Your
freezer doesn't kill germs like high temperatures in an oven does, it
only slows down their metabolism so the reproduce more slowly. One of
the the reasons germs are a hazard is because they manufacture toxins as
waste products. Therefore, even cooking food at normal temperatures
that has "gone off", while killing the germs, doesn't necessarily render
those toxins harmless. If you've ever put tomatoes or other watery food
in a freezer, you'll know that they become mushy when thawed. That's
because all living things are built from cells, just like Lego. The
cells are like capsules of water which burst when water expands on
freezing, causing a loss of structural integrity and limpness in a fruit
such as a tomato (Is it a fruit or veg? That's another argument!).
Half-hardy flowers such as petunias are damaged by frost for the same
reason, but hardy flowers have "anti-freeze" in their cells. This
prevents the cellular fluid from freezing at low temperatures, so the
plants can withstand severe frosts. Possibly this is the mechanism by
which this worm survived 46,000 years in permafrost, having evolved and
achieved this survival technique.
Nematodes. Image courtesy CSIRO, CC BY-SA 3.0 via Wikimedia Commons.
