Changes of FAME profiles as a marker of phenol degradation in different soils inoculated with Pseudomonas sp. CF600

Fatty acid profiles of three different sterile soils contaminated with phenol at the concentrations of 1.7, 3.3 and 5.0 mg g−1 and inoculated with phenol-degrading Pseudomonas sp. CF600 were investigated. The rate of phenol biodegradation and survival of inoculants in contaminated soils were also studied. It was found that introduced strain was able to completely degrade phenol added at the highest dose during 108 days in MF and WM soils, and 124 days in PF soil, whereas at the smallest dose within 60 days independently of soil type. In all phenol-polluted soils the decrease of the initial inoculum was estimated and at the end of the experiment in soils treated with phenol at the concentration of 5.0 mg g−1 constituted 18, 21 and 25% of initial number in MF, PF and WM soils, respectively. Under phenol exposure important changes in profiles of FAMEs obtained directly from soils were detected. The most significant alterations were observed in soils contaminated with the highest phenol dosage and related to 17:0 cy and 19:0 cy ω8c cyclopropane fatty acids. Over time with decreasing phenol concentration the decline of 17:0 cy amount was observed. In turn, in all polluted soils 19:0 cy ω8c appeared first time on day 12 when the initial phenol doses declined about 60% in WM and MF and about 40% in PF soil. Other changes in FAME composition included the slight increase of straight-chain, the decrease of branched, hydroxylated and unsaturated fatty acids. The value of sat/unsat ratio, the occurrence and distribution of specific cyclopropane fatty acids in FAME profiles might be useful for the estimation of phenol biodegradation progress.