Intracytoplasmic membrane vesiculation in light-harvesting mutants of Rhodobacter sphaeroides and Rhodobacter capsulatus

Mutant 19 of Rhodobacter sphaeroides as well as, mutant Ala+ of Rhodobacter capsulatus do not form B800-850 light-harvesting bacteriochlorophyll polypeptide complexes when growing with low aeration in the dark or anaerobically in the light. This is demonstrated on the basis of N-terminal amino acid analyses. Electron micrographs of thin sections of both mutant strains revealed the presence of regularly shaped ICM vesicles. The results show that ICM vesiculation is independent of the incorporation of B800-850 complexes.