Tuesday, October 18, 2011
PMEU toxicity test methods for environmental and industrial microbe control
PMEU Spectrion ® can be applied as a rapid tool for two types of biocide testing.
GROWTH PREVENTION TEST shows the ability of the biocides to prevent microbial growth in processes. Short detection times (typically under 10 hours) indicate poor or lacking effect of the active compound. Long detection times (over 10 hours) show that the biocide can prevent the microbial growth in the target.
This test can be performed in aerobic, microaerophilic or anaerobic conditions.
Temperature control of PMEU unit allows testing of psycrophilic, mesophilic and thermophilic microorganisms.
Turbidity of the test syringes, caused by microbial growth, will be documented automatically and growth curves will be drawn for every syringe. Detection time
(= the moment of the test, counted from the beginning, when the turbidity has increased by a certain factor) can be seen from these growth curves.
PMEU KILL TEST bases on the biocide-dependent change of microbial count. ATP Assay is the fastest method to detect the quantitative increase and the decrease of microbial cells in the samples and is therefore chosen to assist PMEU biocide testing in cases where both the growth prevention and the death of microbes shall be evaluated.
Results of these two types of biocide tests have a significant correlation.
GROWTH PREVENTION TEST can visualize some microbial processes which cannot be detected with traditional colony count method, eg. it shows the prevention of spore germination to vegetative cells by an effective biocide.
All PMEU Spectrion® methods have one excellent property: they indicate the effects of biocides in the original samples, and recovering effect of colony count methods are totally excluded. The user can focus the attention to the biocidic effects which really take place in the paper machine processes.
Modifications of PMEU biocide testing for biofilm control are also available.