Development of a compact stacked flatbed reactor with immobilized high-density bacteria for hydrogen production

We have developed a compact stacked flatbed reactor (CSFR) composed of several pieces of agar plates containing an H2H2-producing bacterium, Escherichia coli. The bacterium was immobilized at high density (8 mg dry cell/ml agar) in the flatbed agar plate with 1.5–2 mm in thickness, producing H2H2 under fermentative conditions. These flatbeds were vertically assembled to enable the easy extraction of products from the reactor. In batch reaction at 100 mM glucose as a starting substrate, more than 90% of glucose was consumed, resulting in the maximum H2H2-production rate of 6.7lH2/gdry cell/l reactor/h and total H2H2 yield of 1.2molH2/molglucose.