2.5. Cell surface hydrophobicity determination
Cell surface hydrophobicity of Bacillus sp. USTBa was accessed
by the bacterial adhesion to hydrocarbons (BATH) assay [24].
Briefly, strain USTBa was grown in 30 mL MSM containing 2% (w/
v) crude oil for 2 weeks in an orbital shaker at 35 C and
180 rpm. Cells were harvested by centrifugation at 5000g for
15 min and re-suspended in sterile MSM. Subsequently, an aliquot
of 500 lL crude oil was added to the 5.0 mL microbial cell suspension
and vortexed for 2 min. The OD at 600 nm (A600) was taken.
BATH expressed as cell adherence (%) to crude oil is calculated as
follows:
BATH ¼ f1 ðA600 of the aqueous phase=A600 of the initial
cell suspensionÞg 100