Andreas Toba andreas at
Thu Mar 16 22:19:51 EST 2000

thanks for your quick answer

I think 99,99 % of the natural ocurring bacteria has, at least, one plasmid.
Even more if the environment is so extreme like a contaminated lake.
Plasmids are not essential but they encode for great advantge. On of those
is Resistance to extreme condition. There is enough evidence of shearing
resistance mechanism between to very different bacteria. How's this? three
possible answers:
-Plasmids, or

Maybe the resistance is in the chromosome, but is posible (and would be the
logic secuence of events) those genes jump across genera using the three
"cars" mentioned above, mixing with chromosome and/or steping out of the
chromosome, kidnaping crucial new genes to spread among the other bacteria.

In a hostile environment, full of heavy metals, not-degradated antibiotics
the most preciuos genes are those that encode for multiresistance, so only
those bacterias that can pick up one or all of the "cars" will survive.

Once again Thanks for your quick response, and excuse my english

Let's keep talking

Andreas Toba (undergraduated Cell Biology student)

PD: I'd appreciate any tip or info about how to work with natural bacteria,
isolate their plasmids, conjugation or transformation

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