Abstract: A method of preventing the growth of microorganisms by contacting the microorganisms with a bioactive compound which may be described by one of the following formulas:H[(C.sub.n H.sub.2n) - A.sub.p - (C.sub.m H.sub.2m)CO].sub.k.sup.. NH C.sub.6 H.sub.4 SO.sub. 2 - CH = CH - X; ##SPC1##orR.sub.3 SO.sub.2 CH = CH - CONH.sub.2in which A is benzene or napthalene, X is --CN, --CONH.sub.2, --COOR, --SO.sub.2 R, --SO.sub.3 R, --NO.sub.2 or --COR, R.sub.1 is an amino, acylamido or nitro group, R.sub.2 is hydrogen or a lower alkyl group, R.sub.3 is an alkyl, substituted alkyl, aryl, substituted aryl, cycloalkyl, or substituted cycloalkyl or a heterocyclic group and where n = 0 to 18, m = 0 to 18, m + n = 24 or less, p = 0 or 1 and k = 0 or 1.