Two bacterial species were successfully isolated, namely AL1 from Angsi light crude oil and KH1 from Khefji heavy crude oil. The results from sequencing showed that the isolate AL1 has 97% sequence match with Acinetobacter baumannii, whereas the isolate KH1 has 98% similarity to DNA sequences of Pseudomonas aeruginosa. Both bacterial species were able to degrade Angsi light crude oil 100% within seven days. However, only P. aeruginosa completed the degradation of Khefji heavy crude oil. A. baumannii only degraded 67% of the Khefji heavy crude oil. Discussion of the results suggested that P. aeruginosa that originated from the Khefji heavy crude oil has less metabolic restriction (eg. biosurfactant secretion and quorum sensing), which allows the bacteria to degrade hydrophobic hydrocarbons predominantly found only in high density crude oil. This advantageous characteristic was not naturally found in A. baumannii that was isolated from Angsi light crude oil.