title: A novel hybrid dual-channel catalytic-biological sensor system for assessment of fruit quality.
abstract: The release of volatile ethylene and acetaldehyde characterizes the metabolic state and quality of fruit. We have designed and implemented a hybrid dual-channel catalytic-biological sensor system, which is able to quantify both volatiles in situ. This sensor system consists of a mammalian cell line engineered for constitutive expression of an Aspergillus nidulans-derived biosensor which triggers quantitative reporter gene expression in the presence of volatile acetaldehyde. Ethylene, oxidized to acetaldehyde using a Wacker-based process, can be quantified by the same transgenic sensor cell line. Differential profiling of reporter gene transcription by the sensor system revealed the relative concentrations of both volatile metabolites and enabled correct assessment of fruit quality as shown for fresh, old and rotten apples. Functional combination of catalytic processes with biosensor technology is able to precisely capture the metabolic state of food and may foster novel insight into biochemical food quality assessment as well as the design of synthetic control circuits detecting and preventing food spoilage.
authors.affiliation: Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058 Basel, Switzerland.
authors.forename: Wilfried
authors.initials: W
authors.lastname: Weber
authors.forename: Stefan
authors.initials: S
authors.lastname: Luzi
authors.forename: Maria
authors.initials: M
authors.lastname: Karlsson
authors.forename: Martin
authors.initials: M
authors.lastname: Fussenegger
mesh_terms: D000079:Acetaldehyde / Q000032:analysis; D001233:Aspergillus nidulans / Q000235:genetics; D015374:Biosensing Techniques / Q000379:methods*; D004268:DNA-Binding Proteins / Q000378:metabolism; D005030:Ethylenes / Q000032:analysis; D005504:Food Analysis / Q000379:methods*; D005638:Fruit / Q000737:chemistry*; D005656:Fungal Proteins / Q000378:metabolism; D027845:Malus / Q000737:chemistry*
chemical_list: C074202:ALCR protein, Aspergillus nidulans; D004268:DNA-Binding Proteins; D005030:Ethylenes; D005656:Fungal Proteins; C036216:ethylene; D000079:Acetaldehyde