Use of omic tools to assess methyl tert-butyl ether (MTBE) degradation in groundwater.

This study employed innovative technologies to evaluate multiple lines of evidence for natural attenuation (NA) of methyl tertiary-butyl ether (MTBE) in groundwater at the 22 Area of Marine Corps Base (MCB) Camp Pendleton after decommissioning of a biobarrier system. For comparison, data from the 13 Area Gas Station where active treatment of MTBE is occurring was used to evaluate the effectiveness of omic techniques in assessing biodegradation. Overall, the 22 Area Gas Station appeared to be anoxic. MTBE was detected in large portion of the plume. In comparison, concentrations of MTBE at the 13 Area Gas Station were much higher (42,000 µg/L to 2800 µg/L); however, none of the oxygenates were detected. Metagenomic analysis of the indigenous groundwater microbial community revealed the presence of bacterial strains known to aerobically and anaerobically degrade MTBE at both sites. While proteomic analysis at the 22 Area Gas Station showed the presence of proteins of MTBE degrading microorganisms, the MTBE degradative proteins were only found at the 13 Area Gas Station. Taken together, these results provide evidence for previous NA of MTBE in the groundwater at 22 Area Gas Station and demonstrate the effectiveness of innovative-omic technologies to assist monitored NA assessments.

Enhanced biodegradation of sediment-bound heavily weathered crude oil with ligninolytic enzymes encapsulated in calcium-alginate beads.

The degradation of crude and weathered crude oil following the application of crude and calcium-alginate encapsulated ligninolytic enzymes was studied using in situ microcosms. Changes in the chemical composition of the oil were monitored in crude enzyme extracts, as well as a sediment matrix, for as long as 70 days. Compound-specific effects of ligninolytic enzymes applied to the sediments were observed over time through changes in concentration of total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbons (PAHs) and fractions of saturates, aromatics, resins and asphaltenes (SARA). As the oil weathered, most TPH and PAH fractions showed a rapid decrease in concentration. As sediment oil concentrations decreased following treatment with ligninolytic enzymes, the microbial population was enriched with hydrocarbon-degrading species. This trend demonstrates that the oil fractions initially not bioavailable for microbial degradation, were subsequently released to the sediment via catalytic conversion with laccase and manganese peroxidase, and the oil continues to be biodegraded by microbial populations.

Physiological Peculiarities of Lignin-Modifying Enzyme Production by the White-Rot Basidiomycete Coriolopsis gallica Strain BCC 142.

Sixteen white-rot Basidiomycota isolates were screened for production of lignin-modifying enzymes (LME) in glycerol- and mandarin peel-containing media. In the synthetic medium, Cerrena unicolor strains were the only high laccase (Lac) (3.2-9.4 U/mL) and manganese peroxidase (MnP) (0.56-1.64 U/mL) producers while one isolate Coriolopsis gallica was the only lignin peroxidase (LiP) (0.07 U/mL) producer. Addition of mandarin peels to the synthetic medium promoted Lac production either due to an increase in fungal biomass (Funalia trogii, Trametes hirsuta, and T. versicolor) or enhancement of enzyme production (C. unicolor, Merulius tremellosus, Phlebia radiata, Trametes ochracea). Mandarin peels favored enhanced MnP and LiP secretion by the majority of the tested fungi. The ability of LiP activity production by C. gallica, C. unicolor, F. trogii, T. ochracea, and T. zonatus in the medium containing mandarin-peels was reported for the first time. Several factors, such as supplementation of the nutrient medium with a variety of lignocellulosic materials, nitrogen source or surfactant (Tween 80, Triton X-100) significantly influenced production of LME by a novel strain of C. gallica. Moreover, C. gallica was found to be a promising LME producer with a potential for an easy scale up cultivation in a bioreactor and high enzyme yields (Lac-9.4 U/mL, MnP-0.31 U/mL, LiP-0.45 U/mL).