The ‘catalase test’, with special reference to Acetobacter species

Abstract

Catalase tests made on cultures of 19 species of Acetobacter were always positive when growth was in the logarithmic phase, before production of acid had become pronounced. The same test sometimes gave a doubtful result and sometimes a negative result when made with older cultures of the same organisms. Both young cultures and older cultures (up to 14 days) of all the organisms gave positive reactions for catalase when CaCO3 was introduced as a buffer into the malt-extract medium on which the organisms subsequently were cultivated. Estimations were made of the relative amounts of catalase produced by authentic cultures of the following: A. aceti, A. acetosum, A. kuetzingianurn, A. pasteurianum, A. suboxydans, A. xylinum, A. gluconicum, A. ascendens, A. capsulatum, A. aceligenum, and A. turbidans. Since acid inactivates catalase it is recommended that cultures grown for this test should be developed in a buffered medium and should be incubated at the lowest point of the optimum temp. range for the organism under examination.