Stellwagen Bank National Marine Sanctuary (SBNMS) in the Gulf of Maine is a historic fishing ground renowned for remarkable productivity. Biodiversity conservation is a key management priority for SBNMS and yet data on the diversity of microorganisms, both prokaryotic and eukaryotic, is lacking. This study utilized next generation sequencing to characterize sedimentary communities within SBNMS at three sites over two seasons. Targeting 16S and 18S small subunit (SSU) rRNA genes and fungal Internal Transcribed Spacer (ITS) rDNA sequences, samples contained high diversity at all taxonomic levels and identified 127 phyla, including 115 not previously represented in the SBNMS Management Plan and Environmental Assessment. A majority of the diversity was bacterial, with 59 phyla, but also represented were nine Archaea, 18 Animalia, 14 Chromista, eight Protozoa, two Plantae, and 17 Fungi phyla. Samples from different sites and seasons were dominated by the same high abundance organisms but displayed considerable variation in rare taxa. The levels of biodiversity seen on this small spatial scale suggest that benthic communities of this area support a diverse array of micro- and macro-organisms, and provide a baseline for future studies to assess changes in community structure in response to rapid warming in the Gulf of Maine.

Background: Aquatic environmental DNA (eDNA) has emerged as a promising approach to identify organisms in freshwater and marine environments. While the recovery of eDNA from water most commonly involves capture of biological debris on a filter matrix, practitioners are yet to converge on standardized approaches for filtration, particularly in the field. This lack of standardization has resulted in inconsistent handling of samples following collection, limiting interpretation of results across studies and burdening groups with inconvenient storage and transport logistics that may compromise eDNA integrity. Methods: A simple to assemble and low-cost ($350 USD) water filtration system is demonstrated that can be used in field and laboratory settings to reduce time between sample acquisition and eDNA filtration, maximizing eDNA sample recovery. Quantitative PCR is used to show the utility of the platform for laboratory and marine eDNA analysis. Results: The resulting eDNA collection system is easily transported in a rugged water-resistant case, operates for more than eight hours on a 12-volt lead-acid battery, and has an unobstructed filtration rate of 150.05 ± 7.01 mL/min and 151.70 ± 6.72 mL/min with 0.22 µm and 0.45 µm Sterivex filters, respectively. We show that immediate sample filtration increases eDNA recovery in the laboratory, and demonstrate collections in aquaria and marine environments. We anticipate that providing easy to obtain, open hardware designs for eDNA sample collection will increase standardization of aquatic eDNA collection methods and improve cross-study comparisons.

Teredinibacter turnerae is a cultivable cellulolytic Gammaproteobacterium (Cellvibrionaceae) that commonly occurs as an intracellular endosymbiont in the gills of wood‐eating bivalves of the family Teredinidae (shipworms). The genome of T. turnerae encodes a broad range of enzymes that deconstruct cellulose, hemicellulose and pectin and contribute to wood (lignocellulose) digestion in the shipworm gut. However, the mechanisms by which T. turnerae secretes lignocellulolytic enzymes are incompletely understood. Here, we show that T. turnerae cultures grown on carboxymethyl cellulose (CMC) produce membrane vesicles (MVs) that include a variety of proteins identified by liquid chromatography–mass spectrometry (LC–MS/MS) as carbohydrate‐active enzymes (CAZymes) with predicted activities against cellulose, hemicellulose and pectin. Reducing sugar assays and zymography confirm that these MVs exhibit cellulolytic activity, as evidenced by the hydrolysis of CMC. Additionally, these MVs were enriched with TonB ‐dependent receptors, which are essential to carbohydrate and iron acquisition by free‐living bacteria. These observations indicate a potential role for MVs in lignocellulose utilisation by T. turnerae in the free‐living state, suggest possible mechanisms for host–symbiont interaction and may be informative for commercial applications such as enzyme production and lignocellulosic biomass conversion.

Here, we present the complete genome sequence of the Wolbachia endosymbiont w Ana, isolated from Drosophila ananassae and derived from Oxford Nanopore and Illumina sequencing. We anticipate that this will aid in Wolbachia comparative genomics and the assembly of D. ananassae specifically in regions containing extensive lateral gene transfer events.

Shipworms (Bivalvia: Teredinidae) are the most prolific wood consumers in marine environments. These wormlike marine bivalves digest wood using carbohydrate-active enzymes (CAZymes) produced by intracellular bacterial endosymbionts housed within their gills. Although several shipworm species are known to host multiple co-occurring symbiont species, the factors that influence symbiont community assembly, including the phylogenetic identity and metabolic capabilities of the symbionts, remain poorly understood. We sequenced gill symbiont metagenomes from multiple specimens of two shipworm species, Teredo bartschi (22 specimens) and Lyrodus pedicellatus (14 specimens), which have sympatric distribution in the wild, and which were reared together in laboratory co-culture. From these metagenomes, we assembled 90 metagenome-assembled genomes (MAGs) representing seven distinct symbiont species. The metagenome of each host specimen contained between 1 and 5 symbiont species, with each including at least one nitrogen-fixing symbiont. Six of the seven identified symbiont species were found in both host species, demonstrating a lack of host species specificity in these symbioses. We identified patterns of symbiont occurrence and co-occurrence in these two hosts and used these patterns to constrain the core set of CAZyme and nitrogen-fixation gene classes necessary to support host survival. Our results indicate that, in these two host species, symbiont community composition reflects the symbionts’ capabilities for carbohydrate degradation and nitrogen fixation, rather than strict species-specific mechanisms of host and symbiont sorting.

We present the complete genome sequences of two strains of Teredinibacter turnerae , SR01903 and SR02026, shipworm endosymbionts isolated from the gills of Lyrodus pedicellatus and Teredo bartschi , respectively, and derived from Oxford Nanopore sequencing. These sequences will aid in the comparative genomics of shipworm endosymbionts and symbiosis model development.