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

• Applicant: Professor Dr. Rainer Georg Jörgensen
• Subject Area: Soil Sciences
• Term: from 2008 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 59081944

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.

• DFG Programme: Research Grants
• Major Instrumentation: Liquid Chromatographic system
• Instrumentation Group: 1380 Zubehör zur Chromatographie
• Participating Person: Dr. Jens Dyckmans