Differential acquisition of amino acid and peptide enantiomers within the soil microbial community and its implications for carbon and nitrogen cycling in soil
Differential acquisition of amino acid and peptide enantiomers within the soil microbial community and its implications for carbon and nitrogen cycling in soil
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DOI：
10.1016/j.soilbio.2015.05.003
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发表时间：
2015-09-01
影响因子：
9.7
通讯作者：
Jones, D. L.
中科院分区：
文献类型：
--
作者：
Broughton, R. C. I.;Newsham, K. K.;Jones, D. L.
L-异构氨基酸和寡肽被认为是植物和土壤微生物的关键氮源，绕过了吸收无机氮的需要，而含有肽聚糖的细菌内D-对映体的自循环可能会在氮循环中提供进一步的短路。在这里，我们使用稳定同位素谱（SIP）来确定土壤微生物群落中有机氮的命运。我们随后将C-13标记的D-或L-标记的氨基酸/肽掺入磷脂脂肪酸（PLFA）中。L-丙氨酸及其肽比D-对映体更快地被革兰氏阳性菌吸收，C-13掺入主要是与通常相关的反异构和异脂肪酸。革兰氏阳性菌。D-对映体的摄取被发现没有显着差异的微生物组之间，土壤细菌可能自我循环D-形式的氨基酸和肽的观点提供了很少的支持。肽链长度和掺入之间没有一致的关联。土壤溶液中L-和D-异构氨基酸的浓度分别为866 nM和72 nM。我们的结论是，革兰氏阳性菌似乎是L-对映体形式的氨基酸及其肽的主要竞争对手，但D-和L-对映体是细菌和真菌可用的N和C源。(C)2015年，作者。爱思唯尔有限公司出版
L-isomeric amino acids and oligopeptides are thought to represent a key nitrogen (N) source for plants and soil microorganisms, bypassing the need to take up inorganic N, whilst self-cycling of D-enantiomers within peptidoglycan-containing bacteria may provide a further short circuit within the N cycle. Here we use stable isotope profiling (SIP) to identify the fate of organic N within soil microbial communities. We followed the incorporation of C-13-labelled D- or L-labelled amino acids/peptides into phospholipid fatty acids (PLFAs). L-alanine and its peptides were taken up more rapidly than D-enantiomers by Gram-positive bacteria with C-13 incorporation being predominantly into anteiso- and iso-fatty acids typically associated with. Gram-positive bacteria. D-enantiomer uptake was found not to differ significantly between the microbial groups, providing little support for the view that soil bacteria may self-cycle D-forms of amino acids and peptides. There was no consistent association between peptide chain length and incorporation. The concentrations of L- and D-isomeric amino acids in soil solution were 866 nM and 72 nM, respectively. We conclude that Gram-positive bacteria appear to be the primary competitors for L-enantiomeric forms of amino acids and their peptides, but that both D- and L-enantiomers are available N and C sources for bacteria and fungi. (C) 2015 The Authors. Published by Elsevier Ltd.