Third, the water was enriched with soluble ferrous iron, which would happen only if the organisms had converted ferric iron, which is insoluble, to the soluble ferrous form.

• 第三，水中富含可溶解的亚铁，只有当这种微生物将不能溶解的三价铁转化为可溶于水的亚铁形式时，才会发生这种情况。