CONDITIONS FOR BACTERIOCHLOROPHYLL FORMATION AND THE ULTRASTRUCTURE OF A METHANOL-UTILIZING BACTERIUM, PROTAMINOBACTER-RUBER, CLASSIFIED AS NON-PHOTOSYNTHETIC BACTERIA

A methanol-utilizing bacterium, Protaminobacter rubel', formed a green pigment, when it was grown on 1,2-propanediol as a sole carbon and energy source. The pigment was identified as bacteriochlorophyll a by the absorption spectrum resembling the pigment from photosynthetic bacteria and by the exact stoichiometric relationship among the original pigment, the pigment treated to remove magnesium (bacteriopheophytin) and magnesium ion obtained from the pigment. Bacteriochlorophyll formation was stimulated by the exposure to light during the relatively early stage of the growth, while the continuous light exposure completely prevented the pigment formation. Aeration was also necessary for the pigment synthesis as well as the bacterial growth. Electron micrographs of thin section of P. ruber cells cultured in the intermittent light showed the probable existence of a chromatophore- like structure. © 1979 Taylor & Francis Group, LLC.