The Diveristy Of Marine Oil Degrading Bacteria

Currently, marine pollution increased sharply, and the oil pollution is particularly serious, not only threatening the marine environment, organism growth and reproduction, reducing the value of marine, coastaling destruction of facilities, but also affecting the sea hydrometeorological conditions and lowering self-purification ocean ability. The main method of treatment of marine oil pollution is physical, chemical and biological methods. Biological control has lower cost and no secondary pollution, its advantages showed great potential, whereby the oil degrading bacteria become scholars of research.The task started from September 2013, with oil degrading bacteria as the research object, selecting small Shidao (Weihai) water sample preliminary experiment to determine the practical testing program. Several batches made sea water samples from different stations in March 2014 to July 2015 were tested. On the one hand the water samples was used to separate oil degrading bacteria, while bacteria’16S rDNA sequence analysis, and ultimately determine the species category; on the other hand, some of the water samples were for high-throughput sequencing and to do the deep study of diversities. The main work was as follows:Firstly, we selected 13 different oil pollution areas’ water as samples to study, The sites including:Dalian Bay and Pebble Beach (Dalian), Golden Beach and small Shidao (Weihai), Mission Island and Xuejiadao pier (Qingdao), Yantai, Tianjin, Qinhuangdao, Shanghai, public pier (Xiamen), East Point head (Shenzhen). The diese was as the sole carbon source to mediums, sequencings of strains with diesel degradation capability were as followings:6 Bacillus,3 Pseudomonas,2 Sphingobium, 1 Geobacillus,1 Brevibacillus,1 Sulfitobacter,1 Paracoccus,1 Acinetobacter. And also including four new species, which needed to be the further studied. We measured the growth curves and bacterial degradation rate for diesel at 18℃,28 ℃ and 30℃. All strains were growing as "S" curve, inculding adjustment phase, logarithmic phase, stationary phase and decline phase. At 28℃ or 30 ℃, the time of adjustment phase or logarithmic phase would be shorter than 18 ℃. Bacteria diesel degradation rate were all over 30%, different strains has different degradation rate of diesel at different temperatures.Secondly, at the same time we did experiments of the samples from Dalian, Shidao(Weihai), Shenzhen, and added 1%(V/V) diesel to the samples to do high-throughput sequencing, the findings showed that:before and after adding diesel the total OTUs contents were only about 10%, and the total amounts, species of bacteria had reduced significantly. The sample from Dalian, before adding diesel had about 221 generas, while after adding the diesel, it had only 196 generas. And water samples of Shenzhen had changed from 241 generas to 203 generas. Among these, the samples’community structure changed least from Shenzhen, which was affected by the environment. Pseudospirillum were relatively abundant in the three regions, there was different degree of reduction after adding diesel;Colwellia were dominant species for the Shidao(Weihai) and Shenzhen, in Dalian which hadn’t been founded, significantly reduced after added the diesel, and it almost couldn’t adapt to the new environment. Alcanivorax and Alteromonas increased significantly in the three groups of water samples after adding diesel, reflecting the preferences to diesel of the two strains.All in all, the diesel has great impact on the marine environment.