Cyanobacteria known as Cyanophyta, are a phylum consisting of free-living photosynthetic bacteria and the endosymbiotic plastids, a sister group to Gloeomargarita, that are present in some eukaryotes. They obtain their energy through oxygenic photosynthesis; the oxygen gas in the atmosphere of earth is produced by cyanobacteria of this phylum, either as free-living bacteria or as the endosymbiotic plastids. The name cyanobacteria comes from the color of the bacteria. Cyanobacteria, which are prokaryotes, are called "blue-green algae", though some modern botanists restrict the term algae to eukaryotes. Cyanobacteria appear to have originated in a terrestrial environment. Unlike heterotrophic prokaryotes, cyanobacteria have internal membranes; these are flattened. Phototrophic eukaryotes such as green plants perform photosynthesis in plastids that are thought to have their ancestry in cyanobacteria, acquired long ago via a process called endosymbiosis; these endosymbiotic cyanobacteria in eukaryotes evolved and differentiated into specialized organelles such as chloroplasts and leucoplasts.
By producing and releasing oxygen, cyanobacteria are thought to have converted the early oxygen-poor, reducing atmosphere into an oxidizing one, causing the Great Oxygenation Event and the "rusting of the Earth", which changed the composition of the Earth's life forms and led to the near-extinction of anaerobic organisms. Cyanobacteria produce a range of toxins known as cyanotoxins that can pose a danger to humans and animals; the cyanobacteria Synechocystis and Cyanothece are important model organisms with potential applications in biotechnology for bioethanol production, food colorings, as a source of human and animal food, dietary supplements and raw materials. Cyanobacteria are a group of photosynthetic bacteria, some of which are nitrogen-fixing, that live in a wide variety of moist soils and water either or in a symbiotic relationship with plants or lichen-forming fungi, they include colonial species. Colonies may form filaments, sheets, or hollow spheres; some filamentous species can differentiate into several different cell types: vegetative cells – the normal, photosynthetic cells that are formed under favorable growing conditions.
Some cyanobacteria can fix atmospheric nitrogen in anaerobic conditions by means of specialized cells called heterocysts. Heterocysts may form under the appropriate environmental conditions when fixed nitrogen is scarce. Heterocyst-forming species are specialized for nitrogen fixation and are able to fix nitrogen gas into ammonia, nitrites or nitrates, which can be absorbed by plants and converted to protein and nucleic acids. Free-living cyanobacteria are present in the water of rice paddies, cyanobacteria can be found growing as epiphytes on the surfaces of the green alga, where they may fix nitrogen. Cyanobacteria such as Anabaena can provide rice plantations with biofertilizer. Many cyanobacteria form motile filaments of cells, called hormogonia, that travel away from the main biomass to bud and form new colonies elsewhere; the cells in a hormogonium are thinner than in the vegetative state, the cells on either end of the motile chain may be tapered. To break away from the parent colony, a hormogonium must tear apart a weaker cell in a filament, called a necridium.
Each individual cell has a thick, gelatinous cell wall. They lack flagella. Many of the multicellular filamentous. In water columns, some cyanobacteria float by forming gas vesicles, as in archaea; these vesicles are not organelles as such. They are not bounded by a protein sheath. Cyanobacteria can be found in every terrestrial and aquatic habitat—oceans, fresh water, damp soil, temporarily moistened rocks in deserts, bare rock and soil, Antarctic rocks, they can form phototrophic biofilms. They are found in endolithic ecosystem. A few are endosymbionts in lichens, various protists, or sponges and provide energy for the host; some live in the fur of sloths. Aquatic cyanobacteria are known for their extensive and visible blooms that can form in both freshwater and marine environments; the blooms can have the appearance of blue-green scum. These blooms can be toxic, lead to the closure of recreational waters when spotted. Marine bacteriophages are significant parasites of unicellular marine cyanobacteria.
Cyanobacterial growth is favored in ponds and lakes where waters are calm and have little turbulent mixing. Their life cycles are disrupted when the water or artificially mixes from churning currents caused by the flowing water of streams or the churning water of fountains. For this reason blooms of cyanobacteria occur in rivers unless the water is flowing slowly. Growth is favored at higher temperatures which enable Microcystis species to outcompete
SS Stephen Furdek was a Liberty ship built in the United States during World War II. She was named after Stephen Furdek, a Roman Catholic priest, co-founder of the First Catholic Slovak Union known as Jednota, an ardent activist for Slovak identity and nationhood. Stephen Furdek was laid down on 16 March 1944, under a Maritime Commission contract, MC hull 2299, by J. A. Jones Construction, Panama City, Florida, she was allocated to Merchants & Miners Transportation Company, on 23 May 1944. On 27 September 1948, she was laid up in Mobile, Alabama. On 13 May 1970, she was sold, along with SS Isaac M. Singer, for $61,202.08 to Union Minerals and Alloys Corporation, for scrapping. She was withdrawn from the fleet on 1 June 1970
Roam Sweet Home is a 1996 American documentary film directed by Ellen Spiro. In road-trip style, it follows the lives of retirees who live on the road full-time in trailers, due to economic necessity, pleasure, or both. Filmmaker Spiro and her dog, join a community of American nomads in order to explore their unconventional lifestyle first hand. Through Spiro's innovative and interpersonal style of filmmaking she captures the spirit of the roamers and the wide variety of reasons they abandoned the more traditional means of retirement. One group of women discusses the thrill of independence and sheer freedom they discovered after escaping repressive relationships. Another expounds upon the pleasures of traveling unencumbered throughout the country; the film is narrated by Spiro's dog, with the voice provided by Allan Gurganus, who shares his perspective on the whims and follies of human nature. Aging himself, Sam adds an emotional perspective through his musings on death and the journey through life.
Grand Prize at the Big Muddy Film Festival National Media Owl award presented by Gene Siskel for the Retirement Research Foundation Johnson, Jerry. Roam Sweet Home. Austin Chronicle. 1997-11-7. Retrieved on 2007-6-12. McDonald, Scott; the Garden in the Machine: A Field Guide to Independent Films About Place. University of California Press. Berkeley and Los Angeles California. 2001. Retrieved on 2007-6-25. Roam Sweet Home: ITVS presents Ellen Spiro's Inside Look at Life on the Road. Independent Television Service. 1997-5-28. Retrieved on 2007-6-12. Independent Television Service: Press Release. 1997-5-28. Retrieved on 2007-6-12. Roam Sweet Home Official Website Roam Sweet Home on IMDb