Untersuchungen zur Abtötungseffizienz der Persäuren Degaclean und Clarmarin und dem Katalase-Hemmer KH10 der Fa. Degussa gegen die beiden Quarantänebakterien Clavibacter michiganensis ssp. sepedonicus und Ralstonia solanacearum in wässeriger Suspension un

Ef_ciency surveys of the peracids Degaclean and Clarmarin in combination with the catalase inhibitor KH09 from the Degussa company for eradicating the two quarantine bacteria Clavibacter michiganensis ssp[ sepedonicus and Ralstonia solanacearum in an aqueous suspension and in the sewage water of the starch industry The e}ect of the two newly developed peracids "the percarbonic acid Clarmarin and the peracetic acid Degaclean# from the Degussa company was tested using 515 NIEPOLD the two quarantine bacteria Ralstonia solanacearum and Clavibacter michi`anensis ssp[ sepedonicus[ To obtain results for practical use\ the sewage water of a starch company in Germany which contained soil and potato tuber debris was used[ This population of micro!organ! isms that naturally occur in the sewage water was chosen as the standard to evaluate the conventional bactericidal compounds in comparison to the peracids[ It could be shown that the catalases of the micro!organisms caused tremendous activity losses of the peracids[ To inactivate these proteins\ the application of a catalase inhibitor "KH09# was necessary\ since the use of peracids alone required 19 999 ppm and a standard incubation time of 19 min[ With the combination of Clarmarin:KH09 "0 ] 0# in a concentration of 1999 ppm and the standard incu! bation time the indigenous microbial population could be destroyed\ whereas all other tested compounds\ including the conventional hydrogen peroxide {perhydrol| had only a small in~uence on the eradication rate[ In laboratory!scale experiments only 099 199 ppm of the Clarmarin:KH09 mixture and an incubation time of 0 1 min was required to absolutely destroy a cell suspension of 098 cells:ml of the two quarantine bacteriasuspended in an aqueous solution "Ringer#[ This result shows that the possibility now exists to e.ciently inter! rupt the infection cycle of quarantine bacteria if\ for example\ contaminated surface water is used for irrigat! ing potato _elds[ In addition to the very fast reaction with organic compounds of the Clarmarin:KH09 mix! ture\ there is a good environmental tolerability\ since both peracids disintegrate into water\ gaseous oxygen and easily degradable organic compounds[When adding the quarantine bacterium Ralstonia solanacearum as a rifampicin!resistant isolate at a concentration of 098 cells:ml into the sewage water of the German starch com! pany\ the bacterium could be destroyed by applying a concentration of 0999 ppm of the Clarmarin:KH09 mix! ture for 19 min[ By applying this small amount of the Clarmarin:KH09 mixture to the sewage water it has the advantage that not all indigenous micro!organisms are destroyed\ since they might be needed in the subsequent decomposition process of the sewage water[