Confocal Raman Micro-Spectroscopy Application On The Environmental Adaptability Mechanism Of Bathymodiolus Platifrons

There is a kind of chemosynthesis-based ecosystem in deep-sea extreme environment,which is different from coastal ecosystem based on photosynthesis to product matter conversion and energy flow.Chemoautotrophic bacteria,as the primary producers,are able to oxidize hydrogen sulfide and methane to supply nutrition and energy for the whole ecosystem.Bathymodiolus platifrons are the dominant species of deep-sea chemosynthesis-based ecosystem and the model species for researching the deep-sea symbiotic system.They can attach to hard-substrate authigenic carbonate rock by byssus and have extensive adaption for marine environment.Different from the mussels on the shallow sea,which acquire food by filtering plankton or particulate organic matter,Bathymodiolus platifrons harbour substantial symbionts which are located in the gill epithelial cells-bacteriocytes and can utilize methane and hydrogen to provide main energy and nutritive substance for hosts.The successful symbiosis between marine metazoans and chemoautotrophic microorganisms sustains the life activities of deep-sea biological community.With further research,the shortcomings of traditional techniques in the study of deep-sea life processes have gradually become prominent.Raman spectroscopy technique can provide molecular structure information and distribution characteristics of biological tissue and single cell duo to the non-destructive and non-invasive in situ detection,which opens the new windows for deep sea life process research.In this paper,Bathymodiolus platifrons distributing widely in the South China Sea are chosen in order to preliminarily inquire its symbiosis and the adaption mechanism for the various environment conditions by detection the symbiotic and the aposymbiotic Bathymodiolus platifrons gill filaments,the aposymbiotic Bathymodiolus platifrons gill cell,the foot tissue of the Bathymodiolus platifrons and Mytilus edulis.The conclusions are the followings:?1?The morphology and components of symbiotic and aposymbiotic Bathymodiolus platifrons gill filaments exist significant changes.Symbiotic gill filaments present fuller and the central cavity more centrally distributed;The chemical components change after the aposymbiotic culture.The Raman spectra of methanotrophs presents a high intensity peak at 749 cm^-1,which may serve as a marker spectra for screening for methanotrophs.?2?The Raman spectra showed that the components of gill cells were mainly composed of lipid,protein and nucleic acid,which is similar to the common animal cells in morphology and substance composition.The characteristic peaks of DNA(789cm^-1),phenylalanine(1006 cm^-1),and lipid(1747 cm^-1),represent the nucleus,cytoplasm and cell membranes respectively to be integrated 2 D Raman color-coded image of gill cells,which presents intuitively the morphological structure and component distribution of the cells.?3?The Bathymodiolus platifrons and Mytilus edulis vary in byssus,which depend upon the characteristic distribution of mussel foot glands and is a kind of adaption mechanism for marine environment.The byssus of Bathymodiolus platifrons is 5.7 wider than that of the Mytilus edulis,and its cuticle is rougher.The distribution of foot glands is more dispersive.The Byssus is the external manifestation of foot glands.The apparent differences of foot byssus of mussel in different sea areas originate from the characteristic distribution of foot glands,which is a kind of adaptation mechanism of mussels to environment.