Polyamines as predominant organic basic compounds in the Antarctic Peninsula

Polyamines, such as putrescine, spermidine, and spermine, are vital for marine microorganisms as nutrients and bioactive compounds. While their presence has been studied in various marine regions, they remain unexamined in the Antarctic region, and no study has compared polyamines with monoamines, another class of organic nitrogen compounds. This study quantified polyamines and monoamines in seawater in the West Antarctic Peninsula region using 4-(N,N-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole (DBD-F) derivatization and HPLC-MS/MS. Polyamines were detected in Antarctica for the first time at sub-μM to μM levels, and it was approximately two orders of magnitude higher than reports from lower-latitude regions. Although total polyamine concentrations did not differ significantly among the five sites sampled, distinct patterns in polyamine composition were observed between the sites. In Wilhelmina Bay, total polyamines exhibited a positive but non-significant association with zooplankton backscatter (NASC), while cadaverine alone correlated significantly (r = 0.53, n = 15, p = 0.04). Our results established a baseline for Antarctic polyamines and revealed bay-to-bay differences in species composition. These baseline observations set the stage for tracking how polyamine dynamics respond to environmental change in the Southern Ocean.