Introduction
Most organisms on earth are able to live in their habitat under certain conditions. Others are able to live under very extreme conditions like extreme temperatures, pH, salinity, pressure and radiation just to name a few. These organisms are called extremophiles and they are polyphyletic. According to (Singh et al. 2011), microorganisms, but specifically bacteria are especially well adapted for surviving extreme conditions. Lately scientists have become very intrigued by extremophiles because of their biotechnological and commercial value to humans. Scientists are still at the beginning stages of being able to understand these organisms since very little research has been done on extremophiles prior to the current interest in them. The different categories of extremophiles will be discussed in this paper as well as a few examples of extremophiles and also what value those extremophiles add to the human existence.
Types of extremophiles
There are 14 categories of extremophiles according to Horikoshi et al. (2010). They are:
• Acidophiles which are organisms that can withstand very acidic environments below a pH of 4.
• Alkaliphiles are at the opposite of the spectrum being organisms that are able to live in very alkaline environments with pH values exceeding 10.
• The types of organisms that can survive inside rocks are endoliths which is another type of extremophile. Halophiles are organisms that love saline environments and they need a concentration of at least 1M of salt to grow.
• Hyperthermophiles can withstand very high temperatures up to 800C.
• Organisms that can live at extremely low temperatures on rocks are hypoliths.
• There are also those organisms that are able to overcome high levels of heavy metal...
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...ophiles occupy are so extreme that it can also be remote and therefore not the types of areas that humans would generally occupy. These range from volcanically active areas, to the icy regions of the poles and very high mountains (Horikoshi et al. 2010). Nevertheless we must continue the search.
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The Artemia franciscana can survive in extreme conditions of salinity, water depth, and temperature (Biology 108 laboratory manual, 2010), but do A. franciscana prefer these conditions or do they simply cope with their surroundings? This experiment explored the extent of the A. franciscanas preference towards three major stimuli: light, temperature, and acidity. A. franciscana are able to endure extreme temperature ranges from 6 ̊ C to 40 ̊ C, however since their optimal temperature for breeding is about room temperature it can be inferred that the A. franciscana will prefer this over other temperatures (Al Dhaheri and Drew, 2003). This is much the same in regards to acidity as Artemia franciscana, in general thrive in saline lakes, can survive pH ranges between 7 and 10 with 8 being ideal for cysts(eggs) to hatch (Al Dhaheri and Drew, 2003). Based on this fact alone the tested A. franciscana should show preference to higher pH levels. In nature A. franciscana feed by scraping food, such as algae, of rocks and can be classified as a bottom feeder; with this said, A. franciscana are usually located in shallow waters. In respect to the preference of light intensity, A. franciscana can be hypothesized to respond to light erratically (Fox, 2001; Al Dhaheri and Drew, 2003). Using these predictions, and the results of the experimentation on the A. franciscana and stimuli, we will be able to determine their preference towards light, temperature, and pH.
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Since Woese’s research, Archaea have been divided into two main phyla, the Eutyarchota and Crenarchaeota, with the majority being extremophiles. This supports the hypothesis that Eubacteria and Archaea had a thermophilic common ancestor that was able to tolerate the hot conditions on Earth. Nelson et al (1999) also found that Thermotoga maritima bacteria had 24% genes of archaeal origin when analysed, supporting the theory of Thermatoga’s early branching from Archaea in the Tree of Life.
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Bacterial growth may be controlled by many methods; the techniques relevant to this experiment include heat, ultraviolet (UV) light, and antimicrobial control. Using heat as a means of controlling bacterial growth is favorable because it is quick, safe, and cost-effective (Nester, 2007). There are two kinds of heat: moist heat, which destroys the proteins of microorganisms by boiling or steaming, and dry heat, which requires high temperatures to oxidize cell components and damage proteins by incineration or dry heat ovens (Nester, 2007). Cellular proteins are essential in carrying out important biological activities, so without them, the bacteria will not be able to survive (Nester, 2007). Moist heat is widely used to treat drinking water,
The existence of Cyanobacteria is of vital importance to all life on planet earth. The process by which the amospehere of planet earth changed, from its early atmosphere to what it is present day is due to the process of photosynthesis, which is originated in a Cyanobacterium. Oxygenic photosynthesis is what made Cyanobacteria unique among the early organisms on planet earth whereby it used Carbon dioxide from the atmospehere and water as an electron donor to produce carbohydrates, releasing oxygen as a byproduct. In comparison, other early organisms on planet earth produced energy via
Rastogi, G. and Sani, R.K. (2011) 'Chapter 2 :Molecular Techniques to Assess Microbial Community Structure, Function, and Dynamics in the Environment', in Ahmad, I., Ahmad, F. and Pichtel, J. (ed.)Microbes and Microbial Technology. California, USA: Springer Science, pp. 29-57.
All living things are made up of enzymes and proteins that break down when the organism is exposed to extreme life threatening conditions (visualinsight.net). Extremophiles are believed to have adapted to these extreme conditions because of “heat stress proteins.” Scientists have discovered special molecules, also known as “molecular chaperons,” that are produced when the organism is exposed to deadly conditions. These molecules are activated and will repair the proteins damaged by stressful encounters in the same way a human will develop a fever to fight off infection. The fever activates these “savior proteins” and healing
The protozoan commonly known as the “water bear” is an extremophile that has engaged many in the scientific community. The Tardigrade is an invertebrate that has eight legs and comes in many shapes and sizes. This group has many adaptations such as cryptobiosis that allows it to survive in extreme environments. The Tardigrade can be found from land, to water, to sulfur springs, and to over 25 species found in the frozen tundra of Antarctica (Miller et al, 2001). To understand these creatures this paper will summarize the taxonomy, reproduction, food, and protective genetics, of the Tardigrades. The first section to this paper will examine is how these creatures are divided taxonomically.
Osmosis is an animal’s way of adapting to different types of salinities (Office of Naval Research 3). All marine mammals have special traits that they adapted to help them survive in or around marine habitats (Marietta College 1). As prompted by the Marietta College of Ohio “Many organisms in saltwater are osmoconformers.” (1). An osmoconformer is an organism that has the same concentration of salt within its body as the surrounding water (1)....
Every organism requires a specific environment in order to survive. Bacteria alike, different types of bacteria are able to survive and reproduce in different types of environment. Some factors that affect the growth of bacteria include temperature, presence of certain gases and pH of the medium it is in.