Bacteria are ubiquitous prokaryotes, i.e., they occur anywhere and everywhere, in water, in air, in soil, in all living organisms except the pits of volcanoes, deep strata of rocks, tops of high mountains and
blood of healthy animals. Some thermophilic bacteria can withstand the temperature upto 78°C
DNA Packaging in Prokaryotes. In prokaryotes, such as E. coli though they do not have a specified nucleus, the DNA is not dispersed throughout the cell. DNA (being negatively charged) is held with some nucleoid-associated proteins (NAPs, which have positive charges) in a 'nucleoid' region. The DNA in nucleoid is arranged in big loops supported by proteins.