Helicobacter pylorii

Hi,
the Helicobacter pylorii changes its form between spiral and coccoid
one depending on enviromental condition
http://www.sodbrennen-welt.de/science/1994/1994_7524304.htm.

This helps the bacter to survive but I don't understand why, what are the
advantages in changing the form? How does it happens biochemically?

Any suggestion?

Thank you,
Fabrizio




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