microbial eukaryotes in those sediments.

Revisiting the pink-red pigmented basidiomycete mirror yeast of the phyllosphere.

By taking advantage of the ballistoconidium-forming capabilities of members of the genus Sporobolomyces, we recovered ten isolates from deciduous tree leaves collected from Vermont and Washington, USA. Analysis of the small subunit ribosomal RNA gene and the D1/D2 domain of the large subunit ribosomal RNA gene indicate that all isolates are closely related. Further analysis of their physiological attributes shows that all were similarly pigmented yeasts capable of growth under aerobic and microaerophilic conditions, all were tolerant of repeated freezing and thawing, minimally tolerant to elevated temperature and desiccation, and capable of growth in liquid or on solid media containing pectin or galacturonic acid.

Inter-comparison of the potentially active prokaryotic communities in the halocline sediments of Mediterranean deep-sea hypersaline basins.

The sediment microbiota of the Mediterranean deep-sea anoxic hypersaline basins (DHABs) are understudied relative to communities in the brines and halocline waters. In this study, the active fraction of the prokaryotic community in the halocline sediments of L' Atalante, Urania, and Discovery DHABs was investigated based on extracted total RNA and 454 pyrosequencing of the 16S rRNA gene. Bacterial and archaeal communities were different in the sediments underlying the halocline waters of the three habitats, reflecting the unique chemical settings of each basin.

Structured multiple endosymbiosis of bacteria and archaea in a ciliate from marine sulfidic sediments: a survival mechanism in low oxygen, sulfidic sediments?

Marine micro-oxic to sulfidic environments are sites of intensive biogeochemical cycling and elemental sequestration, where prokaryotes are major driving forces mediating carbon, nitrogen, sulfur, phosphorus, and metal cycles, important from both biogeochemical and evolutionary perspectives. Associations between single-celled eukaryotes and bacteria and/or archaea are common in such habitats. Here we describe a ciliate common in the micro-oxic to anoxic, typically sulfidic, sediments of Santa Barbara Basin (CA, USA).

Phototrophic utilization of taurine by the purple nonsulfur bacteria Rhodopseudomonas palustris and Rhodobacter sphaeroides.

Taurine metabolism by two phototrophically grown purple nonsulfur bacteria enrichment isolates has been examined. Rhodopseudomonas palustris (strain Tau1) grows with taurine as a sole electron donor, sulfur and nitrogen source during photoautotrophic growth. Rhodobacter sphaeroides (strain Tau3) grows on the compound as sole electron donor, sulfur and nitrogen source, and partial carbon source, in the presence of CO(2) during photoheterotrophic growth.

Sulfoacetaldehyde bisulfite adduct is a substrate for enzymes presumed to act on sulfoacetaldehyde.

Sulfoacetaldehyde, an intermediate of interest to those studying microbial metabolism of sulfonates, is commonly synthesized as the bisulfite adduct. A published method presumed to convert this to the free aldehyde (and cited several times elsewhere in the literature) has been shown to be ineffective; this had not been realized by its users because the enzymes under study recognize the adduct as a substrate.

Acetate acts as a protonophore and differentially affects bead movement and cell migration of the gliding bacterium Cytophaga johnsonae (Flavobacterium johnsoniae).

Cells of Cytophaga johnsonae (now Flavobacterium johnsoniae) are able to translocate on solid surfaces but are unable to swim in liquid media. Organelles that may be involved in this gliding motility have not been detected, and the mechanism(s) responsible remains unknown. The movement of latex beads attached to the cell surface is considered by some to be a manifestation of the gliding machinery.