An antimicrobial composition including an alkyl pyridinium or a salt of alkyl pyridinium and an isothiazolinone or a salt of an isothiazolinone is effective against bacterial and fungicidal growth and resulting degradation in paints, emulsions, adhesives, and joint compounds, among other things. The composition may be employed in an aqueous liquid medium. Carriers may be employed to deliver the antimicrobial mixtures in liquid or pellet form. The invention is also a method for inhibiting microbial growth which employs the antimicrobial composition.In a preferred aspect, the invention is antimicrobial composition which includes cetyl pyiridinium choride and benzisothiazolinone salt, in a proportion that is synergistically effective against Pseudomonas aeruginosa, Escherichia coli, Enterobacter aerogenes, and Alcaligenes faecailis.
