Isolation of marine bacteria highly resistant to mercury and their bioaccumulation process

► A marine bacterium, strain S1, exhibiting a maximum Hg tolerance of 120 mg L−1 and a maximum Hg uptake capacity of 133 mg g−1, was isolated. ► Hg accumulation occurred at pH 4-10. ► The effect of co-ions depended on the ratio of remaining bioaccumulation capacity. ► Several functional groups contributed to Hg uptake and carboxyl groups were the most important.