The diesel-degrading capabilities of Acinetobacter calcoaceticus isolates LT1, LT1A and V2 were established in previous studies. LT1 and LT1A were isolated from diesel-contaminated soil and V2 was from soil contaminated with used engine oil. Isolates were grown in Bushnell-Haas medium supplemented with 1% sterile diesel. Determination of diesel-degradation patterns by gravimetric analysis and harvesting of cells for RNA extraction were performed at regular time intervals over a 60 day period. The involvement of genes alkM, alkR, rubA, rubB, estB, lipA, lipB, and xcpR in hydrocarbon degradation has been reported in previous studies. LT1, LT1A, and V2 were compared in terms of gene expression levels by real-time quantitative PCR. Expression levels were assessed by relative quantification and normalized against the 16S rRNA reference gene using the Relative Expression Software Tool - XL (REST-XL). Amplification of all genes, except rubB, was achieved with a high degree of efficiency. The expression of rubA, alkM, alkR, xcpR, and lipB based on pair-wise randomization, was all down-regulated in LT1A in relation to LT1. Highest expression levels of the aforementioned genes were documented during the initial stages of incubation for LT1 while LT1A showed highest expression levels midway through the study period. LT1, LT1A, and V2 achieved 58.6%, 51.7%, and 48.3% diesel degradation after 5 days of incubation, respectively. The higher percentage of diesel degradation achieved by LT1 can be attributed to higher levels of overall gene expression in the initial stages of degradation. Amplification of alkane hydroxylase alkM of V2 revealed a possible second hydroxylase gene that was expressed after 20 days of incubation. Amplification of alkR and xcpR in V2 isolates also resulted in multiple product formation. Very low lipB and lipA expression was detected in LT1 and LT1A and the absence of lipA expression in V2 suggests that lipases were not involved in diesel degradation. In contrast, estB was predominantly expressed in V2, and suspected to be involved in the release of a bioemulsifier that was only observed in V2 samples. Although all three isolates were comparably efficient in degrading diesel, the results of this study suggest that different mechanisms may be employed in the degradation process. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2009.

Bacteria of the genus Acinetobacter are known to be involved in the degradation, leaching and removal of various hazardous compounds from the environment. Several studies of Acinetobacter spp. have reported on the genes involved in alkane degradation; but less is known about the proteins that are expressed at certain points within the degradation period. Acinetobacter sp. LT1A and Acinetobacter sp. V2 were isolated from diesel- and used engine oil-contaminated soils respectively. In a previous investigation (Toolsi, 2008), these isolates have been shown to demonstrate different gene expression patterns during diesel degradation using real time PCR. The real time PCR data showed that isolate V2 made use of multiple alkane hydroxylases whereas LT1A made use of only one, and the expression of the alkane hydroxylase regulator alkR and secretory protein xcpR also revealed multiple product formations in isolate V2 as compared to LT1A. Thus the objectives for the current investigation were to monitor the hydrocarbon degradation ability of Acinetobacter sp. isolates V2 and LT1A using medium chain (C14) and long chain (C28) hydrocarbon substrates and to compare the hydrocarbon degradation abilities and protein expression patterns of both isolates. To achieve this, the isolates were grown for 20 days in Bushnell Haas liquid medium supplemented with tetradecane (C14) or octocosane (C28) as a sole carbon source. Gravimetric analysis was used to monitor degradation and whole cell protein was extracted from the culture medium throughout the 20-day study period. The protein expression patterns were visualized using 1D and 2D PAGE. The 2D PAGE images were analyzed using the PDQuest Advanced 2D image analysis software (BIORAD). By day 20, approximately 90% of C14 was degraded by both isolates, whereas only 36% of C28 had been broken down. In both the C14 and C28 degradation assays, the isolates achieved significant amounts of hydrocarbon degradation as compared to the abiotic controls. One-dimensional and 2D SDS-PAGE gels indicated that there are observable differences in protein expression patterns between the isolates during C14 and C28 degradation. Both isolates achieved similar rates of hydrocarbon usage, but appear to do so using different, unidentified, protein systems. Analysis of the 2D-SDS PAGE gel images revealed that more proteins were required for the utilization of the long chain alkane (C28) as compared to the medium chain alkane (C14) for both isolates. Potential spots of interest were identified from the 2D SDS-PAGE images and sequenced. The identities of these proteins were found to be: a conserved hypothetical protein, TonB-dependent receptor protein, Peptidyl-prolyl-cis-trans isomerase and a Protein containing DUF1559. No alkane hydroxylase components were detected in this study. This investigation demonstrated the need for more studies at the proteomic level. Future investigations should focus on the insoluble subproteome of the isolates and make use of larger sample sizes (replicates) to reduce variation in spot detection and quantification. Genomic sequencing of the isolates will also shed light on the genetics and biochemistry of alkane metabolism in these Acinetobacter sp. isolates. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2012.

New Zealand's Antarctic research station, Scott Base, is currently 100% reliant on aviation turbine fuel and existing diesel generator sets to produce the heat and electricity necessary to sustain staff activities. Decreasing fuel consumption at Scott Base has benefits economically, politically and environmentally. A method of reducing fuel consumption and increasing base independence that is receiving considerable attention from Antarctica New Zealand is the addition of wind power to the existing energy system. A performance-objective design of a wind-diesel hybrid energy system for Scott Base is proposed in order to determine the most effective hybrid system configuration with the lowest cost within a set of system constraints. A demand side management technique is also evaluated as a measure to further increase potential fuel savings. Modelling is completed using the simulation tool HOMER and results are presented for several different system configurations.

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Thesis (M.S.)--University of Nevada, Reno, 2007. / "May, 2007." Includes bibliographical references. Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2007]. 1 microfilm reel ; 35 mm.

Thesis (Ph. D.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains xi, 151 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 100-106).