Screening And Identification Of Marine Oil-degrading Microbial Performance

With the rapid development of petroleum industry, oil spill accidents have occurred from time to time. It brings great harm to the marine ecological environment, it is necessary to take timely and effective measures for marine oil spill quickly. Usually adopt physical method, chemical method and biological method to deal with oil spill. The biological method compared with other methods has better economic and environmental benefits, and has broad application prospects. However, due to the inverse environment such as high salt, low temperature and solar radiation in seawater makes the biodegradation restricted, and the effect of bioremediation is not ideal. Therefore, screening of suitable alkane degrading bacterium strains, and make it adapt to adverse environmental conditions of seawater, has great significance to achieve efficient biological degradation.In this paper, screening of microorganism of alkanes degradation from coastal seawater polluted by oil in Dalian Bay, analysis of morphology and16SrDNA identification; test the growth of Alcanivorax sp. A02in different concentration of NaCl and hydrocarbons as sole carbon source. Test the growth and non-growth utilization and degradation of alkanes cells; test the improvement of the growth and the oil degradation of Alcanivorax sp. A02by compatible solute ectoine on high salt conditions; test the bacterial strain which secreted ectoine and5strains of alkane degrading bacteria combined flora on the degradation of alkanes.After the analysis of morphology and16SrDNA identification of the microorganism of alkanes degradation from coastal seawater polluted by oil in Dalian Bay. They respectively belong to the Alcanivorax sp., Pseudomonas sp., Tenacibaculum sp., Dietzia sp. and Acinetobacter sp.. Alcanivorax sp. A02is capable of growth on diesel as the sole carbon source, and degradate diesel in non-growth condition. Alcanivorax sp. A02in0-12%NaCl concentration range, the growth decline by the increase of NaCl concentration.24h, compared to the growth of0%NaCl, the growth of3%NaCl reduced by16.7%. Ectione has significant effect on the growth of Alcanivorax sp. A02in different concentration of NaCl, after adding ectione, the growth of Alcanivorax sp. A02in0-12%NaCl concentration range were greatly improved, the growth amount of3%NaCl is the largest, compared to the growth of0%NaCl, the growth of3%NaCl increased by49.5%. Ectione has significant promoting effect on the alkane degradation of Alcanivorax sp. A02. The average degradation rate of each component of alkane is88.73%. Compared to the single strain Alcanivorax sp. A02, it increased by215.2%. Bacteria DL05which secreted ectoine has significant resistance to assist the effect on Alcanivorax sp. A02. The average degradation rate of each component of alkane is52.8%, Compared to the single strain Alcanivorax sp. A02, it increased by87.6%. The rate of degradation of alkanes of bacteria DL05combined with5strains of alkane degrading bacteria was significantly higher than that of single strain Alcanivorax sp. A02, and the average hydrocarbon degradation rate of each component increased by164.9%.