I’ve recently had the privilege of co-authoring a paper with Dr. Griselle Montenaz, and others, on the use of LuminUltra Technology Ltd’s QGO-M test method to screen aqueous polymer emulsions (APE) for microbial contamination. The paper describing the use of QGO-M XL measuring cellular adenosine triphosphate (cATP) in aqueous polymer emulsions (APE) has just been published in the journal: International Biodeterioration and Biodegradation (IBB; 114 (2016) 216-221; doi:10.1016/j.ibiod.2016.06.007). The procedure reported in the IBB paper reduces the time delay for microbiological contamination testing from the typical three to five days required for culture testing to less than 10 minutes. Currently, the cost of holding APE in quarantine while waiting for a microbiological clean rating is estimated to be in the hundreds of thousand dollars per year range for a single manufacturing facility. Additionally, the costs associated with spoiled APE batches can range from $50,000 to $250,000 per incident. The QGO-M XL method described in this paper essentially eliminates quarantine inventory time and increases the reliability of microbiological contamination testing..
The multi-year investigation was a collaborative effort of researchers at the Advanced Polymer Technology team at The Dow Chemical Company, Biodeterioration Control Associates, Inc., and LuminUltra Technologies, Ltd. Initial evaluations were run using a variety of APE that had been spiked with microbes that are known to be problematic to APE. In these studies, cATP concentrations were compared with culture test results. Successful detection and quantification of microbial contamination in laboratory samples set the stage for the second phase of the research effort. A total of 88 APE production run samples, including representative samples of 14 different types of APE, produced at 16 different production plants, were tested by QGO-M XL and standard plate count (SPC).
The traditional upper control limit for microbiological contamination in APE is ≤1,000 CFU mL-1. The investigation demonstrated that QGO-M XL’s sensitivity was substantially greater than that of the SPC method. The QGO-M LX test detected ≥100 cells mL-1 (»0.1 CFU mL-1), while the SPC protocol detected ≥10 CFU mL-1). Consequently, QGO-M XL provided more data about actual bioburdens in samples with ≤10 CFU mL-1. This additional information drives process improvement that reduces the risk of APE either being produced or shipped with unacceptably high microbial contamination. Additionally, because QGO-M XL can be run in the lab or in the field, the test can be used to identify microbial contamination sources after APE has been shipped. This improves APE product quality control for producers, transporters and users. The improved quality control has already translated into substantial cost savings for stakeholders who have adopted QGO-M XL for APE microbial quality control testing. For more information, contact me at fredp@biodeterioration-control.com.
