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Effect of a mixed culture on co‐oxidation during the degradation of saturated hydrocarbon mixture
Author(s) -
Ko S. H.,
Lebeault J. M.
Publication year - 1999
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1046/j.1365-2672.1999.00797.x
Subject(s) - biodegradation , strain (injury) , hydrocarbon , pristane , decalin , hexadecane , alkane , chemistry , population , degradation (telecommunications) , cometabolism , pseudomonas , organic chemistry , bacteria , bioremediation , microbiology and biotechnology , biology , catalysis , telecommunications , genetics , demography , anatomy , sociology , computer science
Two bacterial strains, Pseudomonas aeruginosa K1 and Rhodococcus equi P 1, were used to degrade cyclo‐alkanes (such as decalin) by a co‐oxidation mechanism. Both strains possessed the capacity to degrade a broad range of n ‐alkane mixtures (C7 to C28) within 24 h of incubation. Strain P1 rapidly degraded 10 g l −1 pristane within 24 h of incubation (μ = 0·36 h −1 and Y x/s = 0·6). The addition of hexadecane as a growth substrate (above 0·5%, v/v) resulted in complete degradation of 1% (v/v) decalin by strain P1 via a co‐oxidation mechanism. Co‐oxidation to degrade decalin or pristane by strain K1 proved unsuccessful. Strain P1 was able to degrade decalin totally in a saturated hydrocarbon mixture. Strain K1 was only able to degrade hexadecane from the hydrocarbon mixture, but its degradation rate was higher than that of strain P1. Therefore, there was competition for the hexadecane needed to co‐oxidize decalin. As a result, degradation of the hydrocarbon mixture, especially decalin, was incomplete in a mixed culture of strain P1 and K1. Serial addition of hexadecane (twice) allowed complete degradation of the remaining decalin by strain P1. Also, the biodegradation rate of the hydrocarbon mixture by a microbial population from gasoline‐contaminated soil was delayed by addition of strain K1 to the population, while the addition of strain P1 resulted in an increase in the biodegradation rate.