How big is the E coli genome?
|E. coli O157:H7||5.44 x 106||5,416|
|Pseudomonas aeruginosa||6.3 x 106||5,570|
Thus, the thousandfold greater size of the human genome compared to that of E. coli is not due solely to a larger number of human genes. The human genome is thought to contain approximately 100,000 genes—only about 25 times more than E. coli has.
- Sequencing the first human genome cost about $1 billion and took 13 years to complete; today it costs about $3,000 to $5000 and takes just one to two days.
- 3 billion
- In genetics, the gene density of an organism's genome is the ratio of the number of genes per number of base pairs, usually written in terms of a million base pairs, or megabase (Mb). The human genome has a gene density of 12-15 genes/Mb, while the genome of the C. elegans roundworm is estimated to have 200.
Bacterial genome. Bacterial genomes are generally smaller and less variant in size among species when compared with genomes of animals and single cell eukaryotes. Bacterial genomes can range in size anywhere from about 130 kbp to over 14 Mbp.
- Most bacteria have one or two circular chromosomes. Humans, along with other animals and plants, have linear chromosomes that are arranged in pairs within the nucleus of the cell.
- Genome sizes are typically given as gametic nuclear DNA contents ('C-values') either in units of mass (picograms, where 1 pg = 10−12 g) or in number of base pairs (in eukaryotes, most often in megabases, where 1 Mb = 106 bases). These are directly interconvertible as 1 pg = 978 Mb (or 1 Mb = 1.022 × 10−3 pg) (7).
- The earliest direct estimates of the size of human genome clustered around 3,000 Mb (megabase pairs) or 3.0 ×109 bp (base pairs). The textbooks settled on about 3,200 Mb based mostly on reassociation kinetics.
As you know eucaryotic cells contain a very large quantity of DNA (human cells have at least a thousand times more DNA than a typical bacteria cell). E.coli chromosomes have about 4.7 x 106 base pairs which results in a length of 1.6 mm. An E.coli cell, however is only 0.002 mm long .
- As you know eucaryotic cells contain a very large quantity of DNA (human cells have at least a thousand times more DNA than a typical bacteria cell). E.coli chromosomes have about 4.7 x 106 base pairs which results in a length of 1.6 mm. An E.coli cell, however is only 0.002 mm long .
- Doctors typically treat UTIs with a wide range of different antibiotics, such as ciprofloxacin (Cipro) and trimethoprim-sulfamethoxazole (Bactrim). However, some strains of E. coli, called extended-spectrum beta-lactamase (ESBL) E. coli, are resistant to most antibiotic treatments.
- Escherichia coli is a rod-shaped bacterium. Each bacterium measures approximately 0.5 μm in width by 2 μm in length. E. coli is a Gram-negative bacterium. E. coli cells stain Gram negative because they have a thin cell wall with only 1 to 2 layers of peptidoglycan.
Updated: 3rd December 2019