It does not produce oxidase, coagulase, clumping factor, fibrinolysin, thermostable nuclease, tellurite reductase, gelatinase, protease, urease, arginine dihydrolase, alpha- or beta-haemeolysins, ornithine decarboxylase, acetyl-methylcarbinol or beta-galactosidase.
Today this phenomenon is explained by the overexpression and accumulation of the endogenous lysosomal beta-galactosidase specifically in senescent cells.