Decomposition and synthesis of cozymase by bacteria

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Abstract
Cozymase at concns. of about 10-4 to 10-5 [image] was inactivated by streptococci, staphylococci, Escherichia coli, Proteus morganii and Hemophilus para-influenzae (but not by Lactobacillus arabinosus 17-5) at rates of 5 to 30 microg. / mg. dry wt. of cells / hr. at pH 6 to 7.5 and 37[degree]C. The initial concn. of coenzyme in staphylococic cells was 1 or 2 x 10-3 [image] or 0.1% of the cell wt. assuming 80% water. This was the form in which most of the nicotinic acid existed. Streptococci inactivated 4 x 10-4 [image] cozymase at the rate of 400 microg. mol./ mg./hr., and so inactivated their own dry wt. of the substance in 4 hr. Nicotinamide was produced from cozymase during its inactivation by streptococci. A nicotinamide derivative of V-factor (a group of factors any one of which will support the growth of H. parainfluenzae under certain conditions, including coenzymes I and II, desaminocoenzyme, and nicotinamide riboside) activity, such as the riboside, did not accumulate. The breakdown by H. parainfluenzae was similar. The breakdown in several bacteria was not greatly influenced by air (but was sometimes greater anaerobically), or glucose (this sometimes retarded it), and was still rapid at 10[degree]C. Streptococci were able to synthesize cozymase from nicotinic acid and adenylic acid in the presence of glucose; rates of +20 microg. mol./mg. dry wt./hr. were observed, which were about those required to account for the observed cell content of the substance.