The use of bacteria is a good method for
biodegradation of polycyclic aromatic hydrocarbons due to
their fast-growing and cost effectiveness. Bacteria can
completely mineralize such toxic compounds to harmless
by-products. ASU-035 is a bacterial strain, which was
isolated from oil contaminated soil. It was identified as
Achromobacter denitrificans on the basis of the nucleotide
sequence of 16S rRNA gene, and deposited in GenBank
under accession number KC342253. Achromobacter denitrificans
have been tested for utilization of pyrene as a sole
source of carbon and energy. Some pyrene degradative
enzymes and ability of this strain for biosurfactants production
have been studied. The results illustrated that the
strain could utilize 76.5 mg/L of pyrene (100 mg/L) within
18 days with growth rate and mean generation time
0.033 h-1 and 30.3 h, respectively. The maximum specific
activities (U/mg protein) of pyrene dioxygenase, catechol
1,2 dioxygenase (C12O), and catechol 2,3 dioxygenase
(C23O) were 0.78 ± 0.12, 0.41 ± 0.05, and 0.2 ± 0.01,
respectively. Achromobacter denitrificans could enhance
the bioavailability of pyrene to get use of it as a sole carbon
source by increasing the emulsification activity to
11.5 ± 2.1 U/mg proteins and cell-surface hydrophobicity
to 39 ± 1.3 %.