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  1. Odotan edelleen. Vai voidaanko hiljaisuus tulkita myöntymisen merkiksi?
  2. Totta :)
  3. "Keskustelun lopettaminen sopii minulle hyvin, sillä en usko että mikään taho osaa esittää merkittävää uutta tutkimustietoa tästä kysymyksestä."

    Yritetään nyt vielä.

    "The endospore consists of the bacterium's DNA and part of its cytoplasm, surrounded by a very tough outer coating.

    Endospores can survive without nutrients. They are resistant to ultraviolet radiation, desiccation, high temperature, extreme freezing and chemical disinfectants. According to scientist Dr. Steinn Sigurdsson, "There are viable bacterial spores that have been found that are 40 million years old on Earth - and we know they're very hardened to radiation."[4] Common anti-bacterial agents that work by destroying vegetative cell walls do not affect endospores. Endospores are commonly found in soil and water, where they may survive for long periods of time."

    "Endospores are refractile - light cannot penetrate them - so that they are very easy to see in the phase microscope and this makes it easy to detect them. Most endospores have no measurable metabolism and are really a form of suspended animation. Endospores can survive for a very long time, and then return to a growing state, a process termed germination. Endospores that were dormant for thousands of years in the great tombs of the Egyptian Pharaohs were able to germinate and grow when placed in appropriate medium. Several scientists have been able to recover viable endospores from bees trapped in amber that is 25-40 million years old. The microbe isolated was found to be most closely related to Bacillus sphaericus. There are even claims of endospores that are over 250 million years old being able to germinate when placed in appropriate medium, but these claims still need to be verified."

    "The core is surrounded by a tough and highly impermeable coating that is made up of several layers. Endospores serve to protect the bacterium from harmful environmental conditions by reducing it into a desiccated, cryptobiotic and highly defensive state which conveys resistance to many environmental conditions that would otherwise harm and kill the vegetative form of the bacterium. These environmental conditions include extreme temperatures, radiation, extreme pH levels, extreme pressures and harmful chemical agents [1]. The metabolic dormancy and protective capability of endospores were demonstrated by the successful isolation and revival of Bacillus sp. endospores from 25- to 40-million-year-old amber"

    "Heat Resistance

    Wet heat resistance is a notable characteristic of spores when suspended in an aqueous medium. Generally, wet heat resistance allows spores to be resistant to temperatures 40 degrees celsius higher than their respective vegetative form [11]. The major determinant of wet heat resistance is the core water content [10]. Spores exhibit an inversely proportional relationship between water content and wet heat resistance and thus, spores with increased wet heat resistance have decreased core water content [10]. In addition, spores that form at higher temperatures will naturally have lower core water content, and thus, have greater wet heat resistance [11]. Dry heat causes significant DNA damage in a vegetative cell [11]. As a result, SASPs play a major role in the dry heat resistance of spores. By binding to and physically shielding the DNA, SASPs prevent its breakage at increased temperatures [10] [11].

    Chemical Resistance

    Many harmful chemicals kill bacteria via DNA-damaging mechanisms [10]. However, spores have evolved a number of mechanisms that confer chemical resistance. The spore coat is important in the resistance to many oxidizing chemicals such as chlorine dioxide, hypochlorite, ozone and peroxynitrite [2] [10] [11]. It functions by reacting with these chemical agents and detoxifying them before they pass through the spore coat [10]. In addition, the inner membrane’s extremely low permeability prevents both hydrophobic and hydrophilic molecules from entering into the core [11]. SASPs also protect the DNA by binding to it and shielding it from harmful chemical agents that enter the core [11].

    UV Radiation Resistance

    UV radiation damages the DNA of a cell and induces mutations. Saturation of an endospore’s DNA with SASPs protects the DNA from this harmful threat "

    Phaoittelen, etten jaksanut kääntää tekstejä, mutta olet osoittanut ymmärtäväsi englantia.

    "Solonia on arvostettava sekä tässä että monessa muussa keskustelussa laajasta tietämyksestä, asiassa pysymisestä ja vain harvoin henkilökohtaisuuksiin menosta"

    Kiitos itsellesi siitä, että olet piristävä poikkeus normaaliin palstalla nähtävään asiattomaan jankkaukseen.

    http://microbewiki.kenyon.edu/index.php/Bacterial_endospores

    http://www.microbiologytext.com/index.php?module=book&func=displayarticle&art_id=69

    http://en.wikipedia.org/wiki/Endospore
  4. Nuo Mauno Peltosen vanhat ja väsyneet raapustukset on kumottu palstalla jo kymmeniä kertoja. En jaksa vaivautua uudelleen, joten etsikää haulla.
  5. Järkytyin itsekkin :)