Functionalization of the model asphaltene 1-dodecylnaphthalene by Pseudomonas aeruginosa KK6 through subterminal metabolism
Functionalization of the model asphaltene 1-dodecylnaphthalene by Pseudomonas aeruginosa KK6 through subterminal metabolism
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DOI：
10.1016/j.petrol.2021.108870
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发表时间：
2021-10
影响因子：
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通讯作者：
Yuna Tomiyama;Toshihide Takeshita;Jiro F. Mori;R. Kanaly
中科院分区：
文献类型：
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作者：
Yuna Tomiyama;Toshihide Takeshita;Jiro F. Mori;R. Kanaly
重油中的沥青质化合物可以在石油改质和减轻污染的背景下进行生物功能化，但关于微生物使沥青质功能化的机理还存在知识空白。由于沥青质功能化研究的挑战，可能会使用由多芳烃中心和长链烷基链组成的模型沥青质化合物。本工作对一株鉴定为假单胞菌属铜绿假单胞菌KK6的土壤细菌进行了鉴定，发现该细菌能广泛生物转化水不溶性多环烷基芳烃模型沥青质，1-十二烷基萘(1-DDN)。采用气相色谱对1-DDN的转化进行定量，并采用高效液相色谱-紫外检测-电喷雾串联质谱仪(LC-UV/ESI-MS/MS)对转化产物进行分析。出现了一种不寻常的转化产物图谱，表明检测到不同烷基链长的化合物，每个不同的亚甲基单元与其多环芳香发色团相连。CID产物离子扫描分析表明，1-DDN被氧化、烷基链缩短、相对分子质量降低的1-萘基-烷酸和1-萘基-烷烃转化，结果解释支持KK6菌株通过亚端氧化机制生成这些化合物。在此基础上，构建了描述模型沥青质化合物生物功能化的生物转化途径。该菌株单独或与多环芳烃降解菌联合使用，可用于重油提质。
Asphaltenic compounds in heavy oils may be biologically functionalized in the contexts of oil upgrading and in mitigating contamination however there are knowledge gaps in regard to the mechanisms of asphaltene functionalization by microorganisms. Due to the challenges of studying asphaltene functionalization, model asphaltene compounds comprised of polyaromatic centers and long alkyl chains may be utilized. In this work, a soil bacterium identified asPseudomonasaeruginosaKK6 was characterized and it was found to extensively biotransform the water insoluble polycyclicn-alkylaromatic model asphaltene, 1-dodecylnaphthalene (1-DDN). Gas chromatography was utilized to quantify 1-DDN transformation and liquid chromatography with UV detection coupled to electrospray ionization tandem mass spectrometry (LC-UV/ESI-MS/MS) was used to analyze transformation products. An unusual transformation product profile occurred that showed that varying alkyl chain length compounds that differed by one methylene unit each were detected attached to their polycyclic aromatic chromophores. CID product ion scan analyses revealed that 1-DDN was transformed into oxidized, alkyl chain-shortened, reduced molecular weight 1-naphthyl-alkanoic acids and 1-naphthyl-alkanals and results interpretation supported that these compounds were produced through subterminal oxidation mechanisms by strain KK6. Based upon the results, biotransformation pathways that described the biological functionalization of a model asphaltene compound were constructed. On its own or in conjunction with polycyclic aromatic hydrocarbon-degrading bacteria, this strain may be applied to upgrading heavy oil.