Amon, R. M.W.. Alfred-Wegener Institute, ramon@awi-bremerhaven.de
, . M.W.. ,

 
INTERACTION OF BACTERIAL GROWTH AND COMPOSITION OF FRESH DISSOLVED ORGANIC MATTER FROM AN ARCTIC ICE FLOE
 
Bacterial utilization of dissolved organic matter (DOM) presents an important process for mineralization and compositional changes of DOM in all aquatic environments. Only few studies have investigated the interaction of heterotrophic bacterial activity and the molecular composition of their natural substrate. This study presents data from a 10 day decomposition experiment with water harvested from an Arctic multi-year-ice floe, rich in freshly produced DOM. The fresh nature of DOM, indicated by an aldose yield of 22%, is ideal to follow compositional changes during bacterial DOM utilization. The 30% loss of dissolved organic carbon (DOC) and high leucine uptake rates of bacteria during the experiment hold the promise for significant changes in the molecular composition of DOM. Bacterial growth indicators will be presented along with data on oxygen and DOC consumption, nutrient dynamics, and concentrations of aldoses and amino acids. The initial aldose composition of ice-DOM resembled freshly produced DOM in diatom cultures. The study will give more insight in substrate preferences of bacteria growing on natural DOM. By comparing the aldose and amino acid composition of initial ice-DOM and post-decomposition DOM to natural DOM samples I hope to identify the compositional imprint heterotrophic bacteria leave behind on freshly produced DOM.
 
Day: Thursday, Feb. 4
Time: 08:30 - 08:45am
Location: Sweeney Center
 
Code: SS33TH0830S