Toxicity tests using the model organism Caenorhabditis elegans have shown that exposure to small microplastics such as polystyrene (PS) beads lead to high body burdens and dietary restrictions that in turn inhibit reproduction. Pharyngeal pumping is the key mechanism of C. elegans for governing the uptake of food and other particles and can be easily monitored by determining the pumping rates. In this study, pharyngeal pumping of C. elegans was examined in response to increasing quantities of food bacteria (E. coli: 10⁶–10¹⁰ cells ml^–1) and synthetic particles (10⁷–10⁹ beads ml^–1) of similar size (1 µm). While the average pumping rate of C. elegans exposed to E. coli depended on the density of the bacterial cells, this was not the case for the synthetic beads. At 10⁷ items ml⁻¹, bacterial cells and synthetic beads triggered a basic stimulation of the pumping rate, independent of the nutritional value of the particle. At quantities >10⁷ items ml^–1, however, the nutritional value was essential to maximize the pumping rate, as it was upregulated only by E. coli cells, which can be chemosensorially recognized by C. elegans. Given the unselective uptake of all particles in the size range of bacteria, restricting the pumping rates for particles with low nutritional value to a basic rate, prevents the nematodes from wasting energy by high-frequency pumping, but still allows a food-quality screening at low food levels.

使用模型线虫秀丽隐杆线虫的毒性测试表明，暴露于小的微塑料如聚苯乙烯（PS）珠粒会导致较高的身体负担和饮食限制，进而抑制繁殖。咽部抽水是线虫控制食物和其他颗粒摄入的关键机制，可以通过确定抽水率轻松监控。在这项研究中，检查了线虫的咽泵，以应对食物细菌（大肠杆菌：10 ⁶ –10 ¹⁰细胞ml ^–1）和合成颗粒（10 ⁷ –10 ⁹珠ml ^{–1）的增加}），尺寸类似（1 µm）。虽然暴露于大肠杆菌的秀丽隐杆线虫的平均泵吸速率取决于细菌细胞的密度，但合成珠粒却并非如此。在10 ⁷项目ml ^-1下，细菌细胞和合成珠引发了泵吸速率的基本刺激，而与颗粒的营养价值无关。数量> 10 ⁷毫升^–1时，营养价值对于最大程度地提高泵送速度至关重要，因为它仅被大肠杆菌细胞上调，而秀丽隐杆线虫可对其进行化学感应识别。。鉴于细菌大小范围内所有颗粒的非选择性吸收，将营养价值低的颗粒的泵送速率限制为基本速率，可防止线虫通过高频泵送浪费能量，但仍可在食物水平低。