Assessing crude oil bioremediation using catabolic and metabolic microbial biosensors

摘要

Microbes can be used as whole-cell biosensors when transformed with a suitable reporter mechanism, such as bioluminescence. They can be used to measure either the toxicity of a system (metabolic sensors) or the presence of hydrocarbons (catabolic sensors). Six different bioluminescent biosensors - three metabolic and three catabolic - were used to assess the progress of bioremediation in a series of soil microcosms. The microcosms were spiked with five different oils: diesel oil; and four different crude oils spanning a range of physical properties from light to very heavy. The microcosms were nutrient-amended and incubated for 120 days, and the biosensors tested against extracts of the incubated soils. The catabolic biosensors responded positively and sensitively to hydrocarbons in all of the different oils; one was still recording a large positive response at the end of the incubation period. The responses were greatest for the light and medium crude oils. The metabolic biosensors were sensitive to all of the oils; there was a slight initial decrease in toxicity, followed by a sharp increase in toxicity after 30 days incubation, which was not ameliorated over the course of the experiment. The dualistic approach, utilizing both types of biosensor, offers advantages over traditional biosensor technology.