Welcome back to my blog! This week we will be diving through the cell structure of Chlorophyta, which is commonly known as green algae in microbiology. Green algae are very similar to plants and are closely connected to plants phylogenetically. Green algae are unicellular, multicellular, colonial, or coenocytic eukaryotes that obtain nourishment by photosynthesis. They are eukaryotic so this means they contain a nucleolus. They grow and inhabit freshwater, saltwater or in aquatic environments. Some green algae grow on and inside rocks. The green algae that cover the Bosphorus have made this body of water their special home as access to food and nutrients in a good environment. Members of the green algae expand to more than 7,000 species on planet Earth. The green alga Ostreococcus tauri is a common unicellular species of marine phytoplankton that has a diameter of approximately 2 μm. At the colonial level in green algae comes the microbe Volvox. This alga forms colonies composed of several hundred flagellated cells and contains 15, 634 genes. Most of the Volvox are motile while some carry out photosynthesis and others specialize in reproduction. Dunaliella is a single-celled, flagellated green alga which is about 5 μm wide and contains 18,801 genes. The plant-like green alga, Chara. Micrasterias is a multilobed cell which is about 100 μm wide. Many of the green algae are not motile but if they are, the flagella will be attached to the single cell and colonial green algae. The motile single-celled can be spherical, oblong pear-shaped and also elongated. According to a gram stain of algae (cyanobacteria), this microbe is classified as a gram-negative bacterium. Green algae have chloroplasts that contain chlorophyll giving them a bright green color. This microbe’s cell walls contain cellulose and they store carbohydrate in the form of starch. They do not have roots, stems, or leaves but they still resemble plants a lot. Don’t forget to visit back next week to read about the life cycle of the green algae!
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Algae Cell Division under the microscope.
Resources:
https://genome.jgi.doe.gov/algae/algae.info.html
Images and information: Brock Biology of Microorganisms, 15thEdition. Madigan, Martinko, Stahl & Clark.