Growth of a lactate dehydrogenase deficient mutant of bacillus stearothermophilus in continuous culture

A lactate dehydrogenase deficient strain of B. stearothermophilus, lld-15, was outgrown by revertants to lactate production when cultivated in a chemostat at D = 0.25 h^?1 on a rich complex medium at a sucrose concentration of 2.5% (w/v) but was maintained without reversion at this dilution rate when the sucrose concentration was only 0.5% (w/v). In batch culture the revertant showed characteristics which distinguished it both from B. stearothermophilus strains lld-15 and NCA 1503.