DeMoll E, Auffenberg T
Department of Microbiology and Immunology, Chandler Medical Center, University of Kentucky, Lexington 40536-0084.
J Bacteriol. 1993 Sep;175(18):5754-61. doi: 10.1128/jb.175.18.5754-5761.1993.
Methanococcus vannielii is capable of degrading purines to the extent that each of these purines may serve as the sole nitrogen source for growth. Results presented here demonstrate that purine degradation by M. vannielii is accomplished by a route similar to that described for clostridia. Various characteristics of the purine-degrading pathway of M. vannielii are described. Additionally, it is shown that M. vannielii does not extensively degrade exogenously supplied guanine if that compound is present at levels near or lower than those required to supply the cellular guanine requirement. Under those conditions, M. vannielii incorporates the intact guanine molecule into its guanine nucleotide pool. The benefits of a purine-degrading pathway to methanogens are discussed.
万氏甲烷球菌能够将嘌呤降解到这样的程度，即这些嘌呤中的每一种都可以作为生长的唯一氮源。此处呈现的结果表明，万氏甲烷球菌的嘌呤降解是通过一条类似于梭菌所描述的途径完成的。描述了万氏甲烷球菌嘌呤降解途径的各种特征。此外，研究表明，如果外源提供的鸟嘌呤的含量接近或低于满足细胞对鸟嘌呤需求所需的水平，万氏甲烷球菌不会大量降解它。在这些条件下，万氏甲烷球菌将完整的鸟嘌呤分子纳入其鸟嘌呤核苷酸池中。讨论了嘌呤降解途径对产甲烷菌的益处。
