Soil invertebrates and the degradation of vanillin,cinnamic acid,and lignins

A range of 8–25% of fed cinnamic 2-[¹⁴C] acid and 9–14% of injected vanillin 5-[¹⁴C] were oxidised to ¹⁴CO₂ at 15 C over 7 and 6 days respectively in an isopod, Oiuscus asellus; a millipede, Pseudopolydesmus serratus; a slug, Deroceras reticulatum; a snail, Oxychilus draparnaldi; and an earthworm, Eisenia foetida. Approximately 2–10% of nonmetabolised and 13–48%, of metabolised vanillin were present in the animal tissues after 6 days. Correspondingly. 1–4% and 22–66% of these materials were found in egesta.A millipede (Oxidus gracilis), O. asellus. D. reticuluttum. O. draparnaldi, and E. foetida were found unable to degrade ring [¹⁴C]-, methoxy [¹⁴C]- and side chain [¹⁴C]-lignin to ¹⁴CO₂ over 10 days, thus providing very strong evidence that these invertebrates are incapable of degrading liginin.