Microbial Communities on Plastic Polymers in the Mediterranean Sea.

Plastic particles in the ocean are typically covered with microbial biofilms, but it remains unclear whether distinct microbial communities colonize different polymer types. In this study, we analyzed microbial communities forming biofilms on floating microplastics in a bay of the island of Elba in the Mediterranean Sea. Raman spectroscopy revealed that the plastic particles mainly comprised polyethylene (PE), polypropylene (PP), and polystyrene (PS) of which polyethylene and polypropylene particles were typically brittle and featured cracks.

Bacterial communities in temperate and polar coastal sands are seasonally stable.

Coastal sands are biocatalytic filters for dissolved and particulate organic matter of marine and terrestrial origin, thus, acting as centers of organic matter transformation. At high temporal resolution, we accessed the variability of benthic bacterial communities over two annual cycles at Helgoland (North Sea), and compared it with seasonality of communities in Isfjorden (Svalbard, 78°N) sediments, where primary production does not occur during winter. Benthic community structure remained stable in both, temperate and polar sediments on the level of cell counts and 16S rRNA-based taxonomy.

Bacterioplankton reveal years-long retention of Atlantic deep-ocean water by the Tropic Seamount.

Seamounts, often rising hundreds of metres above surrounding seafloor, obstruct the flow of deep-ocean water. While the retention of deep-water by seamounts is predicted from ocean circulation models, its empirical validation has been hampered by large scale and slow rate of the interaction. To overcome these limitations we use the growth of planktonic bacteria to assess the retention time of deep-ocean water by a seamount.

Microbial life on a sand grain: from bulk sediment to single grains.

Globally, marine surface sediments constitute a habitat for estimated 1.7 × 10 prokaryotes. For benthic microbial community analysis, usually, several grams of sediment are processed.

Modification of a High-Throughput Automatic Microbial Cell Enumeration System for Shipboard Analyses.

In the age of ever-increasing "-omics" studies, the accurate and statistically robust determination of microbial cell numbers within often-complex samples remains a key task in microbial ecology. Microscopic quantification is still the only method to enumerate specific subgroups of microbial clades within complex communities by, for example, fluorescence in situ hybridization (FISH). In this study, we improved an existing automatic image acquisition and cell enumeration system and adapted it for usage at high seas on board an oceanographic research ship.

Transcriptional response of the model planctomycete Rhodopirellula baltica SH1(T) to changing environmental conditions.

Background: The marine model organism Rhodopirellula baltica SH1(T) was the first Planctomycete to have its genome completely sequenced. The genome analysis predicted a complex lifestyle and a variety of genetic opportunities to adapt to the marine environment. Its adaptation to environmental stressors was studied by transcriptional profiling using a whole genome microarray.

Evaluation of gene expression analysis using RNA-targeted partial genome arrays.

Highly parallel cDNA targeting microarrays have been established over the last years as the quasi-standard for genome wide expression profiling in pro- and eukaryotes. Protocols for the direct detection of RNA or aRNA (amplified RNA) are currently emerging. This allows to circumvent the bias introduced by enzymatic target molecule preparation.