Uptake and utilization of n-octacosane and n-nonacosane by Arthrobacter nicotianae KCC B35

Arthrobacter nicotianae KCC B35 isolated from blue-green mats densely covering oil sediments along the Arabian Gulf coast grew well on C10 to C40 n-alkanes as sole sources of carbon and energy. Growth on C20 to C40 alkanes was even better than on C10 to C18 alkanes. Biomass samples incubated for 6 h with n-octacosane (C28) or n-nonacosane (C29) accumulated these compounds as the predominant constituent alkanes of the cell hydrocarbon fractions. The even chain hexadecane C16 and the odd chain pentadecane C15 were the second dominant constituent alkanes in C28 and C29 incubated cells, respectively. n-Hexadecane-incubated cells accumulated in their lipids higher proportions of C16-fatty acids than control cells not incubated with hydrocarbons. On the other hand, C28 and C29-incubated cells did not contain any fatty acids with the equivalent chain lengths, but the fatty acid patterns of the cell lipids suggest that there should have been mid-chain oxidation of these very long chain alkanes. This activity qualifies A. nicotianae KCC B35 to be used in cocktails for bioremediating environments polluted with heavy oil sediments.