Protocol for laboratory testing of crude-oil bioremediation products in freshwater conditions

Abstract

In 1993, the Environmental Protection Agency, National Risk Management Research Laboratory (EPA, NRMRL), with the National Environmental Technology Application Center (NETAC), developed a protocol for evaluation of bioremediation products in marine environments [18]. The marine protocol was adapted for application in freshwater environments by using a chemically defined medium and an oil-degrading consortium as a positive control. Four products were tested using the modified protocol: two with nutrients and an oleophilic component; one with nutrients, sorbent, and organisms; and one microbial stimulant. A separate experiment evaluated the use of HEPES and MOPSO buffers as replacements for phosphate buffer. The oleophilic nutrient products yielded oil degradation similar to the positive control, with an average alkane removal of 97.1+/-2.3% and an aromatic hydrocarbon removal of 64.8+/-1.2%. The positive control, which received inoculum plus nutrients, demonstrated alkane degradation of 98.9+/-0.1% and aromatic degradation of 52.9+/-0.1%. The sorbent-based product with inoculum failed to demonstrate oil degradation, while the microbial stimulant showed less oil degradation than the positive control. Replacement of phosphate buffer with other buffers had no significant effect on one product's performance. Differences in product performance were easily distinguishable using the protocol, and performance targets for alkane and aromatic hydrocarbon degradation are suggested.

Biodegradation of crude petroleum oil and environmental pollutants by Candida tropicalis strain

“…The limited glucose concentration is essential to avoid catabolite repression. Aeration plays an important role in oil bioremediation and is considered a rate limiting factor in the biodegradation of marine oil spills where, oxygen is necessary for initial breakdown of hydrocarbon and subsequent reactions (Haines et al, 2003). The presence of phosphate plays a critical role and its inadequate supply may result in slowing the rate of biodegradation (Haines et al, 2003).…”

Laboratory evaluation of oil spill bioremediation products in salt and freshwater systems

“…In previous work conducted by our laboratory, Haines et al [10] proposed a freshwater protocol for testing bioremediation products to include performance targets, a positive control, and a defined nutrient formula. Four products were tested and two were able to degrade >90% alkane and >60% aromatic hydrocarbons within 28 days.…”

“…In this work, the MPN procedure was used as described [20] for saltwater and modified for fresh water by using SFW medium rather than GP2 [10]. For both alkane-and PAH-degrader enumeration, the MPN was calculated using a computerized enumeration program [11].…”

Biodegration of Tapis Crude Oil Using Consortium of Bacteria and Fungi: Optimization of Crude Oil Concentration and Duration of Incubation by Response Surface Methodology

“…Alkanes of intermediates chain length (C 10 -C 24 ) are often degraded immediately, while long chain alkanes are resistant to microbial degradation (Ijaha & Antaib 2003). According to Haines et al (2003) the decline in bacterial growth upon increased oil concentration was due to oxygen scarcity. The result also showed that extension of incubation period (336 h) did not increase in TPH degradation.…”