Ocean Methane
Is methylphosphonate a natural product? If it is, then its catabolism by microrganisms seeking phosphorus might explain the ubiquity of methane in the oceans. Anaerobic Archaea, so far, are the only significant source of methane known. Thus,
Metcalf
et al.
(p.
1104
) looked for evidence of methylphosphonate biochemistry in the widespread archaeon
Nitrosopumilus maritimus.
The organism can synthesize C-P bonds using phosphoenolpyruvate mutase. By using its gene,
ppm
, as a marker, a possible phosphonate biosynthesis gene cluster was identified, and adjacent to this a gene for a cupin was found. Together with Fe(II) and O
2
the cupin catalyzed the production of methylphosphonate and formate. Homologs of the cupin gene are found in a wide range of common marine microbes, including
Pelagibacter ubique
and
Prochlorococcus.
海洋甲烷 甲基膦酸盐是一种自然产物吗?如果是,那么微生物通过分解甲基膦酸盐以寻找磷,可能解释了海洋中甲烷的普遍存在。到目前为止,厌氧古菌是已知的唯一重要甲烷来源。因此,Metcalf等人(第337卷,第1104页)在广泛存在的古菌Nitrosopumilus maritimus中寻找了甲基膦酸盐生物化学的证据。该生物可以使用磷酸烯醇丙酮酸异构酶合成C-P键。通过使用其基因ppm作为标记,可能的膦酸盐生物合成基因簇被鉴定出来,并且在此基因簇旁边发现了一个杯状蛋白基因。与Fe(II)和O2一起,杯状蛋白催化了甲基膦酸盐和甲酸的产生。杯状蛋白基因的同源物在广泛存在的海洋微生物中发现,包括Pelagibacter ubique和Prochlorococcus。