Cytochromes of Rhizobium japonicum 61A76 Bacteroids from Soybean Nodules

Abstract
Bacteroids of Rhizobium japonicum 61A76 were isolated from nodules of field-grown soybean plants by sucrose density gradient fractionation. The major cytochromes, aa3, b, c, and possibly o were present in the bacteroids throughout the active nitrogen-fixing life of the nodule. This is in contrast with previous reports using other R. japonicum strains in which cyotchromes aa3 and o were not found.