二苯并噻吩脱硫菌的筛选及脱硫特性研究

发布时间：2018-04-12 13:07

  本文选题：生物脱硫 + 二苯并噻吩　； 参考：《中国石油大学(华东)》2015年硕士论文

【摘要】：二苯并噻吩及其衍生物是高硫原油的重要组成,它的存在不仅降低了原油品质,而且燃烧时排放二氧化硫,二氧化硫进入到外环境会造成环境质量的严重下降,并潜在威胁着生态系统及人体健康。本文以二苯并噻吩(DBT)作为模型化合物,从长期被石油污染的土壤中分离出专一性脱硫菌AS-21,采用16SrDNA序列法对菌株进行了鉴定,并对AS-21的培养条件和脱硫条件进行了优化;在此基础上,将AS-21接种到原油采出液中,考察该AS-21的脱硫效果;最后将AS-21制成休止细胞,考察不同浓度休止细胞的脱硫效果。本论文从不同油田区采集受污染的土样,进行初筛、复筛、分离纯化,得到两株脱硫菌AS-21和AS-26。该两株菌培养三天后,脱硫率分别达到73%和69%;脱硫菌AS-21为革兰氏阴性菌,且菌体为短杆形,对该菌株进行DNA提取,并经PCR扩增后测序,利用Blast程序将该菌的16SrDNA序列分析结果与GenBank中数据进行比对,比对结果显示该AS-21脱硫菌与红假单胞菌属Rhodopseudomonas 16SrDNA序列同源性最高,达到99%,故将AS-21初步鉴定为红假单胞菌属;通过对单因素影响研究和分析,得到菌株AS-21的最优培养条件和脱硫条件:培养温度为30℃,培养基初始pH为7.5,碳源为10g/L的甘油,氮源为2g/L的氯化铵,初始DBT浓度为100mg/L;通过响应曲面法研究确定生长温度为29.70℃,pH为7.43,DBT浓度为105.47mg/L时可得到最大脱硫率74%及最大菌株生长量2.49g/L;AS-21对采出液中所投放的DBT的脱硫实验结果表明,当向采出液中加入一系列营养物质后,脱硫率最高可为18.38%,由AS-21的生长曲线可知,0~15h为AS-21的生长停滞期,15~50h为AS-21的生长对数期,此后其生长进入稳定期,将对数末期的菌液制成休止细胞,对休止细胞脱硫效果进行考察,其脱硫率可达81%,高于普通菌株。
[Abstract]:Dibenzothiophene and its derivatives are important components of high-sulfur crude oil. Its existence not only reduces the quality of crude oil, but also emits sulfur dioxide during combustion.And potential threats to ecosystems and human health.In this paper, using dibenzothiophene (DBT) as a model compound, AS-21 was isolated from soil contaminated by petroleum for a long time. The strain was identified by 16SrDNA sequence method, and the culture conditions and desulfurization conditions of AS-21 were optimized.On this basis, AS-21 was inoculated into crude oil recovery solution to investigate the desulphurization effect of AS-21, and AS-21 was made into repose cells to investigate the desulphurization effect of different concentrations of resting cells.In this paper, the contaminated soil samples were collected from different oil fields, screened, screened, separated and purified, and two desulphurization bacteria AS-21 and AS-26 were obtained.After three days of culture, the desulphurization rates of the two strains reached 73% and 69%, respectively, and the desulphurization bacteria AS-21 was gram-negative, and the strain was short rod. The DNA was extracted and sequenced by PCR amplification.The results of 16SrDNA sequence analysis of this bacterium were compared with the data in GenBank by Blast program. The results showed that the homology of 16SrDNA sequence between AS-21 and Rhodopseudomonas 16SrDNA was the highest, which reached 99%, so AS-21 was preliminarily identified as Rhodopomonas.The optimum culture conditions and desulphurization conditions of the strain AS-21 were obtained through the study and analysis of the single factor: the culture temperature was 30 鈩，

本文编号：1739872