REE pattern as a signature of bacterial activities

研究发现，不同菌种的稀土元素分布模式中均出现了重稀土元素的异常富集。该富集是由于多个磷酸盐络合物的络合作用引起的，随着pH的升高，由于羧酸中心的贡献较大，其贡献率降低。天然水体和前寒武纪带状氧化铁建造(BIF)中生物膜和生物铁氧化物的稀土配分模式具有相似的HREE富集型特征。这些结果表明，稀土配分模式中的HREE富集度可以作为自然系统和沉积记录中细菌活动的标志。

We found that anomalous enrichment of heavy rare earth elements (REE) was observed in REE distribution patterns on various bacterial species. The enrichment is caused by complexation with multiple phosphate complexes, the contribution of which decreased with the increase in pH due to the larger contribution of carboxylate site. Similar HREE enrichment characteristic was found for REE pattern of biofilm and biogenic iron oxides formed in natural waters and also in Precambrian banded iron oxide formation (BIF). These results showed that HREE enrichment in REE pattern can be a signature of bacterial activities in natural systems and in sedimentary records.