Amino sugar-specific delta13C analysis for determining the formation and use of microbial residues

通过高效阴离子交换色谱（HPAEC）与荧光检测（FL）测量氨基糖的可用方法被调整为用同位素比质谱仪测量13 C/12 C比。然后，这种新的方法进行了校准，并与目前用于测定氨基糖作为OPA衍生物在土壤和微生物中的反相HPLC方法进行了比较。在此基础上，本研究通过两个实验研究了微生物残体的形成和利用：（1）在不同微生物群落结构的土壤中，C4-蔗糖形成的微生物残体;（2）重复添加蔗糖后形成和利用的微生物残体。这些实验将有助于我们的知识，结合土壤微生物生物量中13 C/12 C比值的测定微生物产品的营业额。这两个实验的基本假设是，真菌（如底物衍生的真菌葡糖胺所示）和细菌（如底物衍生的胞壁酸所示）在不同的土壤和不同的基质质量中对氮限制的反应不同。

The available methodology for measuring amino sugars by high performance anion exchange chromatography (HPAEC) with fluorescence- detection (FL) was adjusted for measuring the 13C/12C ratio with an isotope ratio mass spectrometer. Then, this new method was calibrated and compared with a reversed-phase HPLC method currently used for determining amino sugars as OPA-derivatives in soils and microorganisms. On the basis of this knowledge, two experiments will be carried out to investigate the formation and use of microbial residues by amino sugar-specific δ13C analysis: (1) Microbial residues formed from C4-sucrose in soils differing in their microbial community structure, (2) microbial residues formed and used after repeated sucrose additions. These experiments will contribute to our knowledge on the turnover of microbial products in combination with the determination of 13C/12C ratio in the soil microbial biomass. The underlying hypothesis of the two experiments is that fungi (as indicated by substrate-derived fungal glucosamine) and bacteria (as indicated by substrate-derived muramic acid) react differently to N Limitation in different soils and different substrate quality.