[Cytochrome pattern of methylotropic acetic acid bacterium MB 58 as dependent on growth conditions]

In contrast to methylotrophic bacteria investigated up to now the facultative methylotrophic Bacterium MB 58 (Acetobactersp. MB 58) does not possess a cytochrome aa3-complex, but we could find out cytochrome, cytochrome cco, cytochrome a1, and moreover cytochrome d in dependence on the growth conditions. Cytochrome d was found only in stationary phase of heterotrophic growth. Under methylotrophic growth conditions cytochrome d could be demonstrated only by lowering of the aeration rate during the fermentation, by variation the pH-value of the growth medium from 4.0 to 6.5 and with low growth rates (low dilution rates) during continuous fermentation. The addition of cyanide to the oxidized suspension of bacteria during the registration of the cytochrome-redox-difference spectrum allowed the selective representation of cytochrome d under all conditions even if no identification was possible in the spectrum normally. The oxidation of cytochrome d of Acetobacter sp. MB 58 in the presence of cyanide is an indication of its cyanide insensitivity. The low level of b-type cytochromes could be represented by a special technique for registration of spectra. In this connection a unknown absorption peak at 570 nm was registered. The cyanide insensitivity of cytochrome d from Acetobacter sp. MB 58 and the occurrence of several terminal oxidases is appreciated as a hint for a branched respiratory chain.