Bacterium: some maybe but maybe not.
Where I am coming from here is that during my very first "algae fighting episode" I initially rinsed my very, very fine mechanical media in tap water and "let it sun on the back porch for periods of generally over two weeks (please note that I have tons of very fine mechanical media, 50Mu and 100Mu, and the back porch would be partially covered with 15 to 20 of these media pads)".
When I ceased the procedure cited above and began soaking the media in a mild chlorine solution "I believe" that I could tell a noticeable difference in the algae removal from the tank water.
If algae can survive in sunlight in this fine mechanical filtration media which appears to be very dry media for a period of two weeks then IMHO a bacterium (although not necessarily all types) can also.
Virus: a few maybe but generally not.
Viral pathogens are "nasty little devils".
Virus can remain dormant in surficial soils (IMHO as well as many other environments) for periods which are known to be at least 21 years prior to infection of a host cell.
Hence my previous question concerning chlorine concentration and chlorine contact times with respect to viral disinfection.