Iodine is a biophilic element that is important for human health, both as an essential component of several thyroid hormones and, on the other hand, as a potential carcinogen in the form of radioiodine generated by anthropogenic nuclear activity. Iodine exists in multiple oxidation states (−1, 0, +1, +3, +5, and +7), primarily as molecular iodine (I₂), iodide (I⁻), iodate $\left({\mathrm{I}{\mathrm{O}}_3}^{-}\right)$, or organic iodine (org-I). The mobility of iodine in the environment is dependent on its speciation and a series of redox, complexation, sorption, precipitation, and microbial reactions. Over the last 15 years, there have been significant advances in iodine biogeochemistry, largely spurred by renewed interest in the fate of radioiodine in the environment. We review the biogeochemistry of iodine, with particular emphasis on the microbial processes responsible for volatilization, accumulation, oxidation, and reduction of iodine, as well as the exciting technological potential of these fascinating microorganisms and enzymes.

碘是一种对人体健康很重要的亲生物元素，既是几种甲状腺激素的必需成分，又是人为核活性产生的放射性碘形式的潜在致癌物。碘存在于多个氧化态（-1，0，+ 1，+ 3，+ 5，和+7），主要是由于分子碘（I ₂），碘化（I ^- ），碘$（{\mathrm{一世}{\mathrm{Ø}}_3}^{-}）$或有机碘（org-I）。碘在环境中的流动性取决于其形态以及一系列的氧化还原，络合，吸附，沉淀和微生物反应。在过去的15年中，碘生物地球化学取得了重大进展，很大程度上是由于人们对环境中放射性碘的命运重新产生了兴趣。我们回顾了碘的生物地球化学，尤其着重于负责碘的挥发，积累，氧化和还原的微生物过程，以及这些令人着迷的微生物和酶的令人兴奋的技术潜力。