Bacteria & History and ecology

The word bacteria is normally associated with disease-causing organisms, interchangeable the streptococcus bacteria. While there atomic number 18 a considerable number of pathogenic bacteria that are infamous for such diseases as cholera, tuberculosis, and gonorrhea, such disease-causing species are a comparatively tiny fraction of the bacteria as a whole. There are approximately five nonillion (5? 1030) bacteria in the world. Bacteria are so widespread that it is possible only to make the most general statements about their life history and environmental science (Berkeley Free Clinic, 1).There are bacteria that plays main(prenominal) role in the global ecosystem. They may be implant on the tops of mountains, the bottom of the mysticest oceans, in the guts of animals, and even in the frozen rocks and ice of Antarctica. i feature that has enabled them to spread so far, and last so long is their ability to go dormant for an widen period. There are specific methods in order to study and observe bacteria because they are non visible to the naked eye. Even with the use of microscope they are rattling(prenominal) problematic to spot without adding some stains that would pass on them visible.DETAILS Properties Bacteria are prokaryotic (no membrane-enclosed nucleus) that do not determine mitochondria or chloroplasts. They have one chromosome that are composed of close circle of double-stranded DNA with no associated histones. If flagella are present, they are made of a single filament of the protein flagellin there are none of the 9+2 tubulin-containing microtubules of the eukaryotes (Users. rcn. com, 1). Their ribosomes differ from those of the eukaryotes. Bacteria have a rigid cell wall made of peptidoglycan that allows them to survive at long periods of time.They do not manage mitosis and mostly reproduce through asexual reproduction. Any form of sexual reproduction varies differently from the eukaryotes because they do not perform meiosis. The pla sma membrane is a phospholipid bilayer however contains no cholesterol or new(prenominal) steroids (Users. rcn. com, 1). Most of bacteria form a single spore when their food supply runs low. This is the reason why pathogenic bacteria become infectious at the later part of the attack. Most of the water is removed from the spore and metamorphosis ceases.Spores are so resistant to adverse conditions of dryness and temperature that they may remain viable even after 50 years of dormancy (Users. rcn. com, 1). Environmental and Nutritive Requirements Most bacteria can be separate advertisement according to their response to oxygen. These are consist of three distinct group, Aerobic bacteria which thrives in the armorial bearing of oxygen, Anaerobic which cannot tolerate gaseous oxygen, and facultative anaerobes which prefer growing in the presence of oxygen but are able to survive without it. Aerobic bacteria require oxygen for their continued growth and existence.On the former(a) ha nd anaerobic cannot survive in the presence of gaseous oxygen. These bacteria live in deep underwater sediments, or in oxygen deprived environment such as those that cause bacterial food poisoning. Bacteria also differ in the mode and source of their energy. There are Heterotrophs that recoup energy from breaking down complex organic compounds that they must take in from the environment. This includes saprobic bacteria found in decaying material, as well as those that rely on fermentation or respiration.The another(prenominal) group, the autotrophs, fix carbon dioxide to make their own food source this may be fueled by light energy (photoautotrophic), or by oxidation of nitrogen, sulfur, or other elements (chemoautotrophic) (Berkeley Free Clinic, 2). Chemoautotrophs are unmatched while photoautotrophs are more common and quite diverse. One particular bacteria offers a very interesting behavior because they use hydrogen sulfide as hydrogen donor, instead of water like most other p hotosynthetic organisms, including cyanobacteria.There are green sulfur bacteria and purple sulfur bacteria, otherwise Bacteria include the cyanobacteria, and purple nonsulfur bacteria. Role in the Global Ecosystem Bacteria play a very consequential role in maintaining the balance of our ecosystem. Through their ceaseless labor, they cycle nutrients such as carbon, nitrogen, and sulfur. For exemplification without bacteria to decompose rotten objects, our CO2 would have been depleted and all our plants would have ceased to exist. The process of bunk releases nutrients back into the environment for plants and other living organisms.Bacteria also cycle nitrogen in the soil. Nitrogen is important for plants health and growth. Without these cycling processes all our plants would die and then humanity would have ran out of food. thou filthiness Bacteria happens to have a refractive index similar to water, therefore they are very difficult to spot from an aqueous sample. To solve th is problem, biological stains are added so that microorganisms can be visualized. Stains are classified as either simple or differential.Simple stains impart the same color to all structures whereas differential stains contain more than one dye and impart different colors to various structures(Delost, 39). One very important method is the Gram Stain, which was first introduced by Hans Christian Gram in the late 1800s. It has been modified and set numerous times. The Gram stain will differentiate gram-positive bacteria from gram-negative bacteria (Delost, 39). Gram stain is one form of a differential stain that is widely even in the methods.It consists of several(prenominal) reagents such as crystal violet, Grams iodine, ethyl alcohol or acetone, and safranin O or carbulfuchsin. Bibliography Unknown. (2000). Bacteria Life History and Ecology. Retrieved on February 18, 2007 from the Berkeley Free Clinic website http//www. ucmp. berkeley. edu/bacteria/bacterialh. html Unkown. (2006). Bacteria. Retrieved on February 18, 2007 from the Users. rcn. com website http//users. rcn. com/jkimball. ma. ultranet/BiologyPages/E/Eubacteria. Delost, M. Introduction to Diagnostic Microbiology. (1997). Harcourt Brace & Company Asia Pte Ltd. .