[lara (OP)]

can any1 tell me of the microbicidal action of mushrooms??plz, it's urgent!!!!

[Rokitansky]

Many fungi, and bacteria as well, produce chemical substances that have adverse effects on other microorganisms. Penicillin was discovered that way.

[nilmot]

Mushroom as inthe fugual species or mushroom as in the fruiting body?

As a fungal species: when the surrounding envirionment is harsh or the competition for food/space is limited, anti-fungal or anti-bacterial agents will be secreted by the fungus to eliminate the competition.

Ususally it's the anti-bacterial effect that's more well known and put into use by humans. The modes of action of anti-bacterial agents are to affect the:

Prokaryote ribosomes - 70S ribosome is distinctive in bacteria, prevent protein/enzyme synthesis

DNA synthesis - either by direct breakdown of bacterial DNA or inhibiting enzyme required for DNA synthesis.

Cell wall degradation - breakdown/prevent synthesis of bacterial cell wall, by preventing peptidoglycan being synthesized, bacteria die becuase they have lost the ability to maintain osmotic pressure.

These are the common ones, there are many other way for antibiotic to act on microbes.

Tom