Varying Conditions for Hexanoic Acid Degradation with BioTiger???

Foreman, Koji¹  Milliken, Charles¹  Brigmon, Robin¹ 

[1] Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

关键词: OIL SAND TAILINGS;    HEXANOIC ACID;    POLYCYCLIC AROMATIC HYDROCARBONS;    CASEIN;    YEASTS;    BIODEGRADATION;    GLUCOSE;    AMINO ACIDS;    OIL SANDS;    AMMONIA;    HEAVY METALS;    WATER;    COMPARATIVE EVALUATIONS;    BACTERIA;    BIOREMEDIATION;    CANADA;    EXTR;   

DOI  :  10.2172/1281780
RP-ID  :  SRNL-STI--2016-00427
PID  :  OSTI ID: 1281780
Others  :  TRN: US1601672

美国|英语

来源: SciTech Connect

【 摘 要 】

BioTiger??? (BT) is a consortium of 12 bacteria designed for petroleum waste biodegradation. BT is currently being studied and could be considered for bioremediation of the Athabasca oil sands refineries in Canada and elsewhere. The run-off ponds from the petroleum extraction processes, called tailings ponds, are a mixture of polycyclic aromatic hydrocarbons, naphthenic acids, hydrocarbons, toxic chemicals like heavy metals, water, and sand. Due to environmental regulations the oil industry would like to separate and degrade the hazardous chemical species from the tailings ponds while recycling the water. It has been shown that BT at 30 C?�� is able to completely degrade 10 mM hexanoic acid (HA) co-metabolically with 0.2% yeast extract (w/v) in 48 hours when starting at 0.4 OD 600nm. After establishing this stable degradation capability, variations were tested to explore the wider parameters of BT activity in temperature, pH, intermediate degradation, co-metabolic dependence, and transfer stability. Due to the vast differences in temperature at various points in the refineries, a wide range of temperatures were assessed. The results indicate that BT retains the ability to degrade HA, a model surrogate for tailings pond contaminants, at temperatures ranging from 15?��C to 35?��C. Hexanamide (HAM) was shown to be an intermediate generated during the degradation of HA in an earlier work and HAM is completely degraded after 48 hours, indicating that HAM is not the final product of HA degradation. Various replacements for yeast extract were attempted. Glucose, a carbon source; casein amino acids, a protein source; additional ammonia, mimicking known media; and additional phosphate with Wolffe???s vitamins and minerals all showed no significant degradation of HA compared to control. Decreasing the yeast extract concentration (0.05%) demonstrated limited but significant degradation. Finally, serial inoculations of BT were performed to determine the stability of degradation over several generations. Overall, BT has shown to be moderately flexible for HA co-metabolic biodegradation.