Pearl Jam (IMAGE) DOE/Pacific Northwest National Laboratory Caption Pearl Jam -- Soluble uranium has been converted to solid uraninite (UO2), strung like tiny pearls along branching extracellular polymeric substance, a slime secreted by Shewanella bacteria. Credit PNNL Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.