The action of chemical disinfectants on bacteriophages for the lactic streptococci

The times needed for the complete inactivation of bacteriophages for the lactic streptococci by several chemical disinfectants in various strengths were determined. The phage preparations, consisting essentially of whey, contained the usual amounts of protein and lactose, so that the results obtained must be considered applicable only under the defined conditions. Hydrogen and hydroxyl ions were found to inactivate phage when they were present in sufficient concentration but their effects between pH. values of 4 and 7 were negligible over several days at room temperature. By far the most effective of the disinfectants were active chlorine and permanganate, which suggests that the inactivation of phage is most readily brought about by oxidation.