Abstract:
Human activities have both direct and indirect effects on Antarctic ecosystem; it is the main reason for petroleum hydrocarbon contamination because diesel oil is used as the main power source in the area. This work aimed to study the role of indigenous bacteria from Antarctic soil involved in diesel oil biodegradation under low temperature. The samples were collected from the mountain back from the Great Wall research station, Antarctica. The soil microcosms were constructed using 1% and 3% (w/w) diesel oil as substrate under 15°C. When compare abiotic control with natural attenuation and biostimulation (adjust C: N: P to 100:10:1), the result showed that indigenous bacteria were able to degrade diesel oil. Nevertheless, the addition of nutrient enhanced diesel oil biodegradation efficiency at the early stage. The Isolation of pure cultures from soil microcosm found that Pseudomonas spp., grouped in Gammaproteobacteria and Sphingomonas sp., grouped in Alphaproteobacteria degraded diesel oil and had biosurfactant production potential. The results of microbiome analysis using the analysis of 16S rRNA gene amplicon and shotgun metagenomics showed that Gammaproteobacteria, Alphaproteobacteria, and Actinobacteria are predominant in the soil microcosms with diesel oil. In addition, the genes involved in diesel oil biodegradation found in the soil microcosms were belong to Gammaproteobacteria, Alphaproteobacteria, and Actinobacteria. Therefore, these bacteria may play an important role in diesel oil degradation in the soil microcosms under low temperature. This is the first report that studies the role of bacteria involved in diesel oil biodegradation under low temperature; the effects of nutrient and diesel oil concentration on bacterial community structure were investigated. The information obtained from this study can be used for the better understanding of the role of bacterial community and further develop a suitable method for remediation of contaminated site under low temperature.