Bacteria and Growth Temperature

INTRODUCTION The environments of Earth include conditions in which physical and chemical extremes make it very difficult for organisms to break down. Conditions that can destroy a raging cells and biomolecules include high and low temperatures low amounts of type O and pissing and high levels of salinity, acidity, alkalinity, and radiation. Examples of extreme environments on Earth are genus Oestr functiond geysers and oceanic thermal vents, polar ocean ice, and oxygen-depleted rivers and lakes. Organisms that have evolved special adaptations that permit them to live in extreme conditions are called extremophiles. Photo by Dmitry Pichugin Thermophiles are microorganisms with optimal exploitation temperatures between 60 and 108 degrees Celsius, isolated from a number of marine and terrestrial geothermally-heated habitats including shallow terrestrial hot springs, hydrothermal vent systems, sediment from volcanic islands, and deep sea hydrothermal vents. -Encyclopedia of Environ mental Microbiology, 2002. vol. 3. Temperature and bacterium The lowest temperature at which a particular species will obtain is the minimum change by reversalth temperature, while the maximum winth temperature is the highest temperature at which they will grow.The temperature at which their growth is optimal is called the optimum growth temperature. In general, the maximum and minimum growth temperatures of any particular type of bacteria are roughly 30F (-1C) apart. just about bacteria thrive at temperatures at or around that of the human body 98. 6F (37C), and nigh, such as Escherichia coli, are usual parts of the human intestinal flora. These organisms are mesophiles (moderate-temperature-loving), with an optimum growth temperature between 77F (25C) and 104F (40C).Mesophiles have adapted to thrive in temperatures blotto to that of their host. Psychrophiles, which prefer dusty temperatures, are divided into two groups. One group has an optimal growth temperature of abo ut 59F (15C), but can grow at temperatures as low as 32F (0C). These organisms live in ocean depths or Arctic regions. Other psychrophiles that can also grow at 32F (0C) have an optimal growth temperature between 68F (20C) and 86F (30C). These organisms, sometimes called psychrotrophs, are often those associated with nutrient spoilage under refrigeration.Thermophiles thrive in very hot environments, many having an optimum growth temperature between 122F (50C) and 140F (60C), similar to that of hot springs in Yellowstone National Park. Such organisms thrive in compost piles, where temperatures can rise as high as 140F (60C). Extreme thermophiles grow at temperatures above 195F (91C). Along the sides of hydrothermal vents on the ocean bottom 217 mi (350 km) north of the Galapagos Islands, for example, bacteria grow in temperatures that can reach 662F (350C). pH and bacteriaLike temperature, pH also plays a role in determining the ability of bacteria to grow or thrive in particular en vironments. Most commonly, bacteria grow optimally within a narrow range of pH between 6. 7 and 7. 5. Acidophiles, however, prefer acidic conditions. For example, Thiobacillus ferrooxidans, which occurs in drainage water from coal mines, can survive at pH 1. Other bacteria, such as Vibrio cholera, the cause of cholera, can thrive at a pH as high as 9. 0. Osmotic pressure and bacteria Osmotic pressure is another limiting factor in the growth of bacteria.Bacteria are about 80-90% water they require moisture to grow because they obtain most of their nutrients from their aqueous environment. Examples of Extreme Communities Deep Sea. The deep sea environment has high pressure and unheated temperatures (1 to 2 degrees Celsius 33. 8 to 35. 6 degrees Fahrenheit), except in the vicinity of hydrothermal vents, which are a part of the sea floor that is spreading, creating cracks in the earths crust that release heat and chemicals into the deep sea environment and create underwater geysers.In these vents, the temperature may be as high as 400 degrees Celsius (752 degrees Fahrenheit), but water remains unstable owing to the high pressure. Hydrothermal vents have a pH range from about 3 to 8 and unusual chemistry. In 1977, the submarine Alvin found life 2. 6 kilometers (1. 6 miles) deep near vents along the East Pacific Rise. Life forms ranged from microbes to invertebrates that were adapted to these extreme conditions. Deep sea environments are home to psychrophiles (organisms that like cold temperatures), hyperthermophiles (organisms that like very high temperatures), and piezophiles (organisms adapted to high pressures).Hypersaline Environments. Hypersaline environments are high in salt concentration and include salt flats, evaporation ponds, natural lakes (for example, owing(p) Salt Lake), and deep sea hypersaline basins. Communities living in these environments are often dominated by halophilic (salt-loving) organisms, including bacteria, algae, diatoms, and protozo a. There are also halophilic yeasts and other fungi, but these normally cannot tolerate environments as saline as other tax. Deserts. Deserts can be hot or cold, but they are always dry.The Atacoma desert in Chile is one of the oldest, driest hot deserts, sometimes existing for decades without any precipitation at all. The coldest, driest places are the Antarctic Dry Valleys, where primary