Activation of an indigenous microbial consortium for bioaugmentation of pentachlorophenol/creosote contaminated soils

• Published in: Applied microbiology and biotechnology 1994-01, Vol.40 (6), p.926-932
• Main Authors: Otte, M.P, Gagnon, J, Comeau, Y, Matte, N, Greer, C.W, Samson, R
• Format: Article
• Language: English
• Subjects: biodegradation; Biodegradation of pollutants; Biological and medical sciences; bioreactors; Biotechnology; creosote; Environment and pollution; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; pentachlorophenol; soil microorganisms; soil pollution
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/BF00174001

Soil activation, a concept based on the cultivation of biomass from a fraction of a contaminated soil for subsequent use as an inoculum for bioaugmentation of the same soil, was studied as a method for the aerobic biodegradation of pentachlorophenol (PCP) and polycyclic aromatic hydrocarbons (PAH) in contaminated soils. A microbial consortium able to degrade PCP and PAH in contaminated soil from wood-preserving facilities was isolated and characterized for PCP degradation and resistance. To obtain an active consortium from the contaminated soil in a fed-batch bioreactor,the presence of soil as a support or source of nutrients was found to be essential. During the 35 days of bioreactor operation, residual PCP in solution remained near zero up to a loading rate of 700 mg/l per day. The PCP mineralization rate increased from 70 mg/l per day when no PCP was added to the bioreactor to 700 mg/l per day at the maximum loading rate. The consortium tolerated a PCP concentration of 400 mg/l in batch experiments. Production of a PCP-degrading consortium in a fed-batch slurry bioreactor enhanced the activity of PCP biodegradation by a factor of ten. PAH biodegradation increased, during the same time period, by a factor of 30 and 81 for phenanthrene and pyrene, respectively. Preliminary laboratory-scale results indicated that a significant reduction in the time required for degradation of PCP and PAH in contaminated soil could be achieved using activated soil as an inoculum.