Bacteria with reduced genome
The present invention provides a bacterium having a genome that is genetically engineered to be at least 2 to 14% smaller than the genome of its native parent strain. A bacterium with a smaller genome can produce a commercial product more efficiently. The present invention also provides methods for deleting genes and other DNA sequences from a bacterial genome. The methods provide precise deletions and seldom introduces mutations to the genomic DNA sequences around the deletion sites. Thus, the methods can be used to generate a series of deletions in a bacterium without increasing the possibility of undesired homologous recombination within the genome. In addition, some of the methods provided by the present invention can also be used for replacing a region of a bacterial genome with a desired DNA sequence.
1. An isolated E. coli bacterium having a genome that is between 4.27 Mb and 4.00 Mb, wherein the genome of the bacterium is lacking DNA selected from the group consisting of a flagella gene, a restriction modification system gene, a lipopolysaccharide surface synthetic gene, an insertion sequence element, an rhs element, a non-transcribed region in the genome of the native parent strain and a gene or other DNA sequence that is not present in both of any two bacteria strains of the same species of the native parent strain.
2. The isolated bacterium of claim 1 , wherein the genome does not comprise a scar.