二苯并噻吩降解菌筛选及16S rDNA序列分析

以DBT(dibenzothiophene,二苯并噻吩)为模型化合物,分离得到了一株能降解DBT的微生物HB2,应用HPLC对其脱硫特性进行了检测。应用PCR技术克隆到16SrDNA片段,核苷酸序列分析结果表明,该菌的16SrDNA全序列与假单胞菌存在98%的同源性,初步确定该菌在微生物系统发育学上的地位。     

Effects of nicotinamide and riboflavin on the biodesulfurization activity of dibenzothiophene by Rhodococcus erythropolis USTB-03

Rhodococcus erythropolis USTB-03 is a promising bacterial strain for the biodesulfurization of dibenzothiophene (DBT) via a sulfurspecific pathway in which DBT is converted to 2-hydroxybiphenyl (2HBP) as an end product. The effects of nicotinamide and riboflavin on the sulfur specific activity (SA) of DBT biodesulfurization by R. erythropolis USTB-03 were investigated. Both nicotinamide and riboflavin were found to enhance the expression of SA, which was not previously reported. When R. erythropolis USTB-03 was grown on a medium containing nicotinamide of 10. 0 mmol or riboflavin of 50. 0 μnol, SA was raised from 68. 0 or so to more than 130 mmol 2HBP/(kg dry cells. h). When R. erythropolis USTB-03 was grown in the presence of both nicotinamide of 5. 0 mmol and riboflavin of 25. 0 μmol, SA was further increased to 159. 0 mmol 2HBP/(kg dry cells. h). It is suggested that the biological synthesis of reduced form of flavin mononucleotide (FMNH2), an essential coenzyme for the activities of biodesulfurization enzyme Dsz C and A, might be enhanced by nicotinamide and riboflavin, which was responsible for the increased SA of R. erythropolis USTB-03.     

负载金属改性活性炭纤维的脱硫性能

采用浸渍法将金属负载到活性炭纤维(ACF)上对其进行改性,研究了负载金属改性ACF对模型油(二苯并噻吩-正辛烷)的吸附脱硫效果,对比了不同单金属和复合金属盐改性ACF的脱硫性能。实验结果表明:Ag和Zn复合改性的ACF具有最好的脱硫性能;在吸附温度为40℃,吸附时间为2.5 h,油剂质量比为21.5的优化条件下,脱硫率高达97.55%,且具有良好的重复利用性。     

Desulfurization of dibenzothiophene（DBT） by a novel strain Lysinibacillus sphaericus DMT-7 isolated from diesel contaminated soil

A new bacterial strain DMT-7 capable of selectively desulfurizing dibenzothiophene (DBT) was isolated from diesel contaminated soil. The DMT-7 was characterized and identified as Lysinibacillus sphaericus DMT-7 (NCBI GenBank Accession No. GQ496620) using 16S rDNA gene sequence analysis. The desulfurized product of DBT, 2-hydroxybiphenyl (2HBP), was identified and confirmed by high performance liquid chromatography analysis and gas chromatography-mass spectroscopy analysis respectively. The desulfurization kinetics revealed that DMT-7 started desulfurization of DBT into 2HBP after the lag phase of 24 hr, exponentially increasing the accumulation of 2HBP up to 15 days leading to approximately 60% desulfurization of the DBT. However, further growth resulted into DBT degradation. The induced culture of DMT-7 showed shorter lag phase of 6 hr and early onset of stationary phase within 10 days for desulfurization as compared to that of non-induced culture clearly indicating the inducibility of the desulfurization pathway of DMT-7. In addition, Lysinibacillus sphaericus DMT-7 also possess the ability to utilize broad range of substrates as sole source of sulfur such as benzothiophene, 3,4-benzo DBT, 4,6-dimethyl DBT, and 4,6-dibutyl DBT. Therefore, Lysinibacillus sphaericus DMT-7 could serve as model system for efficient biodesulfurization of diesel and petrol.     

