Two strains of hydrocarbon-utilizing bacteria were isolated
from soil samples of the Kuwait Burqan oil field at a temperature
of 37°C. The bacteria were motile endospore-forming
rods with slight differences in their metabolic patterns and 16S
rRNA sequence. Vegetative cells of the strains designated as
AHI and AHII had an ultrastructure typical of Gram-positive
bacteria and showed Gram-positive staining. The bacteria did
not show pigmentation. Best growth was observed at 37°C at
neutral pH and NaCl concentrations in the range of 5-10 g per
I. Both strains were obligatory aerobic and developed on synthetic
media with either Diesel fuel, n-decan or naphthalene as
the sole carbon and energy source. No specific growth factors
were required. On the basis of their morphological, physiological
and biochemical features, as well as their 16S rRNA
analysis and electron microscope study, both strains were
assigned to the species of Bacillus subtilis.