Bioaugmentation efficiency investigation on soil organic matters and microbial community shift of diesel-contaminated soils

• The degradation rates of total petroleum hydrocarbon were negatively associated with the level of soil organic matter.
• The Intergenic spacer array can help predict the successfulness of a bioaugmentation approach for TPH soil remediation.
• The MDS statistical result indicated an apparent path of bacterial community shift followed by the TPH degradation stages.

This study investigated effects of microbial community shift, soil organic matter (SOM), and diesel contamination approaches with three independent batches. The SOM levels ranged from 2% to 55%. Diesel oil was artificially contaminated to soils with different approaches to achieve the highest level of 10000 TPH mg/kg. The three batches provided the same results regarding the negative influence of SOM on the TPH degradation rate (k). The results of Nonmetric multidimensional scaling indicated that (1) the bacterial community shift significantly associated with the TPH degradation stages; (2) when SOM levels were close to each other, their degradation performance and bacterial communities were similar to each other, and (3) dynamics of bacterial communities could influence the TPH degradability. In addition, the Intergenic spacer (ITS) microarray results emphasized the advantages of determining an effective bioaugmentation, confirming the successfulness of the inoculation, and identifying the survivors. Microbial community shift and SOM levels indeed influenced the TPH degradation.