不同硫源对红串红球菌生长和脱硫比活性的效应

本文牛磺酸、硫酸镁和二苯噻吩（ＤＢＴ）分别作为唯一硫源以及ＤＢＴ不同供给量对红串红球菌生长和脱硫比活性的效应进行了研究,结果表明,红串红球菌肯 利用有机和无机硫化合物作为硫源的能力。与牛磺酸和到镁相比,ＤＢＴ是促进红串红球菌生长和提高其脱硫比活红串红球菌的最大脱硫比活性达７９．１ｍｍｏｌ２ＨＢＰ．ｋｇ＾－１．ｈ＾－１。影响红串红球菌脱硫比活性的因素主要是其生长的不同阶段、ＤＢＴ供给量和羟基二苯生产     

固相微萃取-液相色谱法测定水中二苯并噻吩

分别采用高效液相色谱与固相微萃取-高效液相色谱法建立了水中微量二苯并噻吩的分析方法,结果表明固相微萃取对二苯并噻吩具有非常明显的富集作用。实验得到固相微萃取技术最佳检测条件为:吸附时间20min,解析时间3min,色谱流动相甲醇/水=90/10,方法的变异系数为2.85%,加标回收率102.4%,检测限0.03μg/mL。     

W/D152催化剂的制备及其对汽油中二苯并噻吩的催化氧化性能

采用浸渍法将钨负载在丙烯酸系弱酸性阳离子交换树脂D152上,制成了催化剂W/D152.实验研究了浸渍钨溶液p H值、温度、浓度等制备条件对催化氧化去除二苯并噻吩(DBT)活性的影响,并确定了催化剂的最佳制备条件.同时,运用红外光谱(FTIR)和环境电镜扫描(SEM)对W/D152的微观面貌进行了观察和分析.结果表明,在p H值为2.5,温度为30℃,2.5%(质量分数)的含钨溶液条件下制备的催化剂脱硫效果最佳;初始溶液含硫量为400 mg·kg-1,最高去除率达到99.1%,处理后样品的含硫量约为3.52 mg·kg-1,达到了总含硫量要求小于10mg·kg-1的欧五标准.催化剂表征结果表明,钨成功负载在树脂上,并形成一层薄层.W/D152催化剂循环使用7次后,处理后样品的含硫量仍可达到欧五标准.该催化剂催化氧化二苯并噻吩的反应符合一级动力学模型,速率常数为0.1091 min-1.     

Ni/Ce-Y沸石的制备及其对二苯并噻吩吸附研究

研究了负载二元金属NiCe-Y沸石的制备以及吸附二苯并噻吩的动力学性能。试验考察了二元金属Ni、Ce离子交换顺序、负载溶液方面对吸附剂制备的影响,初步得到了制备负载二元金属NiCe-Y吸附剂的优化条件。对NiCe-Y吸附剂进行脱硫性能评价及动力学分析,结果表明,负载二元金属NiCe-Y吸附剂比负载单一金属的Ni-Y吸附量提高31%,比Ce-Y吸附剂提高16%。     

生物脱硫技术用于清洁燃料生产的初步研究

从高硫油田筛选的红球菌Rhodococcus sp．FS-2可以通过专一性断裂C-S键的“4S”途径将二苯并噻吩（DBT）转化成2-羟基联苯，从而降低油品中的硫含量。利用该菌株对DBT和汽油、柴油的脱硫研究结果表明，FS-2菌株对DBT及柴油中的有机硫有良好的选择性脱除作用，而且脱硫前后的烃类组分基本没有改变。说明该菌的脱硫过程不会破坏燃料油的有效成分，可以用于燃料油的深度脱硫。     

施氏假单胞菌对二苯并噻吩的降解

从胜利油田油井附近土壤中筛选到 1 株施氏假单胞菌(Pseudomonas stutzeri UP1),可把二苯并噻吩(DBT)降解成水溶性硫化物,静息细胞实验证实该菌株细胞内存在能够降解DBT的酶系,降解过程的某些中间产物及终产物与已知的Kodama 路线相同,表明此菌株对DBT的降解是以 Kodama 路线进行的.