inhabitants are cyanobacteria, algae, and fungi that live a few millimeters at a lower place the sandstone rock surface. Although these endolithic (living in rocks) communities are based on photosynthesis, the organisms have had to adapt to long periods of darkness and extremely dry conditions.Light dustings of blast that may melt in the Antarctic summer are often the only sources of water for these organisms. Ice. Permafrost, and Snow. From high-altitude glaciers, often colored pink from red-colored algae, to the polar permafrost, life has evolved to use frozen water as a habitat. In some insta nces, the organisms, such as bacteria, protozoa, and algae, are actually living in liquid brine (very zesty water) that is contained in pockets of the ice. In other cases, microorganisms found living on or in ice are not so much ice lovers as much as ice survivors.These organisms may have been trapped in the ice and simply possessed sufficient adaptations to enable them to persist. Atmosphere. The ability for an organism to survive in the atmosphere depends greatly on its ability to withstand desiccation and exposure to ultraviolet radiation. Although microorganisms can be found in the upper layers of the atmosphere, it is unclear whether these constitute a functional ecosystem or simply an aerial suspension of live but largely inactive organisms and their spores. Outer Space.The study of extremeophiles and the ability of some to survive exposure to the conditions of outer space has raised the possibility that life might be found elsewhere in the universe and the possibility that easy life forms may be capable of traveling through space, for example from one planet to another. Research Findings freshfound gene may help bacteria survive in extreme environments Resulting microbial lipids may also signify oxygen dips in Earths history. Jennifer Chu, MIT News Office July 26, 2012 A new discovered gene in bacteria may help microbes survive in low-oxygen environments.A bacterial cell with the gene, left, exhibits protective membranes. A cell without the gene, right, produces no membranes. scene Paula Welander In the days following the 2010 Deepwater Horizon oil spill, methane-eating bacteria bloomed in the Gulf of Mexico, feasting on the methane that gushed, along with oil, from the damaged well. The sudden influx of microbes was a scientific curiosity Prior to the oil spill, scientists had observed relatively few signs of methane-eating microbes in the area. Now researchers at MIT have discovered a bacterial gene that may explain this sudden influx of methane- eating bacteria.This gene enables bacteria to survive in extreme, oxygen-depleted environments, lying dormant until food such as methane from an oil spill, and the oxygen needed to metabolize it become available. The gene codes for a protein, named HpnR, that is responsible for producing bacterial lipids known as 3-methylhopanoids. The researchers say producing these lipids may better prepare nutrient-starved microbes to make a sudden appearance in nature when conditions are favorable, such as after the Deepwater Horizon accident.The lipid produced by the HpnR protein may also be use as a biomarker, or a signature in rock layers, to identify dramatic changes in oxygen levels over the course of geologic history. The function that interests us is that this could be a window into the geologic past, says MIT Department of Earth, Atmospheric and Planetary Sciences (EAPS) postdoc Paula Welander, who led the research. In the geologic record, many millions of years ago, we bring out a num ber of mass extinction events where there is also evidence of oxygen depletion in the ocean.Its at these key events, and immediately afterward, where we also suppose increases in all these biomarkers as well as indicators of climate disturbance. It seems to be part of a syndrome of warming, ocean deoxygenation and biotic extinction. The ultimate causes are unknown. Welander and EAPS Professor Roger command have published their results this week in the Proceedings of the National Academy of Sciences. This image shows that 5 different extreme environments that the extremeophile live. Such as, Sea Vennts at sea floor, Yellowstone Hotsprings, Antartica Subglacial Lakes, at Atacama Desert, and lastly at Jupiter (Space).Europa is one of Jupiters moons, and is covered in ice. Scientists have recently uncovered strong evidence of liquid water beneath Europas ice, which may be due to hydrothermal vents, which may in turn host bacteria. Credit Nicolle Rager Fuller, NSF REFFERENCES 1. http// science. jrank. org/pages/714/Bacteria. htmlixzz28JlGDpue 2. Horikoshi, K. , and W. D. Grant. Extremophiles Microbial Life in Extreme Environments. New York Wiley-Liss, 1998. 3. Madigan, M. T. , and B. L. Marrs. Extremophiles. Scientific American 276, no. 4 (1997) 8287. 4.Rothschild, L. J. , and R. L. Mancinelli. Life in Extreme Environments. Nature 409 (2001) 10921101. 5. Seckbach, J. , ed. Journey to Diverse Microbial Worlds Adaptation to Exotic Environments. Dordrecht, Netherlands Kluwer schoolman Publishers, 2000. 6. http//www. biologyreference. com/Ep-Fl/Extreme-Communities. htmlbixzz28Jn5EptD 7. http//www. nsf. gov/news/special_reports/sfs/index. jsp? id=lifesid=ext ASSIGNMENT 1 BACTERIAS THAT LIVE IN EXTREAM ENVIRONMENT NAME SARANKUMAR PERUMALU MATRIX NO 4112033021 LECTURER MR MOOHAMAD ROPANING SULONG