Presence of opportunistic oil-degrading microorganisms operating at the initial steps of oil extraction and handling.

Hydrocarbon-degrading microorganisms from natural environments have been isolated and identified using culture-dependent or molecular techniques. However, there has been little research into the occurrence of microorganisms incorporated into crude oil in the initial steps of extraction and handling, which can reduce the quality of stored petroleum. In the present study, a packed-column reactor filled with autoclaved perlite soaked with crude oil was subjected to a continuous flow of sterile medium in order to determine the presence of potential hydrocarbon degraders. Microorganisms developed on the surface of the perlite within a period of 73 days. DNA was extracted from the biofilm and then PCR-amplified using 16S rRNA bacterial and archaeal primers and 18S rRNA eukaryotic primers. No amplification was obtained using archaeal primers. However, denaturing gradient gel electrophoresis (DGGE) revealed the presence of unique bands indicating bacterial and eukaryotic amplification. Excision of these bands, sequencing, and subsequent BLAST search showed that they corresponded to Bacillus sp. and Aspergillus versicolor. The fungus was later isolated from intact perlite in agar plates. A bacterial clone library was used to confirm the presence in the biofilm of a unique hydrocarbon-degrading bacterium closely related to Bacillus sp. Analysis of the petroleum components by gas chromatography showed that there n-alkanes, aromatic hydrocarbons, and carbazoles were degraded.

Increasing the donor pool using en bloc pediatric kidneys for transplant.

OBJECTIVES: En bloc pediatric kidney transplants (EBPKT) are still a subject of controversy. The aim of this study was to determine whether acceptable long-term graft survival and function can be achieved in EBPKT compared with the transplant of single, cadaveric, adult donor kidneys. METHODS: A retrospective review was conducted of 66 recipients of en bloc kidneys from cadaveric pediatric donors and 434 patients who underwent transplantation with a single kidney from an adult donor between January 1990 and May 2002 at the authors' hospital. The recipients were well-matched demographically. Both transplant groups were analyzed for short- and long-term performance in terms of transplant outcome and quality of graft function. RESULTS: Overall death-censored actuarial graft survival rates at 1 and 5 years were 89.2% and 84.6% in the adult kidney transplants (AKT) and 83.3% and 81.1% in EBPKT, respectively (P=0.56). In the EBPKT group, graft function was improved over that observed in AKT. Vascular thrombosis was the most common cause of graft loss in EBPKT. Acute rejection occurred more frequently in AKT and Cox's regression analysis indicated that undergoing an AKT was a predictive factor for acute vascular rejection (adjusted risk ratio, 3.8; 95% confidence interval, 1.4-10.2; P=0.001). CONCLUSIONS: Overall graft survival was similar in both groups, vascular complications were the main cause of graft loss in EBPKT, and the EBPKT showed excellent long-term graft function and a low incidence of acute rejection.