Functional microbiome and phytoremediation enhance soil diesel degradation via enzyme activity

Abstract

This study investigates the enhancement of diesel degradation in contaminated soil through the synergistic effects of functional microbiomes and phytoremediation, emphasizing increased enzyme activity. The approach integrates a hydrogen-producing microbiome (HMb) with phytoremediation techniques. Observations revealed changes in soil conditions, including increases in moisture levels from 12.5% to 20% and a shift in pH from 6.9 to an alkaline range of 8.0-8.5 due to the treatment. Organic matter content also improved, supporting microbial activity. These modifications were closely monitored to evaluate their impact on microbial growth and enzyme activity. The findings showed that total petroleum hydrocarbons (TPH) in diesel-contaminated soil decreased by 78.1% using the combined HMb and phytoremediation method. This decrease was markedly higher than the 30.4% achieved through water drenching and the 30.9% with HMb alone. Central to this success were Clostridium sp. and Sporolactobacillus sp., which played essential roles in hydrocarbon degradation. Improved soil conditions supported an increase in microbial populations, with bacterial counts peaking at 6.0 x 10¹¹ by day 4, enhancing degradation. Additionally, Bermuda grass survival rates increased to 35% by day 35. In the HMb and planting combination, amylase activity peaked at 100% by day 10, significantly aiding degradation, although it later decreased to 1% by day 35. This research presents a robust strategy for diesel-contaminated soil remediation, highlighting significant advancements in microbial growth and degradation efficiency.

Keywords: Clostridium sp.; Diesel emulsification; Hydrogen-producing microbiome; Soil enhancement; Sporolactobacillus sp.; Synergistic biodegradation.