The supernatant harvested from a mesophilic,
molasses-fed, non-methanogenic bioreactor, which is rich
in nitrogen, phosphorous, metals, free amino acids,
Sporolactobacillus
sp.,
Prevotella
sp., and
Clostridium
sp.,
is diluted with tap water and tested as the bioagent to
catalyze diesel degradation in soil. Outdoor experiments
are performed under the following conditions to assess the
effectiveness of the bioagent: diesel doses: 9–15 mg TPH/g
soil; bioagent concentrations and dose: 1–5% at
60 ml/day; soil sample size: 600 g; ambient temperatures:
28–32 °C, and relative humidity: 40–82 % (TPH: total
petroleum hydrocarbons). Diesel degradation in soil treated
with 3 % bioagent, which proceeds at the rates of
1.04–1.55 mg TPH/g soil-day, is completed in about a
week with up to 83 % efficiencies. In contrast, diesel
degradation in soil sprinkled with water (60 ml/day) proceeds
at the rate of 0.3 mg TPH/g soil-day that achieves
15–22 % degradation efficiencies. The addition of 3 %
bioagent yields desired soil moisture content (10–15 %),
soil pH (6.8–8.2), and nutrition inputs. Both
Sporolactobacillus
sp. and
Prevotella sp. grown on molasses are
robust, tolerant high diesel doses, able to utilize
hydrophobic hydrocarbons, and readily adaptable to the
soil environment. Most notably, prior acclimatization is not
required to enable these properties.