Fourier transform ion cyclotron resonance mass spectrometry analysis

FT-ICR-MS (Bruker Daltonik GmbH, Bremen, Germany)


All used instruments and software for the Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) analysis were from Bruker Daltonik GmbH, Bremen, Germany. The measurements were performed on a solariX FT-ICR-MS with a 15 Tesla magnet system coupled with an Apollo II atmospheric pressure spray chamber. Negative electron spray ionization (ESI) mode was run for all samples.

FT-ICR-MS chromatogram
FT-ICR-MS chromatogram (M. Manecki)

The following parameters were set. Molecules occurred in less than 80 % of the samples were neglected. Only molecules with a mass to charge (m/z) ratio of 150 to 650 were considered. Allowed components within one molecule were: Cx; Hy; Oz<x; Ni<z; S1,2; P1( x, y, z, i = 1, 2, 3….). To avoid problems in the comparability between each single sample, everyone was standardized by the z-score method after the mentioned criteria were applied.

van Krevelin Plot example
van Krevelin Plot example (M. Manecki)

Results are indicated in van Krevelin Plots which are cross-plots of O/C and H/C ratios.

Amplicon pyrosequencing

Roche GS FLX
Roche GS FLX (D. Herlemann)


 The 16S rRNA gene sequences of 60 samples from the mesocosms were amplified using 30 cycles with the primers Bakt_341F and Bakt_805R. The primers were complemented with sample-specific 5-bp barcodes and sequenced  using Roche GS FLX titanium series chemistry.