Elaboration of Microbial Risk Assessment by Using Single-Cell Analysis Techniques

Microbial control is indispensable for creating a safe, secure, healthy, and hygienic life for people around the world. In recent years, along with increased consciousness regarding safety and hygiene, as well as lifestyle diversity, the needs of individuals have changed greatly, thus novel quality design for microbiological safety of new and unique products is needed. Furthermore, for flexibly responding to stricter laws and regulations of individual countries, advanced microbiological control technology has become an absolute necessity.

An important key to technology development for microbial control is analysis of the essential nature of target microorganisms. Kao has been focusing on identification and discrimination of microorganisms resistant to antimicrobial constituents by using MALDI-TOF MS, environmental microbiome analysis with next generation sequencers, visualization of target microorganisms with confocal laser scanning microscopy, and single-cell analysis of microbial dynamic behaviors.

An example is a study that applied single-cell analysis. It is known that some oily ingredients and powder materials reduce the effectiveness of preservatives, which are necessary to protect products from microbial contamination throughout the product life cycle. Some plant extracts can largely decrease preservative efficacy, depending on the kind and amount used. Time-lapse observations of microbial behavior in formulations containing plant extracts showed a phenomenon in which the number of proliferating cells was larger than that of killed cells, indicating that plant extracts stimulated microbial growth, thus consequently reduced preservative efficacy. Based on this finding, we supplemented a non-preservative material that can prevent microbial growth, which resulted in significant improvement of preservative efficacy.

Kao will continue to strive to improve technology for protecting individuals and the environment with advanced products.