Development and utilization of oil and gas resources in cold area and unsound system of environmental protection result in a devastating effect on ecosystems and enviroments in alpine regions. Utilizing microbial degradation to alleviate the pollution of oil has so far become the most important environmental remediation technology, which can be no secondary pollution by situ remediation in the pollution region and is also regarded as a safe, environmental friendly and low-cost technology. However, The lack of low temperature crude oil degrading strain resources limit the microbial remediation technology used in a cold environment, looking for low-temperature oil degradation bacteria play an important role in the improvement of bioremediation technology and application of cold environment remediation.Being the highest plateau, Tibet Plateau has long been known as the roof of the world. The long-term low temperature conditions make the soil of the Qinghai Tibet Plateau having a large number of psychrophilic microorganisms and cold tolerance of microbial resources. We launched a study to preliminarily investigate the distribution characteristics of lowtemperature crude degrading bacteria in the soil of Tibet Plateau, in addition, the degrading activity of target germs has been researched, which laid the basis of both properly utilizing microbial resources and potential application in cold environment. Our main conclusions were as follows:(1) 44 culturable bacterial strains have been isolated from the two crude pollution areas from Qaidam basin(Cold Lake and HuaTuGou), these stains can be divided into 3 phylum and nine genera. In detail, we got 7 Actinobacteria, 11 Firmicutes and 15 Proteobacteria, among which Proteobacteria cultivable bacterial was γ-mycetozoan and Pseudomonas stutzeri which had highest frequency. Analyzing the target strain from two polluted crude areas of Qaidam basin, we found lots of various bacilluses in Cold Lake, which was contrary to Huatugou where Actinomyces was absolutely dominant germ, and the other three strains maybe were potential new spicies.(2) 102 crude oil degrading bacterial strains have been isolated from the soil of Qilian Mountain and GRM, and among them, the 13 strains were from junior Babao River, the 40 strains were from Yeniugou, the 32 strains were from Binggou, the 5 strains were from Baopinghe and the 12 strains were from GRM. We got 40 Actinobacteria, 12 Firmicutes, 12 Bacterioidetes, 38 Proteobacteria, among which the γ-Proteobacteria, with accounted for about 33%, was dominant in quantity, the amount of α-Proteobacteria and the amount of β-Proteobacteria only a few. Investigating the distribution characteristics of crude oil degrading bacterial from soil of Qilian Mountain and GRM, we drew a conclusion that Pseudomonas and Arthrobacter were absolutely dominant germs.(3) Some of isolated germs have been cultivated in order to test their degradation activity by observing their growth situation, the result showed that only some of them had degradation activity and the strain from crude oil polluted soil with excellent degradation activity was Nocardia. However, Most of strains with excellent degradation activity were Acinetobacter in crude oil uncontaminated soil. The interesting is, most of the strains with excellent degradation activity were distributed in crude oil uncontaminated soil, but the reason required to further research.(4) In the study of degradation characteristics, strains YF28-1(8)( Rhodococcus erythropolis)and YF24-3(2)(Pseudomonas mandelii)with excellent degradation activity have been took as example, wanted to know that the two strains were able to biodegrade alkane and aromatic hydrocarbons constituents in different degree and especially effective to linear saturated alkane by means of GC-MS test. The result showed that the degradation rate were between 60-90%. Comparison of the degradation effect of these two strains was found, YF24-3(2) was more capable to degrade saturated alkane than YF28-1(8), YF28-1(8) was more capable to degrade arene and PAH than YF24-3(2).(5) Investigating the two strains’ contributing factors of crude biodegradation, we gained their optimal conditions. The optimal conditions of YF28-1(8) included: pH at 7.5, temperature at 30℃ and inoculum size of 800μL;and the optimal conditions of YF24-3(2) included: pH at 7.5, temperature at 20℃ and inoculum size of 600μL, both of their quantity and degradation rate could reach maximum in only 8 days, meanwhile, low concentration surfactant named Tween 80 could not improve their degradation rate. |