FIG. 4.

Relationship between sodium chloride concentration (b) or pH (a) and growth rate when yeast extract and Fe(III)-citrate were provided as electron donor and acceptor, respectively. The borate concentration was 2 g/liter. The pH value was 9.6 for the determination of the pH optimum, and the salt concentration was 20 g/liter for the optimal pH determination. The error bars indicate standard deviations of duplicates. It should be noted that, when sodium chloride was not added, the medium still contained approximately 8 mM sodium from sodium carbonate.