Phenyllactic Acid Produced by Geotrichum candidum Reduces Fusarium sporotrichioides and F. langsethiae Growth and T-2 Toxin Concentration

Abstract

Fusarium sporotrichioides and F. langsethiae are present in barley crops. Their toxic metabolites, mainly T-2 toxin, affect the quality and safety of raw material and final products such as beer. Therefore, it is crucial to reduce Fusarium spp. proliferation and T-2 toxin contamination during the brewing process. The addition of Geotrichum candidum has been previously demonstrated to reduce the proliferation of Fusarium spp. and the production of toxic metabolites, but the mechanism of action is still not known. Thus, this study focuses on the elucidation of the interaction mechanism between G. candidum and Fusarium spp. in order to improve this bioprocess. First, over a period of 168 h, the co-culture kinetics showed an almost 90% reduction in T-2 toxin concentration, starting at 24 h. Second, sequential cultures lead to a reduction in Fusarium growth and T-2 toxin concentration. Simultaneously, it was demonstrated that G. candidum produces phenyllactic acid (PLA) at the early stages of growth, which could potentially be responsible for the reduction in Fusarium growth and T-2 toxin concentration. To prove the PLA effect, F. sporotrichioides and F. langsethiae were cultivated in PLA supplemented medium. The expected results were achieved with 0.3 g/L of PLA. These promising results contribute to a better understanding of the bioprocess, allowing its optimization at an up-scaled industrial level.

Water and temperature relations of Fusarium langsethiae strains and modelling of growth and T-2 and HT-2 mycotoxin production on oat-based matrices

“…The development of minimisation strategies has been difficult because these fungi produce no visible symptoms, and thus, contamination with toxins is challenging to discern. Currently, mitigation strategies to prevent T-2+ HT-2 J o u r n a l P r e -p r o o f Journal Pre-proof contamination in oats have been focused on pre-harvest agronomic practices (Bernhoft et al, 2012) and potential of inhibitory crop protection compounds post-harvest (Ferruz et al, 2016;Kawtharani et al, 2020). Thus, more detailed information is required on the impact of the relationship between key abiotic factors such as a w and temperature on both colonisation and production of T-2+HT-2 toxins.…”

The forgotten role of food cultures

“…and reducing the toxin concentration (Kawtharani et al . 2020 ). Since phenyllactic acid is produced by many LAB, it is often also naturally present in fermented foods and can be used in a variety of food products.…”

Statistical optimization of media composition and fermentation conditions for improved production of novel antimicrobial compound by Geotrichum candidum OMON-1

“…Geotrichum candidum is a lamentous yeast and the commonest species in the genus (Kawtharani et al 2020). It is an acid tolerant species and has been widely applied in cheese making where it confers proteolytic, lipolytic, amino acid catabolism as well as de-acidi cation activities in cheese, and traditional fermentation of milk.…”

“…Phenyllactic acid (PLA), indoleacetic acid (ILA) and phenylethyl alcohol (PEA) are three secondary metabolites that are produced from these species and have been documented as antimicrobial compounds. PLA and ILA initiate alterations in behavior and structure of L. monocytogenes thereby completely inhibiting its growth, while PEA on the other hand has been reported to enhance membrane damage and also inhibit RNA and protein synthesis (Kawtharani et al 2020). Of all the metabolites, PLA has been documented as the most effective natural antibiotic (Dieuleveux et al 1998a).…”