Short note: extracellular export and consumption of glucose in Antarctic sea ice

Abstract Extracellular carbohydrate production is widespread in sea ice microbial communities, being produced by both algae and bacteria. Under stressful conditions, including nutrient limitation high light, cells may export excess fixed carbon as glucose. Glucose microsensors were used to measure extracellular glucose exudation consumption a algal community. increased with increasing irradiance between 15 512 µmol photons m −2 s −1 . This correlated declining F v values NPQ values, implying that resulted from exposure above optimal irradiances. concentrations samples treated DCMU block photosynthesis, declined at all Bacterial of was 6 34% per hour. There have been very few measurements DOC/glucose the data presented here make an important contribution our understanding processes.