Evaluating changes to Ralstonia pickettii in high-purity water to guide selection of potential calibration materials for online water bioburden analyzers. (1st November 2019)

• Record Type: Journal Article
• Authors: Benkstein, Kurt D; Da Silva, Sandra M; Lin, Nancy J; Ripple, Dean C
• Is Part Of: Journal of industrial microbiology & biotechnology. Volume 46:Number 11(2019)
• Page Start: 1469
• Page End: 1478
• Publication Date: 2019-11-01
• Subjects: Ralstonia pickettii -- Online water bioburden analyzers -- Autofluorescence -- Viability -- High-purity water; Industrial microbiology -- Periodicals; 660.62
• DOI: 10.1007/s10295-019-02192-4
• Languages: English
• ISSNs: 1367-5435

Abstract

Abstract: Online water bioburden analyzers (OWBAs) can provide real-time feedback on viable bacteria in high-purity water (HPW) systems for pharmaceutical manufacturers. To calibrate and validate OWBAs, which detect bacteria using scattered light and bacterial autofluorescence, standards are needed that mimic the characteristics of bacteria in HPW. To guide selection of potential standards, e.g., fluorescent microspheres, a relevant bacterial contaminant, Ralstonia pickettii, was characterized for size, count, viability, and autofluorescence after exposure for 24 h to HPW or a nutrient environment. The cells exposed to HPW showed smaller sizes, with lower counts and autofluorescence intensities, but similar spectral features. The cell characteristics are discussed in comparison with a set of fluorescent microspheres, considering factors relevant to OWBAs. These studies suggest that fluorescent microspheres should be relatively small (< 1 µm diameter) and dim, while covering a broad emission range from ≈ (420 to 600) nm to best mimic the representative R. pickettii .