Transformation of Chlorobium limicola by a plasmid that confers the ability to utilize thiosulfate.

A modified transformation method for Chlorobium limicola confirms the role of an endogenous plasmid in thiosulfate metabolism. The plasmid was present in two forma specialis thiosulfatophilum (Tio+) strains and absent in one non-thiosulfate-utilizing (Tio-) strain. The plasmid (size, 14 kb) was transferred by transformation from Tio- to Tio+. The chromosomal restriction patterns, analyzed by pulsed-field gel electrophoresis, were used to distinguish between the different strains.