Growth and toxin production of phomopsin A and ochratoxin A forming fungi under different storage conditions in a pea (Pisum sativum) model system

Abstract

Phomopsins are mycotoxins mainly infesting lupines, with phomopsin A (PHOA) being the main mycotoxin. PHOA is produced by Diaporthe toxica, formerly assigned as toxigenic Phomopsis leptostromiformis, causing infections in lupine plants and harvested seeds. However, Diaporthe species may also grow on other grain legumes, similar to Aspergillus westerdijkiae as an especially potent ochratoxin A (OTA) producer. Formation of PHOA and OTA was investigated on whole field peas as model system to assess fungal growth and toxin production at adverse storage conditions. Field pea samples were inoculated with the two fungal strains at two water activity (aw) values of 0.94 and 0.98 and three different levels of 30, 50, and 80% relative air humidity.After 14 days at an aw value of 0.98, the fungi produced 4.49 to 34.3 mg/kg PHOA and 1.44 to 3.35 g/kg OTA, respectively. Strains of D. toxica also tested showed higher PHOA concentrations of 28.3 to 32.4 mg/kg.D. toxica strains did not grow or produce PHOA at an aw values of 0.94, while A. westerdijkiae still showed growth and OTA production.Elevated water activity has a major impact both on OTA and, even more pronouncedly, on PHOA formation and thus, proper drying and storage of lupins as well as other grain legumes is crucial for product safety.

Transcriptome profiling reveals the underlying mechanism of grape post-harvest pathogen Penicillium olsonii against the metabolites of Bacillus velezensis

“…Moreover, the gene encoding the mycotoxin phomopsin A ( PHOA ) was down-regulated in P. olsonii after exposure to B. velezensis metabolites. PHOA is the primary toxin among the group of secondary metabolites formed by the fungus ( Kunz et al, 2022 ). Therefore, the down-regulation of PHOA in P. olsonii caused by B. velezensis metabolites is an additional indication of the potential of B. velezensis metabolites as an eco-compatible alternative to harmful chemical fungicides.…”

Comparative Assessment of Different Yeast Cell Wall-Based Mycotoxin Adsorbents Using a Model- and Bioassay-Based In Vitro Approach

“…However, their efficacy varies depending on different product compositions and mycotoxins types [ 18 , 22 , 23 , 24 , 25 , 26 ]. “Emerging mycotoxins”, which represent lesser-known or newer forms of mycotoxins (this currently includes toxins such as beauvericin, enniatins, moniliformin, alternariol, and phomopsins), have become a center of interest due to their occurrence and potential concerns for animal production systems [ 15 , 27 , 28 , 29 ]. With an evolving mycotoxin focus, adsorbent products are also being investigated for enhancing their adsorption efficacies [ 30 , 31 ] as well as improving and extending their specificity, which in turn requires new assessment methodologies to be carried out in a timely and cost-effective manner to characterize novel product attributes.…”

Pd nanoparticles decorated ultrathin 2D metal–organic framework nanosheets with enhanced peroxidase–mimic activity and colorimetric assay of glucose

“…Rapid detection of various compounds based on biosensors is essential in different elds including clinical diagnosis, agricultural product quality control, food safety and environmental monitoring. [1][2][3][4][5] In comparison with other analytical techniques depending on large instruments, biosensors have gained great attention due to their convenience. Natural enzymes as important bio-receptors or labels in biosensors are always expensive, due to the difficulty in their preparation and purication.…”