To investigate the timing and intensity of winter spawning by coastal invertebrates, we enumerated embryos in plankton samples collected in daily time series from January to March of 2014 (79 d), 2015 (73 d), and 2016 (74 d). Samples were collected near the mouth of the Coos Bay estuary in Oregon. We enumerated several hundred different morphologically distinct types of embryos and larvae representing at least five phyla. Forty‐three embryo types were abundant enough (abundance > 500 over the time series) to enable statistical analysis. Twenty of these types were identified using genetic barcoding of which there were four nemerteans, four gastropods, four chitons, five polychaetes, and two echinoderms. In winter 2014, hydrographic conditions were similar to average historical values. Conditions in 2015 and 2016 were characterized by marine heat waves (MHWs). In 2015, the “warm blob”—anomalously warm water in the Northeastern Pacific—affected conditions and in 2016, there was a strong El Niño. In 2015 and 2016, winter spawning intensity was orders of magnitude lower than in 2014 and many taxa failed to spawn (11 and 24 in 2015 and 2016, respectively); spawning appears to have been adversely impacted by the MHWs. The MHW of 2015 has been attributed to anthropogenic global climate change while the 2016 El Niño may have been strengthened by climate change. The frequency, intensity, and duration of MHW are projected to increase dramatically with global warming, which may adversely affect reproduction and recruitment by numerous marine taxa.

Developing a laboratory model of oral polymicrobial communities is essential for in vitro studies of the transition from healthy to diseased oral plaque. SHI medium is an enriched growth medium capable of supporting in vitro biofilms with similar diversity to healthy supragingival inocula; however, this medium does not maintain the diversity of gram‐negative bacteria more associated with subgingival plaque. Here, we systematically modified SHI medium components to investigate the impacts of varying nutrients and develop a medium capable of supporting a specific disease‐state subgingival community. A diseased subgingival plaque sample was inoculated in SHI medium with increasing concentrations of sucrose (0%, 0.1%, 0.5%), fetal bovine serum (FBS) (0%, 10%, 20%, 30%, 50%), and mucin (0.1, 2.5, 8.0 g/L) and grown for 48 hrs, then the 16S rRNA profiles of the resulting biofilms were examined. In total, these conditions were able to capture 89 of the 119 species and 43 of the 51 genera found in the subgingival inoculum. Interestingly, biofilms grown in high sucrose media, although dominated by acidogenic Firmicutes with a low final pH, contained several uncultured taxa from the genus Treponema, information that may aid culturing these periodontitis‐associated fastidious organisms. Biofilms grown in a modified medium (here named subSHI‐v1 medium) with 0.1% sucrose and 10% FBS had a high diversity closest to the inoculum and maintained greater proportions of many gram‐negative species of interest from the subgingival periodontal pocket (including members of the genera Prevotella and Treponema, and the Candidate Phyla Radiation phylum Saccharibacteria), and therefore best represented the disease community.

Candidate phylum radiation (CPR) bacteria comprise a poorly understood phylum that is estimated to encompass ∼26% of all diversity of domain bacteria. Among CPR bacteria, the Saccharibacteria lineage (TM7) is of particular interest, as it is found in high abundance in the mammal microbiome and has been associated with oral disease.

Nanosynbacter lyticus type strain TM7x is the first cultivated member of the Saccharibacteria and the candidate phyla radiation (CPR). It was discovered to be ultrasmall in cell size with a highly reduced genome that establishes an obligate epibiotic relationship with its host bacterium.

No abstract