2.5 Microbial and plant growth assay
This study determined the degradation efficiency of petroleum
hydrocarbons by three bacterial strains isolated from long-term
petroleum-contaminated soil. In addition, the effects of three bacteria
strains and their synthetic communities on the growth of maize seedlings
under petroleum hydrocarbon stress were investigated. Briefly, the crude
oil was evenly mixed with sterilized oilfield control soil at a
proportion of 0.5% and stored for four weeks. Maize seeds were
surface-sterilized with 70% ethanol and 50% bleach before germination
in the hydroponics platform. All SynCom strains were grown to saturation
in quarter-strength tryptic soy broth and washed using
phosphate-buffered saline before root inoculation.