Caption: Marine pennate diatom frustule (Navicula sp.). The Navicula genus of diatoms comprises more than 10,000 species. The body or frustule is composed of two halves which fit tightly together. The cell walls contain silica dioxide (glass) which are preserved in deposits known as diatomaceous earth. Once hardened into rock it is called diatomite and can be used for many purposes including filters, fillers and abrasives. Diatoms represent about 25% of the plant biomass in the world. Found both in fresh water and salt water these microscopic unicellular plants are important biomass and oxygen producers. Through their photosynthesis, greenhouse gasses are converted to organic material and they therefore play a decisive role in the global carbon dioxide circulation. When individual cells die they remain as siliceous (silica dioxide) cell walls and sink to the bottom of the lake or ocean. Research has shown that the walls of fossil diatoms can give valuable information about past environment and climate conditions and serve as indicators for historical dating of sediments. Industries use the diatom silica walls in the form of diatomaceous earth for polishing material and for filtering wine and beer. In the field of nanotechnology the motility of such tiny cells and the silica cell wall design has been used as a pattern for car wheels. Omega-3 fatty acids of the diatoms have been found to benefit the nervous system. There are many phytoplankton diatom genera that are an important part of the food chain.
Magnification*: x700
Type: SEM
Copyright 2009 Dennis Kunkel Microscopy, Inc.
Keywords: 03.01.09,Naviculales,Naviculaceae,281142C,alga,algae,aquatic,diatom,eukaryote,frustule,phytoplankton,plankton,silica,skeleton,Navicula,SEM,aquatic biomass,plant biomass,photosynthesis,silica frustule,silica cell wall,frustules,oxygen producer,biomass,global carbon dioxide circulation,carbon dioxide circulation,greenhouse gas,greenhouse gasses,Heterokontophyta,photosynthetic alga,photosynthetic algae,silicious cell wall,glass cell wall,silica dioxide,fossil diatom,fossil diatoms,climate change,climate changes,biological indicator,biological indicators,biology indicator,biology indicators,nanotechnology,diatomaceous earth,polishing,filtering,omega-3 fatty acid,omega-3 fatty acids,diatom locomotion,diatom movement,environmental indicator,carbon dioxide build up,greenhouse effect,pennate marine diatom,pennate marine diatoms,marine diatoms,marine diatom,organic biomass,organic material,pennate,bacillariophyceae,bacillarophyta,pennate diatom,eukaryotes,eukaryotic,pennate diatoms,salt water pennate diatom,salt water pennate diatoms,saltwater diatom,saltwater diatoms,saltwater pennate diatom,saltwater pennate diatoms,diatom raphe,raphe,diatom frustule ornamentation,frustule ornamentation,planktonic diatom,planktonic diatoms,salt water diatom,salt water diatoms,silica skeleton