Influence of barley malting operating parameters on T-2 and HT-2 toxinogenesis ofFusarium langsethiae, a worrying contaminant of malting barley in Europe

Abstract

The fungus Fusarium langsethiae, exclusively described in Europe at present, seems to have taken the place of other Fusarium species in barley fields over the last 5 years. It has proved to be a highly toxic type-A trichothecene producer (T-2 and HT-2 toxins). The aim of this work was to study the ecotoxinogenesis of this fungus the better to identify and manage the health risk it may pose during the beer manufacturing process. The influence of temperature and water activity on its growth rate and production of toxins are particularly assessed from a macroscopic point of view. Different cultures were grown on sterilized rehydrated barley with a water activity between 0.630 and 0.997 and a temperature ranging from 5 to 35 degrees C. Biomass specific to F. langsethiae and T-2 and HT-2 toxins were quantified by real-time polymerase chain reaction and liquid chromatography-mass spectrometry, respectively. It appears that the optimal temperature and water activity for F. langsethiae toxinogenesis are 28 degrees C and 0.997. This fungus was able to produce 2.22 g kg(-1) of these toxins in 16 days on barley in optimal production conditions. The malting process seems to be a critical step because, in its temperature range, specific production was six times higher than under optimal temperatures for fungus growth. In the short-term, this work will help redefine the process conditions for malting. In the medium-term, the results will contribute to the development of a molecular tool to diagnose the presence of this contaminant and the detection of the toxins in barley, from fields to the end product.

Fusarium langsethiae – a HT‐2 and T‐2 Toxins Producer that Needs More Attention

“…Medina and Magan (2010) reported that the optimum a w and temperature conditions for HT-2 and T-2 toxins production was between 0.980-0.995 and 20-30°C, respectively. This result is in agreement with other recent studies by Kokkonen et al (2010) and Strub et al (2010). Kokkonen et al (2010) showed that an a w of 0.994 and a temperature of 15°C favoured the type-A trichothecene production by F. langsethiae and F. sporotrichioides, while Strub et al (2010) reported an optimal temperature and a w for the fungus toxinogenesis as 28°C and 0.997, respectively.…”

“…() showed that an a w of 0.994 and a temperature of 15°C favoured the type‐A trichothecene production by F. langsethiae and F. sporotrichioides, while Strub et al. () reported an optimal temperature and a w for the fungus toxinogenesis as 28°C and 0.997, respectively. These observations imply that high levels of HT‐2 and T‐2 toxins are produced by F. langsethiae in the presence of high moisture on the crop, levels of which are influenced by ambient temperature in turn affecting fungal colonisation.…”

Changes in the Fusarium Head Blight Complex of Malting Barley in a Three-Year Field Experiment in Italy

“…These Authors hypothesized that this trend might be explained by the spread of F. poae , which is able to biosynthesize type A trichothecenes. Other Authors, have ascribed this phenomena to the presence of Fusarium langsethiae Torp & Nirenberg, another type A trichothecene producer [52], that in the last years increased its presence in Europe [53,54]. The absence of F. langsethiae in our investigations could be due to the isolation method used, which probably had a low efficiency for the detection of this slow growing species.…”

Control of T-2 Toxin in Fusarium Langsethiae and Geotrichum Candidum Co-Culture / Kontrola Toksina T-2 U Kokulturi Fusarium Langsethiae I Geotrichum Candidum

“…The presence of Fusarium langsethiae was detected in kernels of barley and other cereals in several countries in Europe (6,7). In fact, F. langsethiae has supplanted other species of Fusarium in the barley fi elds (8,9). F. langsethiae has been implicated in the production of high levels of T-2 and HT-2 toxins in cereals in Norway and other European countries (6,(10)(11)(12).…”