Microbiology Question

Discussion in 'Pre-Medical - MD' started by NubianPrincess, Oct 21, 2002.

  1. NubianPrincess

    NubianPrincess Perpetually Bored

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    I was wondering...
    An obligate anaerobe is killed by the presence of oxygen. Will they die immediately, or are they able to produce spores...before they die...since the spores can still exist in the presence of oxygen?
     
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  3. They would die pretty quickly, just like us (oblgate aerobes) would die quick in the absence of Oxygen. The bacterial cells would not be able to make a spore fast enough( remember only Gram + cells can even makes spores).

    Hope that helps. Micro's my major. :)
     
  4. Winston Smith

    Winston Smith i didn't do it

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    hey. I'm taking microbio right now too.

    My answer is obviously from limited knowledge but I would say no on the basis that bacteria produce spores ONLY when nutrients are insufficient to them and NOT under conditions of stress/heat/resistance, etc. I don't think the presence of oxygen is an example of when nutrients are insufficient.
     
  5. Dreamin

    Dreamin Senior Member

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    I'm a microbiology major and I just had a lecture today about this topic. Obligate anaerobes will definately die in the prescence of oxygen (facultative anaerobes are the ones that can survive in the prescence of oxygen, but prefer an environment without oxygen). It takes about 8hrs for a cell to sporulate...so the cells would die. Cells mostly sporulate under extreme heat or low nutrient concentrations. I know, I'm a dork for knowing this.
    Hope this helps!
     
  6. NubianPrincess

    NubianPrincess Perpetually Bored

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    Cool, microbio majors. Now I know where to come when I have a question :) :clap: :D
     
  7. Joe Joe on da Radio

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  8. geromine

    geromine Senior Member

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    If the process of of sporulation is complete before moving the obligate anaerobe into aerobic conditions, the bacteria will survive since in dormant form, it is metabolically inert and thus will not be producing any toxic oxygen species.
    However if placed under aerobic conditions before sporulation begins, it is less likely to survive since metabolic bioproducts of oxygen are toxic to the non-dormant organism.
    In sporulation, it is always a question of percent survival. Even if most of the bacteria die but a few that are somehow sheltered from o2 are able to form spores, sporulation has been successful in ensuring species survival.
     
  9. uclachris

    uclachris Doctor Doctor Member

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    I want to be a micro major... that's so cool!!! An friend of mine was a micro major and she knew all this...

    Now I can tell you how to use bragg's law to determine the position of an atom in a crystallography experiment... ohhh... useful.... Not really (unless I go to radiology)...

    C
     
  10. rjhtamu

    rjhtamu Stargazer Royale

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    Another micro major here, but I won't add to what's been said, they pretty much covered it.
     
  11. tabbycat

    tabbycat Junior Member

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    Hello, UK micro person joining in.
    All the answers are correct, but Geromime is closest to the truth. The cells will only produce spores under nutrient-deficient conditions, but a heterogenous population is created containing a mixture of vegetative cells and spores.
    Thus when the population is exposed to oxygen, the vegetative cells will die off, but there will be some spores present, and of course these are not oxygen sensitive.
    And to confuse the issue, vegetative cell survival depends on the immediate surrounding environment - there may well be potential for microenvironments which are anaerobic in which cells can survive, this is particularly true for food samples.
     
  12. gooloogooloo

    gooloogooloo Senior Member

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    sorry that i want to borrow your thread, but i don't think that my thought is worth a whole new thread for it.
    today i got back my biochem midterm and i got a high F. i was deeply shock. i studied it so fxxxing hard and i know that i am smarter than a lot of people in my class, i just cannot believe that i got such a grade. in fact, i doubt that i am now depressed. well, i am not really depressed from one single test, but rather several events in my life.... the law suit, my class, gpa, family issue, debt and relationship... premed process is a stressful one so the weak could be weeded out before they enter the demanding field of medicine... i am feeling been weeded out right now.... i am so angry at myself. this is my second time taking biochem (withdrew the first time) yet i cannot fxxxing master it! WTF WTF WTF WTF WTF i was shooting for an A in that course, not the most i could get is probably as B+
    WTF WTF WTF WTF WTF
    I wonder if there is any biochem major?
     
  13. uclachris

    uclachris Doctor Doctor Member

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    Biochem here...

    that reminds me of my first o-chem final in 2nd quarter honors ochem... I got the lowest grade of the class (21%) even though the night before the TA commented at the review session that the best prepared person was me! I just studied my butt off and got better grades (Like As) for the other MTs and Final... It's possible...

    Ended up with a low A in the class.


    Good Luck
     

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