Distribution Of Syntrophism Basteria And Phylogenic Study In The Process Of Anaerobic Crude Oil Degradation

In this study, to simulate the biological syntrophism degradation of butyric acid and acetic acid in laboratory condition, anaerobic enrichment from Shengli L801 high-temperature oil reservoir were used as inculation, butyric acid and acetic acid as mesostate from crude oil degradation in fossil oil were used as unique carbon, samples were enriched with or without methagen in constant temperature bin at 60℃. State and variation of enrichment in different condition and generation were determined by means of microscope, degradation of acid and methane production via gas chromatography, PCR-DGGE. Simultaneously, in this experiment, two anaerobic strains isolated from oil contaminant soil and oil reservoir water were studied by morphology, physiology biochemical identification and phylogenetic study.In conclusion: 1) The physiological, ecological and PCR-DGGE experimental results showed community of syntrophism degrading acetic acid or butyric acid had been enriched successfully, which can promote the research of mechanism of degrading refractory compounds; 2) Community of syntrophism polymer had significantly variation in different condition and generation, bacteria abled to syntrophism metabolise exist in syntrophism polymer; 3) Methanogen and anerobic bacteria were observed in syntrophism polymer by microscope. After cultivation for fourth generation, there were at least two strains in each syntrophism polymer. It may be due to the strcture of syntrophic communities. Syntrophic metabolism of commuitities were slowly and this study proved this view; 4) Degradation rate of acetic acid was greater than butyric acid at 60℃. After cultivation for several generations, syntrophism acetic acid enrichment with exogenous methanogen was shorted the start time, and improved their capability to product methane, however, oppositely others; 5) xyl-d was Thermoanaerobacter sp. Optimum growth temperature , pH and concentration of NaCl were 65℃, 7.5 and 2% seperately,products of D-xylose were alcohol, acetic acid, CO2, and a small number of isobutanol and propionic acid. In the optimum growth conditions, xylose degradation rates reached to 91.37%. Strain xyl-d was extremely thermophilic, high xylose conversion, acidotolerant anaerobe. It was a potential bacteria that can be used for consolidated bioprocessing. 6) MH5 belonged to Porphyromonadaceae, optimum growth temperature , pH and concentration of NaCl were 35℃, 7.5 and 0% separately. Yeast extraction was degraded into acetic acid, propionic acid,isovaleric acid and bit of isobutanol and valeric acid. MH5 showed highest similarity of 16S rRNA with Proteiniphilum acetatigenesT about 94%. Strains of xyl-d and MH5 provide new resources to microbial resource pool.