Since 5-chloro-2-methyl-4-isothiazolin-3-one (CMI) has a relatively wide antibacterial spectrum, and low toxicity to humans, it is widely used as a bactericide and fungicide, or a slime control agent for a cooling tower. The minimum inhibitory concentration of CMI for E. coli K-12 was 1.6 mg/l. Short-time (~45 min) exposure of E. coli K-12 to 20 mg/l CMI prolonged the lag phase of cell growth. On the other hand, a normal logarithmic growth phase was observed after the lag phase. When E. coli K-12 was exposed to 1.0 mg/1 CMI for 25 h, the sterilization fraction reached 99%. A CMI concentration of more than 10 mg/1 and an exposure time of more than 5 h were required for attaining a 99.9% sterilizing fraction. The antibacterial activity of CMI against E. coli K-12 cells embedded in 0.6 % agar was high in the upper layer of the biofilm and low in the bottom layer of the biofilm. When activated sludge was supplied with artificial sewage with 20 mg/1 CMI, CMI-resistant bacteria became dominant in the bacterial consortia.

Subject
Films, Piping, Viability, Reactors, Adsorption, Pseudomonas aeruginosa, Biofilms, Incubation, Sludge, Bacteria, Biocides, Microbiologically influenced corrosion, Waste water
Keywords:
biocide, antibacterial activity, biofilm, diffusion
© 2004 Association for Materials Protection and Performance (AMPP). All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise) without the prior written permission of AMPP. Positions and opinions advanced in this work are those of the author(s) and not necessarily those of AMPP. Responsibility for the content of the work lies solely with the author(s).
2004
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.