You inoculate two tubes of liquid culture medium with 100 bacterial cells and incubate one tube at 37°C and the other at 55°C. After 48 hours, there are 20,000 bacteria per milliliter in the 37°C tube and 1,568,000 bacteria per milliliter in the 55°C tube. You conclude that this species is a .

thermophile.

Explanation:

A thermophile is a kind of bacteria that belongs to the Archaea Domain and they are the kind of animals that can live in a region of high or extreme temperature. There has been a research on a kind of thermophile which is known as Methanopyrus kandleri which can exist in an extreme temperature of up to 500° C.

So, if we take a look at the question again we can see that after 48 hours and at 37°C 20,000 bacteria per milliliter are already in the tube and at more higher temperature of 55°C we have 1,568,000 bacteria per milliliter which means that at higher temperature more of the bacterial is produced.