| Abstract |
During oil spills in the field or for laboratory incubation studies, different oil concentrations are often encountered
or applied, yet how initial oil concentration affects biodegradation rates of hydrocarbons and the development
of oil degraders remains unclear. We incubated seawater for 50 d with different oil concentrations (0, 50,
100, 200, 400 and 800 ppm). n-Alkanes and polycyclic aromatic hydrocarbons (PAHs), and the bacterial community
were analyzed periodically. Results show that the biodegradation rates of alkanes, derived from first
order kinetics, decreased with increasing oil concentration, but percent residual was ~50% regardless of the
initial concentration. In contrast, the biodegradation rates of PAHs increased with concentration, and the percent
residual increased with oil concentration. Increasing oil concentration resulted in increased abundances of
Rhodobacterales, Altererythrobacter, and Neptuniibacter. However, Alcanivorax abundance was barely detected in
400 and 800 ppm. Overall, oil concentration critically affected the degradation of hydrocarbons and the bacterial
community. |
Mindanao State
University - Iligan Institute of Technology