Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of polypeptides from Bacteroides melaninogenicus.

Abstract

Sodium dodecyl sulphate‐polyacrylamide gel electrophoresis has been applied to proteins extracted from 32 strains of Bacteroides melaninogenicus. Strains of subspecies melaninogenicus gave similar electrophoretic patterns which differed from those of strains outside the subspecies. Strains of subspecies intermedius serotype C were similar to one another in electrophoretic pattern, and were different from strains outside the subspecies and from one strain of subspecies intermedius of serotype C1. Greater variation was observed between asaccharolytic than between saccharolytic strains. The group within subspecies asaccharolyticus with low G + C content stained poorly and showed few bands. The group within subspecies asaccharolyticus with high G + C content showed interstrain differences but none would be confused with strains of the saccharolytic subspecies. The strain that did not react with type B antiserum was electrophoretically different from those strains that did. The asaccharolytic Lev type strains form a separate group based on both electrophoretic and physiological criteria.