Tungsten (W) is a metal that is generally thought to be seldom used in biology. We show here that a W-containing oxidoreductase (WOR) family is diverse and widespread in the microbial world. Surprisingly, WORs, along with the tungstate-specific transporter Tup, are abundant in the human gut microbiome, which contains 24 phylogenetically distinct WOR types. Two model gut microbes containing six types of WOR and Tup were shown to assimilate W. Two of the WORs were natively purified and found to contain W. The enzymes catalyzed the conversion of toxic aldehydes to the corresponding acid, with one WOR carrying out an electron bifurcation reaction coupling aldehyde oxidation to the simultaneous reduction of NAD⁺ and of the redox protein ferredoxin. Such aldehydes are present in cooked foods and are produced as antimicrobials by gut microbiome metabolism. This aldehyde detoxification strategy is dependent on the availability of W to the microbe. The functions of other WORs in the gut microbiome that do not oxidize aldehydes remain unknown. W is generally beyond detection (<6 parts per billion) in common foods and at picomolar concentrations in drinking water, suggesting that W availability could limit some gut microbial functions and might be an overlooked micronutrient.

钨 (W) 是一种通常被认为在生物学中很少使用的金属。我们在这里展示了一个含 W 的氧化还原酶 (WOR) 家族在微生物世界中是多种多样且广泛存在的。令人惊讶的是，WOR 以及钨酸盐特异性转运蛋白 Tup 在人类肠道微生物组中含量丰富，其中包含 24 种系统发育不同的 WOR 类型。两种含有六种 WOR 和 Tup 的模型肠道微生物被证明可以同化 W。其中两种 WOR 经过天然纯化，发现含有 W。这些酶催化有毒醛转化为相应的酸，其中一个 WOR 进行电子分岔反应耦合醛氧化同时还原 NAD ⁺和氧化还原蛋白铁氧还蛋白。此类醛类存在于熟食中，并通过肠道微生物群代谢作为抗菌剂产生。这种醛解毒策略取决于微生物对 W 的可用性。肠道微生物组中其他不氧化醛的 WOR 的功能仍然未知。W 在普通食物和饮用水中的浓度通常无法检测到（<6 ppb），这表明 W 的可用性可能会限制某些肠道微生物功能，并且可能是一种被忽视的微量营养素。