title: Spotlight on the Underdogs-An Analysis of Underrepresented Alternaria Mycotoxins Formed Depending on Varying Substrate, Time and Temperature Conditions.
abstract: Alternaria (A.)is a genus of widespread fungi capable of producing numerous, possibly health-endangeringAlternariatoxins (ATs), which are usually not the focus of attention. The formation of ATs depends on the species and complex interactions of various environmental factors and is not fully understood. In this study the influence of temperature (7 °C, 25 °C), substrate (rice, wheat kernels) and incubation time (4, 7, and 14 days) on the production of thirteen ATs and three sulfoconjugated ATs by three differentAlternariaisolates from the species groupsA. tenuissimaandA. infectoriawas determined. High-performance liquid chromatography coupled with tandem mass spectrometry was used for quantification. Under nearly all conditions, tenuazonic acid was the most extensively produced toxin. At 25 °C and with increasing incubation time all toxins were formed in high amounts by the twoA. tenuissimastrains on both substrates with comparable mycotoxin profiles. However, for some of the toxins, stagnation or a decrease in production was observed from day 7 to 14. As opposed to theA. tenuissimastrains, theA. infectoriastrain only produced low amounts of ATs, but high concentrations of stemphyltoxin III. The results provide an essential insight into the quantitative in vitro AT formation under different environmental conditions, potentially transferable to different field and storage conditions.
authors.affiliation: Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str 8-10, Berlin 10589, Germany. theresa.zwickel@bfr.bund.de.|Technische Universität München, Chair of Analytical Food Chemistry, Alte Akademie 10, Freising 85354, Germany. theresa.zwickel@bfr.bund.de.
authors.forename: Theresa
authors.initials: T
authors.lastname: Zwickel
authors.affiliation: Leibniz-Centre for Agricultural Landscape Research (ZALF), Institute of Landscape Biogeochemistry, Eberswalder Str. 84, Müncheberg 15374, Germany. sakahl@uni-potsdam.de.|University of Potsdam, Maulbeerallee 1, Potsdam 14469, Germany. sakahl@uni-potsdam.de.
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Kahl
authors.affiliation: Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str 8-10, Berlin 10589, Germany. horst.klaffke@bfr.bund.de.
authors.forename: Horst
authors.initials: H
authors.lastname: Klaffke
authors.affiliation: Technische Universität München, Chair of Analytical Food Chemistry, Alte Akademie 10, Freising 85354, Germany. michael.rychlik@tum.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Rychlik
authors.affiliation: Leibniz-Centre for Agricultural Landscape Research (ZALF), Institute of Landscape Biogeochemistry, Eberswalder Str. 84, Müncheberg 15374, Germany. mmueller@zalf.de.
authors.forename: Marina E H
authors.initials: ME
authors.lastname: Müller
mesh_terms: D000528:Alternaria / Q000302:isolation & purification / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D009183:Mycotoxins / Q000096:biosynthesis*; D053719:Tandem Mass Spectrometry; D013696:Temperature; D013997:Time Factors; D014908:Triticum / Q000382:microbiology
chemical_list: D009183:Mycotoxins
keywords: A. tenuissima; Alternaria infectoria; Alternaria toxin sulfates; HPLC-MS/MS; altenuic acid; altertoxins; modified Alternaria toxins; mycotoxin profile; rice; wheat