Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99353, USA.
Microb Biotechnol. 2011 Jan;4(1):55-63. doi: 10.1111/j.1751-7915.2010.00194.x.
Monitoring the activity of target microorganisms during stimulated bioremediation is a key problem for the development of effective remediation strategies. At the US Department of Energy's Integrated Field Research Challenge (IFRC) site in Rifle, CO, the stimulation of Geobacter growth and activity via subsurface acetate addition leads to precipitation of U(VI) from groundwater as U(IV). Citrate synthase (gltA) is a key enzyme in Geobacter central metabolism that controls flux into the TCA cycle. Here, we utilize shotgun proteomic methods to demonstrate that the measurement of gltA peptides can be used to track Geobacter activity and strain evolution during in situ biostimulation. Abundances of conserved gltA peptides tracked Fe(III) reduction and changes in U(VI) concentrations during biostimulation, whereas changing patterns of unique peptide abundances between samples suggested sample-specific strain shifts within the Geobacter population. Abundances of unique peptides indicated potential differences at the strain level between Fe(III)-reducing populations stimulated during in situ biostimulation experiments conducted a year apart at the Rifle IFRC. These results offer a novel technique for the rapid screening of large numbers of proteomic samples for Geobacter species and will aid monitoring of subsurface bioremediation efforts that rely on metal reduction for desired outcomes.
在刺激生物修复过程中监测目标微生物的活性是开发有效修复策略的关键问题。在美国能源部综合现场研究挑战赛（IFRC）在科罗拉多州里弗尔的现场，通过地下添加乙酸刺激杆状菌的生长和活性会导致地下水中的 U(VI)沉淀为 U(IV)。柠檬酸合酶（gltA）是杆状菌中心代谢的关键酶，控制着进入 TCA 循环的通量。在这里，我们利用鸟枪法蛋白质组学方法证明，gltA 肽的测量可用于跟踪原位生物刺激过程中的杆状菌活性和菌株演变。保守的 gltA 肽的丰度跟踪了 Fe(III)还原和生物刺激过程中 U(VI)浓度的变化，而样品之间独特肽丰度的变化模式表明 Geobacter 种群内存在特定于样品的菌株转移。独特肽的丰度表明，在相隔一年的里弗尔 IFRC 原位生物刺激实验中，刺激的 Fe(III)还原种群在菌株水平上可能存在差异。这些结果为快速筛选大量杆状菌属的蛋白质组样品提供了一种新方法，并将有助于监测依赖金属还原的地下生物修复工作。
