November 26, 2017 Sunday
Bedtime Story
From Hypothesis to Gathering Evidence
Even as late as the end of 2005, the role
of CRISPR/Cas system in conferring immunity to the microbes remained a
speculation or an educated guess at the best.
Strong evidence was still lacking.
The idea of the CRISPR’s role in immunity
was then at the stage of hypothesis or a theory.
Yet the material published in these three
papers of 2005 was enough to send other microbiology and genetics labs rolling
to seek out evidence for the hypothesis being proposed.
It did not take very long as the next major
work that provided the lacking evidence came out in March 2007 in the journal
Science.
The paper was titled “CRISPR provided
acquired resistance against viruses in prokaryotes” and had eight authors
namely Barrangou R, Fremaux C, Deveau H, Richards M, Boyaval P, Moineau S,
Romero DA and Horvath P.
Philippe Horvath was a Ph.D. student at the
University of Strasbourg which is the second largest university of France that
supports 4000 researchers besides 46,000 students.
He was broadly interested in food science
and was concentrating then on the genetics of a specific lactid-acid bacteria used
in the manufacturing of sauerkraut.
If you are not a European or not of
European descent you might not know what sauerkraut is; much like how a typical
European may have no knowledge or even taste for delicious Indian masala dosa (type
of thin crispy pancake made from fermented batter of rice and black gram) eaten
with chutney and sambar (lentil based vegetable stew spiced up with tamarind
broth).
Sauerkraut is essentially finely cut
cabbage that is pickled by lactic-acid fermentation.
It essentially is to Europeans what pickles
and spices are to South Asians.
The cabbage is finely shredded, salted and
left to ferment.
The cabbage thus left to ferment gets fully
fermented in three stages wherein the star of each stage is distinct bacteria.
The first stage of fermentation is carried
out by the anaerobes such as Klebsiella and Enterobacter.
Acid begins to form and pH gradually falls.
As the acidity increases, the environment
gets too hostile for many microbes and at this stage acid resistant microbes
take over.
The acid resistant microbe that maximally
drives fermentation at this stage is the Leuconostoc mesenteroides.
Finally in the third stage Lactobacillus
takes over and ferments any leftover sugars making the environment even more
acidic.
Lactobacillus is so remarkably resistant to
acid that they thrive well even in the harsh acidic environs of our gut and
female vagina and serve as useful commensals keeping out other microbes from
growing there.
Their biofilms form the lining of our innermost
and intimate parts.
Stay tuned to the voice of an average story storytelling
chimpanzee or login at http://panarrans.blogspot.com
Good night mon ami and my fellow cousin ape.
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Another great educator and a teacher that I am aware of is
Professor Subhashish Chattopadhyay in Bangalore, India.
While I narrate stories, Professor Subhashish an electronic
engineer and a former professor at BARC, does and teaches real mathematics and
physics.
He started the participation of Indian students at the
International Physics Olympiad.
Do visit him here:
All his books can be downloaded for free through this link:
For edutainment and English education of your children, I
recommend this large collection of Halloween Songs for Kids:
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