Eradication of Microbial Contamination in Metal Working Fluids

在许多制造工艺中，金属加工液用于确保降低刀具磨损和工件质量。据估计，全世界每年消耗超过5亿加仑的金属加工液。然而，微生物污染是这些液体降解的一个重要因素，导致设备生物污损和腐蚀，金属加工液降解，危及产品质量，并构成职业安全风险。一旦金属加工液被微生物污染，去除细菌是一项艰巨的任务。即使经过细致的清洁和充电程序，残留的细菌也会迅速繁殖。在工作流体系统的不可接近区域内的生物膜可能是清洁后快速再繁殖的原因。生物膜是一种附着在生物膜上的微生物群落，其功能依赖于复杂的社会相互作用。群体感应为生物膜细胞提供了交流和集体控制群体行为的手段。该奖项支持对抑制生物膜形成的群体淬灭策略的基础研究。研究结果可以帮助提高金属加工液的可持续性，减少浪费，并有助于限制职业暴露于潜在的致病菌栖息在金属加工液中。第一个研究目标是建立之间的关系的quorum quenching agent的浓度和该代理对生物膜根除的效力。一套群体猝灭剂（即，大黄素、酰化酶和α-淀粉酶）将在8行12列的测试矩阵中进行研究。浓度将从生产商建议的嗜盐微生物剂量开始变化。模型生物膜生物体（即，荧光假单胞菌和枯草芽孢杆菌）。 使用微板吸收光谱生物膜去除测定法，通过试剂对生物膜去除的最小抑制浓度来评价试剂对生物膜根除的功效。第二个研究目的是确定生物被膜根除的作用模式。 目前尚不清楚群体淬灭剂是否阻止表面上生物膜的初始建立，或者它们是否破坏并去除已经建立的生物膜。使用共聚焦激光显微镜以及Imaris和MetaMorph图像分析软件，将使用滴流反应器实时分析生物膜的形成和破坏。

In many manufacturing processes, metal working fluids are applied to ensure reduced tool wear and workpiece quality. Worldwide, more than half a billion gallons of metal working fluids are estimated to be consumed annually. However, microbial contamination is a significant factor in the degradation of these fluids, causing biofouling and corrosion of equipment, degradation of metal working fluids, imperilment of product quality, and posing occupational safety risks. Once metal working fluids are microbially contaminated, removing bacteria is a difficult task. Residual bacteria can quickly repopulate, even after meticulous cleaning and recharge procedures. Biofilms within the inaccessible regions of a working fluid system are likely responsible for the rapid post-cleaning repopulation. Biofilms are attached microbial communities whose function depends on complex social interactions. Quorum sensing provides the means for biofilm cells to communicate and collectively control group behavior. This award supports fundamental research on quorum quenching strategies to inhibit biofilm formation. Research results can help to increase the sustainability of metal working fluids, reduce waste, and help limit occupational exposure to potentially pathogenic bacteria inhabiting metal working fluids.The first research objective is to establish the relationship between the concentration of quorum quenching agent and the efficacy of the agent on biofilm eradication. A suite of quorum quenching agents (i.e., emodine, acylase, and a-amylase) will be studied in a testing matrix of eight rows and twelve columns. The concentration will be varied beginning with the manufacturer's suggested dosage for planktonic organisms. Model biofilm organisms (i.e., Pseudomonas fluorescens and Bacillus subtilis) grown in a metal working fluid will be used. The efficacy of an agent on biofilm eradication will be evaluated by the agent's minimal inhibition concentration for biofilm removal using a microplate absorption spectroscopy biofilm removal assay. The second research objective is to determine the action mode of biofilm eradication. It is unknown whether the quorum quenching agents prevent the initial establishment of biofilms on a surface or they disrupt and remove an already established biofilm. Using confocal laser microscopy and Imaris and MetaMorph image analysis software, biofilm formation and disruption will be analyzed in real-time using a drip flow reactor.