Identification of Pseudomonas asiatica subsp. bavariensis str. JM1 as the first Nε-carboxy(m)ethyllysine-degrading soil bacterium

Research output: Contribution to journalResearch articleContributedpeer-review


  • Judith Mehler - , Ludwig Maximilian University of Munich (Author)
  • Kim Ina Behringer - , TUD Dresden University of Technology, Technical University of Braunschweig (Author)
  • Robert Ethan Rollins - , Ludwig Maximilian University of Munich (Author)
  • Friederike Pisarz - , Johannes Gutenberg University Mainz (Author)
  • Andreas Klingl - , Ludwig Maximilian University of Munich (Author)
  • Thomas Henle - , Chair of Food Chemistry (Author)
  • Ralf Heermann - , Johannes Gutenberg University Mainz (Author)
  • Noémie S. Becker - , Ludwig Maximilian University of Munich (Author)
  • Michael Hellwig - , Chair of Special Food Chemistry, Technical University of Braunschweig (Author)
  • Jürgen Lassak - , Ludwig Maximilian University of Munich (Author)


Thermal food processing leads to the formation of advanced glycation end products (AGE) such as Nε-carboxymethyllysine (CML). Accordingly, these non-canonical amino acids are an important part of the human diet. However, CML is only partially decomposed by our gut microbiota and up to 30% are excreted via faeces and, hence, enter the environment. In frame of this study, we isolated a soil bacterium that can grow on CML as well as its higher homologue Nε-carboxyethyllysine (CEL) as sole source of carbon. Bioinformatic analyses upon whole-genome sequencing revealed a subspecies of Pseudomonas asiatica, which we named ‘bavariensis’. We performed a metabolite screening of P. asiatica subsp. bavariensis str. JM1 grown either on CML or CEL and identified N-carboxymethylaminopentanoic acid and N-carboxyethylaminopentanoic acid respectively. We further detected α-aminoadipate as intermediate in the metabolism of CML. These reaction products suggest two routes of degradation: While CEL seems to be predominantly processed from the α-C-atom, decomposition of CML can also be initiated with cleavage of the carboxymethyl group and under the release of acetate. Thus, our study provides novel insights into the metabolism of two important AGEs and how these are processed by environmental bacteria.


Original languageEnglish
Pages (from-to)3229-3241
Number of pages13
JournalEnvironmental microbiology
Issue number7
Publication statusPublished - Jul 2022

External IDs

PubMed 35621031
ORCID /0000-0001-8528-6893/work/142256517



  • Bacteria/metabolism, Food Handling, Glycation End Products, Advanced/metabolism, Humans, Pseudomonas, Soil

Library keywords