Throughout the past year, we have managed to do a much more detailed analysis of the existing sequencing data. We have generated assemblies from the raw sequencing data of Black Sea Teredo navalis gill tissue, which were further used
to discover the potential that the shipworms’ symbiotic microbial communities have with regard to lignocellulose degradation, as well as their taxonomic diversity and abundance at a read level. Functional annotation based on known amino-acid sequence
motifs for lignocellulolytic enzymes (derived from the CAZy database), revealed 9421 such sequences in sample SW01, and 8601 sequences in sample SW02, respectively. These sequences are associated with the catalytically active regions of all major classes of
carbohydrate-active enzymes: glycoside hydrolases (GH), glycosyl tranferases (GT), polysaccharide lyases (PL), carbohydrate esterases (CE), and auxiliary activities (AA), as well as numerous carbohydrate binding modules (CBM), which allow the CAZymes to bind
to their specific substrate.
Data analysis shows that over 70% of microorganisms identified in the Teredo navalis gill tissue samples belong to the Bacteria domain,
regardless of the location the shipworm was collected from. From this domain, approximatively 70% belong to the phylum Proteobacteria, of which a majority is represented by members of the class Gammaproteobacteria (approx. 85%). As was expected,
the Cellvibrionaceae represented the dominant family in the class, taking up approx. 80%. Surprisingly, in the case of the studied Black Sea bivalves, only a small percentage of annotated reads in each sample were associated with the Teredinidibacter
genus, the major symbiont being Cellvibrionaceae bacterium 1162T, or a similar microorganism. Cellulose enriched cultures presented a relatively large degree of diversity, dominated by members of the Gammaproteobacteria class, and
which gradually changed their composition towards a majority of anaerobic bacteria. Isolated strains stood out with their ability to produce carboxymethylcellulose-degrading enzymes capable of producing large amounts of reducing sugars, indicating the ability
to cleave numerous glycosidic bonds in a short amount of time. Comparative bioinformatics analyses were not successful in identifying a core set of genes involved exclusively in the endosymbiotic lifestyle.
I., Mereuta I.,Lascu I., Borges L.M.S., Filimon A., Stoica I., Tanase A.M., Looking for cellulolytic activity in the Black Sea shipworms gill symbionts, Biotechnology Congress 2019, April 11-13, Valencia, Spain.
Lascu I., Preda M., Mereuță I., Stoica I., Chiciudean I., Tănase AM., Evaluating the diversity and cellulolytic potential of Black Sea shipworm (Teredo navalis) gill symbionts, Biotechnology Congress 2020, September
24-26,Prague, Czech Republic.
Lascu I., Mereuță I., Chiciudean I., Hansen H., Avramescu S.M., Tănase AM., Stoica I., The complete genome sequence of Photobacterium ganghwense C2.2:
A new polyhydroxyalkanoate production candidate, submmited to MicrobiologyOpen (under review)
Chiciudean I., Lascu I., (...)Tănase AM., Stoica I., The special case of the shipworms endosymbiont Teredinibacter turnerae and the endosymbiont
status, (under project partners discussions) wil be submmited to Marine Biology Research