Back to Search
Start Over
Characterisation of the enzyme transport path between shipworms and their bacterial symbionts
- Source :
- BMC Biology, Vol 19, Iss 1, Pp 1-18 (2021), BMC Biology
- Publication Year :
- 2021
- Publisher :
- BMC, 2021.
-
Abstract
- Background Shipworms are marine xylophagus bivalve molluscs, which can live on a diet solely of wood due to their ability to produce plant cell wall-degrading enzymes. Bacterial carbohydrate-active enzymes (CAZymes), synthesised by endosymbionts living in specialised shipworm cells called bacteriocytes and located in the animal’s gills, play an important role in wood digestion in shipworms. However, the main site of lignocellulose digestion within these wood-boring molluscs, which contains both endogenous lignocellulolytic enzymes and prokaryotic enzymes, is the caecum, and the mechanism by which bacterial enzymes reach the distant caecum lumen has remained so far mysterious. Here, we provide a characterisation of the path through which bacterial CAZymes produced in the gills of the shipworm Lyrodus pedicellatus reach the distant caecum to contribute to the digestion of wood. Results Through a combination of transcriptomics, proteomics, X-ray microtomography, electron microscopy studies and in vitro biochemical characterisation, we show that wood-digesting enzymes produced by symbiotic bacteria are localised not only in the gills, but also in the lumen of the food groove, a stream of mucus secreted by gill cells that carries food particles trapped by filter feeding to the mouth. Bacterial CAZymes are also present in the crystalline style and in the caecum of their shipworm host, suggesting a unique pathway by which enzymes involved in a symbiotic interaction are transported to their site of action. Finally, we characterise in vitro four new bacterial glycosyl hydrolases and a lytic polysaccharide monooxygenase identified in our transcriptomic and proteomic analyses as some of the major bacterial enzymes involved in this unusual biological system. Conclusion Based on our data, we propose that bacteria and their enzymes are transported from the gills along the food groove to the shipworm’s mouth and digestive tract, where they aid in wood digestion.
- Subjects :
- Gill
Proteomics
animal structures
Physiology
QH301-705.5
Plant Science
Biology
Food groove
General Biochemistry, Genetics and Molecular Biology
Caecum
Structural Biology
Crystalline style
Animals
Glycoside hydrolase
Biology (General)
Symbiosis
Ecology, Evolution, Behavior and Systematics
Phylogeny
chemistry.chemical_classification
Bacteria
Lyrodus pedicellatus
Cell Biology
biology.organism_classification
Mucus
Bivalvia
Shipworm
Enzyme
Biochemistry
chemistry
Wood-borers
General Agricultural and Biological Sciences
Digestion
Lignocellulose
CAZymes
Developmental Biology
Biotechnology
Symbiotic bacteria
Research Article
Subjects
Details
- Language :
- English
- ISSN :
- 17417007
- Volume :
- 19
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- BMC Biology
- Accession number :
- edsair.doi.dedup.....f79a97453162ad9f8174ef88f8531ba4