Browsing by Subject "biologinen öljynhajotus alhaisessa lämpötilassa"

As a result of oil transport and pumping from the ground there is a constant risk for oil spills. The impact of an oil spill to the marine ecosystem can be significant. Therefore there has been growing interest to create new biological ways to degrade oils hydrocarbons by using microbes and plants ability to degrade oil to less harmful compounds. Because the biodegradation of oil in the nature is slow microbe enrichments and nutrient fertilizers can be developed to stimulate it. Compared to the oceans the Baltic Sea has significantly lower salinity and also temperature is lower than the average ocean temperature. Therefore it is important to take into consideration the unique features of the Baltic Sea when new enrichments are developed for oil spill response. The aim of this study was to enrich samples from the Baltic Sea coastal areas that had previously contaminated with oil. These samples were enriched with crude oil and with marine diesel oil. The oil-degradation efficiency of the enrichments were evaluated using several methods and the changes in microbial diversity was also examined among the process. The aim was to enrich microbial population which can be used in combination with carrier materials as an ecological and inexpensive oil spill recovery method in the Baltic Sea area. The biodegradation of the oil during enrichments were detected by carbon dioxide measurements, biodegradability and hydrocarbon analysis. Changes in the cell concentration during the enrichments were measured by Live/Dead- and DAPI staining. Changes in the microbe activity was detected with ATP-measurements. The oil degradation effectiveness of the enrichments were examined with HALO-plating and with emulsification test. Changes in the microbial diversity during the enrichment was examined with Ion Torrent sequencing. The results showed that used methods were suitable for estimating oil biodegradation, microbial activity, cell concentration and microbial diversity changes in the samples. The enrichment temperature was the most significant factor influencing the oil degradation efficiency and microbial diversity of the enrichments. The influence of the sampling site was not so significant. Crude oil biodegraded more efficiently by crude oil enri0chments than the marine diesel oil by marine diesel oil enrichments. According to the chemical and microbiological methods used in this study oil biodegradation was observed at low temperatures (5 and 15 °C). Several oil-degrading enrichments working at lower temperatures were obtained in this study. However, the biodegradation of oil was relatively slow and would be important to examine if the bigger amounts of nutrients, as well as the use of carrier materials would enhance the biodegradation process at cold temperature. The OILRES-project (Multilevel assessment of sustainable oil spill response measures and their impact on Arctic and subarctic marine environments) where the master´s thesis were done was funded by the Academy of Finland and it is co-operation of Finnish Environment Institute (SYKE) and Technical Research Centre of Finland (VTT Ltd).