Wang Jing, Zhang Xuwang, Fan Jiangli, Zhang Zhaojing, Ma Qiao, Peng Xiaojun
State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, China,
Appl Biochem Biotechnol. 2015 Jul;176(5):1263-76. doi: 10.1007/s12010-015-1644-9. Epub 2015 Apr 30.
In this study, two phenol-degrading bacterial strains, designated as PI1 and PI2, were isolated from activated sludge for the production of indigoids from indole. According to the 16S ribosomal RNA (rRNA) gene sequence analysis, strains PI1 and PI2 were identified as Pseudomonas sp. and Acinetobacter sp., respectively. Liquid chromatography/time-of-flight/mass spectrometry (LC/TOF/MS) was applied to analyze the metabolites during the biotransformation of indole by the phenol-degrading strains. The results indicated that both strains could catalyze the formation of four indigoids with the same prominent molecular ion (M-H)(-) peak at m/z 261.067 and molecular formula of C16H10N2O2, including indigo and a purple product, 2-(7-oxo-1H-indol-6(7H)-ylidene) indolin-3-one. Isatin and 7-hydroxyindole were detected as the intermediates. Thus, the possible pathways for the production of indigoids from indole were proposed. Subsequently, the optimal conditions for the production of indigo from indole were determined using response surface methodology, and 11.82 ± 0.30 and 17.19 ± 0.49 mg/L indigo were produced by strains PI1 and PI2, respectively. The present study should provide potential candidates for microbial production of indigoids.
在本研究中，从活性污泥中分离出两株苯酚降解细菌菌株，命名为PI1和PI2，用于从吲哚生产靛类化合物。根据16S核糖体RNA（rRNA）基因序列分析，菌株PI1和PI2分别被鉴定为假单胞菌属和不动杆菌属。应用液相色谱/飞行时间/质谱（LC/TOF/MS）分析苯酚降解菌株对吲哚进行生物转化过程中的代谢产物。结果表明，两株菌株均能催化形成四种靛类化合物，它们在m/z 261.067处具有相同的突出分子离子（M-H）（-）峰，分子式为C16H10N2O2，包括靛蓝和一种紫色产物2-（7-氧代-1H-吲哚-6（7H）-亚基）吲哚啉-3-酮。检测到异吲哚酮和7-羟基吲哚为中间体。因此，提出了从吲哚生产靛类化合物的可能途径。随后，采用响应面法确定了从吲哚生产靛蓝的最佳条件，菌株PI1和PI2分别产生了11.82±0.30和17.19±0.49mg/L的靛蓝。本研究应为微生物生产靛类化合物提供潜在的候选菌株。
