Dithionite Reduction in the Presence of a Tetrapyrrole-containing Fraction From the Desulfoviridin of Desulfovihrio gigas

Abstract

Low-molecular-weight fractions obtained from the desulfoviridin of D. gigas and from the growth medium of Desul/ovibrio sp. 10455 promoted the reduction of sodium dithionite to sulphide in the presence of reduced methylviologen. These fractions contained a tetrapyrrole of the isobacteriochI orin type which was not complexed with iron, nor was it complexed with protein. The observations are discussed in relation to the function of sulphite reductases in the sulphate-reducing bacteria.