To provide a series of techniques capable of producing isoprene from syngas or the like. Provided is a recombinant cell prepared by introducing a nucleic acid encoding isoprene synthase into a host cell having an isopentenyl diphosphate synthesis ability by a non-mevalonate pathway, wherein the nucleic acid is expressed in the host cell, and the recombinant cell is capable of producing isoprene from at least one C1 compound selected from the group consisting of carbon monoxide, carbon dioxide, formic acid, and methanol. As the host cell, a Clostridium bacterium or a Moorella bacterium is exemplified. Also provided is a method for producing isoprene using the recombinant cell.

Provided is a modified obligately anaerobic acetogen in which activity of at least one enzyme selected from the group consisting of a restriction enzyme, a modification enzyme, and a recognition enzyme constituting a type I restriction modification system enzyme is deleted or suppressed. Preferably, the activity of at least the restriction enzyme is deleted or suppressed. The obligately anaerobic acetogen is preferably a Clostridium bacterium or a Moorella bacterium, and particularly preferably Clostridium ljungdahlii.

Provided are CO hydratase and a method for producing formate using the same, and more specifically, to CO hydratase which is a novel enzyme which is produced by linking CO dehydrogenase (CODH) and CO.sub.2 reductase and can directly convert CO into formate, and use thereof.

Provided are CO hydratase and a method for producing formate using the same, and more specifically, to CO hydratase which is a novel enzyme which is produced by linking CO dehydrogenase (CODH) and CO.sub.2 reductase and can directly convert CO into formate, and use thereof.