Grassineau N V, Nisbet E G, Bickle M J, Fowler C M, Lowry D, Mattey D P, Abell P, Martin A
Department of Geology, Royal Holloway, University of London, Surrey, UK.
Proc Biol Sci. 2001 Jan 22;268(1463):113-9. doi: 10.1098/rspb.2000.1338.
Sulphur and carbon isotopic analyses on small samples of kerogens and sulphide minerals from biogenic and non-biogenic sediments of the 2.7 x 10(9) years(Ga)-old Belingwe Greenstone Belt (Zimbabwe) imply that a complex biological sulphur cycle was in operation. Sulphur isotopic compositions display a wider range of biological fractionation than hitherto reported from the Archaean. Carbon isotopic values in kerogen record fractionations characteristic of rubisco activity methanogenesis and methylotrophy and possibly anoxygenic photosynthesis. Carbon and sulphur isotopic fractionations have been interpreted in terms of metabolic processes in 2.7 Ga prokaryote mat communities, and indicate the operation of a diverse array of metabolic processes. The results are consistent with models of early molecular evolution derived from ribosomal RNA.
对来自津巴布韦27亿年（Ga）历史的贝林圭绿岩带生物成因和非生物成因沉积物中少量干酪根和硫化物矿物样本进行的硫和碳同位素分析表明，当时一个复杂的生物硫循环正在运行。硫同位素组成显示出比迄今从太古代报道的更广泛的生物分馏范围。干酪根中的碳同位素值记录了核酮糖-1,5-二磷酸羧化酶/加氧酶（rubisco）活性、甲烷生成和甲基营养作用以及可能的无氧光合作用的分馏特征。碳和硫同位素分馏已根据27亿年前原核生物席群落中的代谢过程进行了解释，并表明存在各种各样的代谢过程。这些结果与从核糖体RNA推导出来的早期分子进化模型一致。
