Development of a Taxon-Specific Real-Time Polymerase Chain Reaction Method to Detect Trichoderma reesei Contaminations in Fermentation Products

Abstract

Recently, a genetically modified microorganism (GMM) detection strategy using real-time PCR technology was developed to control fermentation products commercialized in the food and feed chain, allowing several unexpected GMM contaminations to be highlighted. Currently, only bacterial strains are targeted by this strategy. Given that fungal strains, like Trichoderma reesei, are also frequently used by the food industry to produce fermentation products, a novel real-time PCR method specific to this fungal species was developed and validated in this study to reinforce the GMM detection strategy. Designed to cover a sequence of 130 bp from the translation elongation factor alpha 1 (Tef1) gene of T. reesei, this real-time PCR method, namely TR, allows for the screening of commercial fermentation products contaminated with T. reesei, genetically modified or not, which is one of the major fungal species used as an industrial platform for the manufacturing of fermentation products. The developed real-time PCR TR method was assessed as specific and sensitive (LOD95% = eight copies). In addition, the developed real-time PCR TR method performance was confirmed to be in line with the “Minimum Performance Requirements for Analytical Methods of GMO Testing” of the European Network of GMO Laboratories. The validated real-time PCR TR method was also demonstrated to be applicable to commercial microbial fermentation products. Based on all these results, the novel real-time PCR TR method was assessed as valuable for strengthening the current GMM detection strategy regarding major fungal species used by the food industry to produce microbial fermentation products.