The bacteria-containing genes required for degrading oil were located on plasmids.
Plasmids are small DNA molecules most commonly found in bacteria.
Although at the time of the invention several species of oil-metabolizing bacteria were known to exist, the bacteria were not efficient in degrading the oil, for example, that accumulated as the result of an oil spill, either when used alone or in combination with the other oil-metabolizing bacteria.
Although it was recognized that the use of more than one type of oil-producing bacterium would improve the efficiency of the oil-breakdown process, the bacteria competed with each other, thereby limiting their applicability.
The claims for gene nucleotide sequences included claims for complementary DNA exons in the BRAC1 and BRAC2 genes.