Encapsulated Microbes for Recovering Soluble Rare Metals

Abstract

We have conducted research and development on encapsulated Shewanella bacteria with Morishita Jintan Co., Ltd. The Shewanella bacteria are able to separate and concentrate rare metals from dilute solutions into microbial cells. We have developed a new biomineralization system to reduce soluble palladium (II), platinum (IV), and gold (III) into insoluble metal nanoparticles. We also proposed a new biosorption system to separate soluble indium (III) or dysprosium (III) and concentrate it within microbial cells. Moreover, microbe-enclosed capsules were used as a simple method of introducing the Shewanella bacteria into the process solution during rare metal recovery. The use of encapsulated Shewanella bacteria is an effective way to facilitate efficient solid-liquid separation of bacterial cells containing rare metals. Our proposed recycling biotechnologies are linked to the development of low-cost and eco-friendly recycling processes that enable the low-energy and rapid recovery of rare metals from post-consumer products.