Heterotrophic growth of Thiobacillus A2 on sugars and organic acids.

Thiobacillus A2 grew on a number of organic acids, pentoses, hexoses and alpha-linked disaccharides, but not on beta-linked disaccharides or galactosides. Growth was slow on glucose, although fast-growing strains were selectively isolated. Additive growth rates occured on glucose and galactose; growth on glucose with fructose, pyruvate or gluconate was biphasic rather than diauxic; fructose was used preferentially over glucose; slow growth on glucose was accelerated by some disaccharides; growth on acetate, fumarate or succinate with glucose gave diauxic growth with preferential use of the acid and repression of glucose incorporation. Acetate and succinate tended to be used preferentially even with cultures grown on them in mixture with fructose or sucrose.