Method for Rapid Detection and Identification of Chaetomium and Evaluation of Resistance to Peracetic Acid

Abstract

In the beverage industry, peracetic acid has been increasingly used as a disinfectant for the filling machinery and environment due to merits of leaving no residue, it is safe for humans, and its antiseptic effect against fungi and endospores of bacteria. Recently, Chaetomium globosum and Chaetomium funicola were reported resistant to peracetic acid; however, little is known concerning the detail of peracetic acid resistance. Therefore, we assessed the peracetic acid resistance of the species of Chaetomium and related genera under identical conditions and made a thorough observation of the microstructure of their ascospores by transmission electron microscopy. The results of analyses revealed that C. globosum and C. funicola showed the high resistance to peracetic acid (a 1-D antiseptic effect after 900 s and 3-D antiseptic effect after 900 s) and had thick cell walls of ascospores that can impede the action mechanism of peracetic acid. We also developed specific primers to detect the C. globosum clade and identify C. funicola by using PCR to amplify the β-tubulin gene. PCR with the primer sets designed for C. globosum (Chae 4F/4R) and C. funicola (Cfu 2F/2R) amplified PCR products specific for the C. globosum clade and C. funicola, respectively. PCR with these two primer sets did not detect other fungi involved in food spoilage and environmental contamination. This detection and identification method is rapid and simple, with extremely high specificity.

Design of a species-specific PCR method for the detection of the heat-resistant fungi Talaromyces macrosporus and Talaromyces trachyspermus

“…C. globosum has reported resistance to peracetic acid, which is used in the sanitization of manufacturing environments in the food and beverage industry (Nakayama et al . ). P. digitatum is a fungal necrotroph that causes a common citrus postharvest disease known as green mould (Marcet‐Houben et al .…”

Characterization of soil fungal community associating with suppressive soil to Verticillium yellows disease of Chinese cabbage

“…However, morphologic characterization of the strain by comparing with those of reference species is still unclear. T. terricola has been known to morphologically and phylogenetically resemble Chaetomium (Nakayama et al., 2013). Morphologic elucidations, as well as further phylogenetical studies, are needed to define the taxonomical position of fungal strain S69.…”

Sterilization of food packaging by UV-C irradiation: Is Aspergillus brasiliensis ATCC 16404 the best target microorganism for industrial bio-validations?

“…-Talaromyces bacillisporus SSICA 10915, isolated from heat-treated blueberries; -Aspergillus montevidensis (≡ Eurotium montevidense) SSICA 28219, isolated from a milk-based spreadable cream; -Aspergillus brasiliensis ATCC 16404, the suggested reference microorganism for validating sanitization processes on packaging or filling machines of Class IV (VDMA, 2005); -Chaetomium globosum ATCC 6205, an ascospore-forming mycetes that proved resistant to other sanitizing agents such as peracetic acid (Nakayama et al, 2013;Sato and Takei, 2000;Scaramuzza et al, 2020a) and was supposedly resistant to UV-C light due to its pigmented spores.…”