Indigo-reducing Clostridium isatidis isolated from a variety of source,s including a 10th-century Viking dye vat

Clostridium isatidis, an endospore-forming, indigo-reducing bacterium recen tly isolated from a woad dye vat prepared according to traditional methods, was also isolated from enrichments prepared from a variety of other indigo -yielding plant materials, and from material interpreted as dyebath waste f rom 10th-century Anglo-Scandinavian (Viking) deposits (York, U.K.). Genotyp ic identity of the new isolates with the original isolate was demonstrated by 16S rRNA gene sequencing. It is concluded that C. isatidis was the organ ism responsible for indigo reduction in the woad vats of the past. Copyrigh t 2000 Academic Press