Artículo de revista
Molecular characterization and evaluation of oil-degrading native bacteria isolated from automotive service station oil contaminated soils
Fecha
2016-04Registro en:
Zafra G., Regino R., Agualimpia B., Aguilar F., 2016, Molecular characterization and evaluation of oil-degrading
native bacteria isolated from automotive service station oil-contaminated soils, Chemical Engineering Transactions, 49, 511-516
DOI: 10.3303/CET1649086
10.3303/CET1649086
978-88-95608-40-2
2283-9216
Autor
Zafra, German
Agualimpia Valderrama, Bayron-Enrique
Regino, Ronald
Aguilar, Fabiola
Institución
Resumen
In this study, a hydrocarbon-degrading mixed inoculum which is able to use used oil as sole carbon source,
was selected from 15 bacterial isolates obtained from automotive service station oil-contaminated soils.
Degrading microorganisms were isolated using different oils as sole carbon source and identified by the
amplification and sequencing of the 16s rRNA sequences. In addition, the presence of hydrocarbon-degrading
genes such as catechol 2,3 dioxygenase (nahH), alkane monooxygenase (alkB), Gram-negative (GN-RHDα)
and Gram-positive PAH-Ring Hydroxylating Dioxygenase alpha (GP-RHDα) was analyzed by PCR and the
molecular diversity by LSSP-PCR methods. Four (4) out of fifteen (15) isolates corresponding to
Stenotrophomonas maltophilia, Pseudomonas aeruginosa and Klebsiella pneumoniae showed significant
differences regarding oil/grease removal in liquid culture after 72 hours. Subsequently, a degrading mixed
inoculum composed of these isolates was constructed and its degrading potential tested in a two-liter
bioreactor containing unsterile liquid oily wastes with 0.8 % (w/v) Total Petroleum Hydrocarbons (TPHs)
concentration for 42 days. The use of the mixed inoculum led to a decrease of 98.4 % Biological Oxygen
Demand (BOD), 97.5 % Chemical Oxygen Demand (COD) and 97.2 % TPHs after 40 days. Further scale-up
of the process to five liters using 0.2 % (w/v) unsterile oily wastes produced similar results, with a reduction of
85 % BOD, 39 % COD and 87 % TPHs after 38 days. The degrading mixed microbial inoculum presented high
potential for the treatment of impacted soils at automotive service stations and sites polluted with oily wastes
due to its elevated growth at high hydrocarbon concentrations and its capacity to utilize oils as energy source.