抄録
Cultural conditions suitable for bacteriochlorophyll a formation by Protaminobacter ruber classified as a non-photosynthetic bacterium were investigated. Optimal values for temperature, light intensity in the light followed by dark conditions, which was most suitable for bacteriochlorophyll formation, and apparent kLa were 20-25°C, ca. 2, 000 lux, and ca. 1.0 min-1, respectively. Although aeration was indispensable for the growth of P. ruber, less aeration was favorable for bacteriochlorophyll synthesis. In this microorganism, bacteriochlorophyll was inducibly formed under special conditions, while vitamin B12 and cytochrome were constitutively produced. In contrast, a photosynthetic bacterium, Rhodopseudomonas spheroides produced the highest amount of bacteriochlorophyll under continuous illumination conditions, which completely prevented bacteriochlorophyll formation in P. ruber, and also low oxygen tension conditions, under which P. ruber could not grow at all.
