A serious consequence of marine biofouling on metallic structures is the insidious localized corrosion at the attachment sites of fouling organisms, such as barnacles. Albeit known, this phenomenon is poorly understood and currently mitigated using cost- and labor-intensive methods. In this work, we study the contribution to biofouling corrosion by a protein contained in the adhesive cement that barnacles secrete to attach to immersed substrates. We synthesize a specific cement protein of 20 kDa (CP20) from the barnacle Megabalanus rosa and study its corrosion behavior independently of the animal. Our results show that CP20 accelerates the corrosion rate of a marine-grade, mild steel from 0.7 to 1.6 mm year⁻¹. Through chemical analysis of the corrosion products, protein adsorption studies on the metal surface, and cyclic voltammetry, we elucidate an intricate corrosion mechanism that relies on the strong adhesive properties of CP20 and its electrochemically active disulfide groups. Our results have far-reaching implications on the prediction and mitigation of biocorrosion in marine applications. Moreover, the protein-induced corrosion mechanism unveiled in our study may be extended to other scenarios to understand the degradation of metal alloys used in food storage and biomedical implants.

海洋生物污垢对金属结构的严重后果是在污垢生物（如藤壶）的附着位点隐匿局部腐蚀。尽管已经知道，但是这种现象很少被理解，并且目前使用成本和劳动强度大的方法来减轻。在这项工作中，我们研究了藤壶分泌的黏附剂中所含的一种蛋白质对生物污垢腐蚀的贡献，藤壶分泌这种蛋白质附着在浸没的基质上。我们从藤壶Megabalanus rosa合成了20 kDa（CP20）的特定水泥蛋白，并独立于动物研究其腐蚀行为。我们的结果表明，CP20将海洋级低碳钢的腐蚀速率从0.7年提高到1.6毫米^-1。通过对腐蚀产物的化学分析，对金属表面蛋白质的吸附研究以及循环伏安法，我们阐明了复杂的腐蚀机理，该机理依赖于CP20及其电化学活性的二硫键基团的强粘附性。我们的结果对海洋应用中生物腐蚀的预测和缓解具有深远的影响。此外，在我们的研究中揭示的蛋白质诱导的腐蚀机制可能会扩展到其他情况，以了解用于食品存储和生物医学植入物的金属合金的降解。