Bacterial DNA is primarily compacted by supercoiling and folding. Briefly describe each mechanism. ...

Supercoiling refers to twisting of double-helical DNA such that the helix is twisted on itself. Supercoiling in the counterclockwise direction, opposite to the right-handed turn of DNA, is negative supercoiling, whereas twisting in the same direction as the helix is positive supercoiling. Negative supercoiling promotes unwinding of dsDNA, whereas positive supercoiling is thought to promote stability of dsDNA.
DNA is folded by small nucleoid-associated and structural maintenance of chromosomes (SMC) family proteins. Folding serves to condense the chromosome, which reduces the space within the cell that is taken up by the chromosome. Essentially, this compaction mechanism allows for a lot of DNA to be stored in a tiny cell