Shepard Hawkins S, May Jody C, Zuniga Baltazar E, Abraham Joshua P, Pfleger Brian F, Young Jamey D, McLean John A
Department of Chemistry, Center for Innovative Technology, Vanderbilt University, Nashville, Tennessee 37235, United States.
Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37235, United States.
J Am Soc Mass Spectrom. 2025 Feb 5;36(2):400-408. doi: 10.1021/jasms.4c00459. Epub 2025 Jan 27.
Desorption electrospray ionization mass spectrometry imaging (DESI-MSI) provides direct analytical readouts of small molecules that can be used to characterize the metabolic phenotypes of genetically engineered bacteria. In an effort to accelerate the time frame associated with the screening of mutant libraries, we have developed a high-throughput DESI-MSI analytical workflow implementing a single raster line-scan strategy that facilitates the collection of location-resolved molecular information from engineered strains on a subminute time scale. Evaluation of this "Fast-Pass" DESI-MSI phenotyping workflow on analytical standards demonstrated the capability of acquiring full metabolic profiling information with a throughput of ∼40 s per sample. This Fast-Pass strategy was implemented in the analysis of genetically edited strains that have been engineered to produce various free-fatty acids (FFAs) for applications relevant to biofuels. Due to the untargeted nature of DESI-MSI, the investigation of these strains yielded molecular information for both global metabolites and targeted detection of accumulated bioproducts, allowing simultaneous readouts of strain-specific chemical profiles and comparative measurements of FFA production levels.
解吸电喷雾电离质谱成像（DESI-MSI）可提供小分子的直接分析读数，可用于表征基因工程细菌的代谢表型。为了加快与突变体文库筛选相关的时间框架，我们开发了一种高通量DESI-MSI分析工作流程，采用单光栅线扫描策略，有助于在亚分钟时间尺度上从工程菌株中收集位置分辨的分子信息。在分析标准品上对这种“快速通过”DESI-MSI表型分析工作流程的评估表明，能够以每个样品约40秒的通量获取完整的代谢谱信息。这种快速通过策略在对经过基因编辑的菌株的分析中得以实施，这些菌株经过工程改造可生产各种游离脂肪酸（FFA），用于与生物燃料相关的应用。由于DESI-MSI的非靶向性质，对这些菌株的研究产生了关于全局代谢物的分子信息以及对积累的生物产物的靶向检测，从而能够同时读出菌株特异性化学谱并比较FFA生产水平的测量值。
