Photosynthetic bacteria, acetate utilization

As the supply of energy-rich substrates diminished, the primitive photosynthetic cells no doubt developed photochemical reactions for storing more of the absorbed energy. A primeval ancestor of the acetate-utilizing photosynthetic bacteria may have evolved. Indeed, the central position in metabolism occupied by acetate may... 

The photosynthetic bacterium R. marinum A-501, which was considered to be the main (or only) H2 producer in BC1, could utilize various organic substrates for the photoproduction of H2 (Table 2). However, among the substrates tested, starch, cellobiose and acetic acid, which are utilized by BC1 as substrates for H2 production, could not be used for H2 production by a pure culture of strain A-501. The results indicate that the conversions of starch, cellobiose and acetic acid into H, require the contribution of other bacteria in BC1. Among the isolated strains, only V. fluvialis T-522 and T-59 possessed starch-degrading activity. This result suggests that V. fluvialis T-522 and T-59 contribute to the degradation of starch to supply some substrate(s) in a form that can be readily utilized by R. marinum A-501 for H2 production. 

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