The synergy of ingredients should always be considered when formulating effective feed safety solutions. For example, the specific metabolic and absorption properties of different acids may affect other ingredients. Individual organic acids exert different properties and can have varying acidic values. The complexity of this situation demands a comprehensive, multi-action approach that is capable of defending against a range of mould species commonly found in feed and feed ingredients.
Category Director Feed Safety & Quality
Selko Feed Additives
Selko scientists and researchers at Westerdijk Fungal Biodiversity Institute in the Netherlands are shedding new light on the processes that inhibit mould in animal feed. Findings from their experiments explain how ActiProp, a synergistic proprietary combination of ingredients designed to curb microbial growth in feed, affects mould cell integrity. Researchers applied multiple biomechanistic models to examine the kinetics that can affect cells’ mitochondria and directly impact energy generation and other metabolic processes.
ActiProp treatment relies on a blend of different acids along with a buffering agent, moisture management and phytochemical components to deliver a broad-spectrum strategy for combatting moulds. The multi-year research collaboration conducted at one of the world’s largest biodiversity institutions confirms the antifungal mode of action used by Fylax® Forte-HC liquid with ActiProp® technology. Part of the Selko feed safety portfolio, the product works to inhibit mould growth in animal feed. Findings from the research were recently published in the International Journal of Food Microbiology.
REAL-WORLD CONDITIONS AND ADVANCED TECHNOLOGY UNCOVER NEW INSIGHTS
Microbial threats are an ever shifting and persistent threat in raw ingredients, feed production facilities and grain storage environments around the world. It is well-known that the presence of moisture is a risk factor for moulds to form and proliferate. In experiments conducted at Westerdijk Fungal Biodiversity Institute, scientists isolated Aspergillus chevalieri from moulded feed originating from different continents and countries. As a xerophilic mould, Aspergillus chevalieri can proliferate under low water activity (aW), and even when storage conditions meet a high grade of quality. Researchers developed an optimal growth model closely mimicking conditions commonly experienced in livestock settings, imposing a strong challenge for testing Fylax Forte-HC liquid with ActiProp technology.
Combining multiple models with advanced technologies, including the oCelloscope, allowed scientists to more deeply examine cellular activities compared to the commonly relied on models that primarily count colony forming units (CFUs). Thus, researchers were able to go beyond revealing the presence and prevalence of a mould to detail the mould’s growth kinetics, cell metabolism and development.
EXPLORING THE SYNERGIES UNDERLYING MOULD INHIBITION
The mode of action deployed by Fylax Forte-HC liquid with ActiProp relies on its synergistic and proprietary combination of ingredients. New insights also shed light on the potential cytomorphologic effects of the mould inhibitor, including how it disrupts the integrity of the mould’s cell wall. The findings also demonstrate the mould inhibitor’s effects on mitochondria directly related with energy generation and metabolic functions such as initiating and regulating apoptosis. This unique mode of action validates principles developers followed when developing and studying Fylax Forte-HC liquid with ActiProp.
While the anti-fungal properties of propionic acid have long been used as a preservation strategy for grain and animal feed production, applying a single acid may not be as economically viable as perceived. Additionally, the volatile nature of propionic acid means that its long-lasting effect may be compromised. Buffering is often used to support a more effective application, reduce the corrosive proprieties of propionic acid, and support safer handling. The synergy of ingredients should always be considered when formulating effective feed safety solutions. For example, the specific metabolic and absorption properties of different acids may affect other ingredients. Individual organic acids exert different properties and can have varying acidic values. The complexity of this situation demands a comprehensive, multi-action approach that is capable of defending against a range of mould species commonly found in feed and feed ingredients.
EMPLOYING THE MODELS TO EVALUATE EFFICACY
Applying the enhanced capabilities of new models, Selko and Westerdijk Fungal Biodiversity Institute researchers conducted a series of experiments that looked at how Fylax Forte-HC liquid with ActiProp affected germinating conidia, and subsequent germ tubes and hyphae. Light microscopy was used to count the colonies that developed. Fungal colonies from isolated conidia germination and growth were assessed for the different treatments using the oCelloscope.
Results showed that the survival and development of Aspergillus chevalieri conidia was significantly decreased in the presence of Fylax Forte-HC liquid with ActiProp compared to a control group. The antifungal blend was demonstrated to significantly reduce the ability of hyphae (fungal cells) to grow compared to a control group (table 1, figure 1).
Fluorescence live-dead staining conducted on hyphae showed the percentage of cells that were significantly stained after cells were exposed to the feed additive blend at two different concentrations, and a control group. Significantly more cells were damaged after incubation with the blend at both concentrations compared to the control (Table 2).
The studies validated the mode of action, showing that Actiprop can interfere with critical processes involved in energy production and ATP synthesis. Electron microscopical imagery of untreated and treated conidia showed the active ingredient’s ability to affect the cell membrane integrity and exert a disrupting effect particularly on the mitochondria, inhibiting spore germination, and growth.
THE JOURNEY TO ADVANCE FEED-TO-FOOD SAFETY CONTINUES
Improving understanding of the characterization and presence of specific mould species as well as cellular mechanisms and activities occurring in moulds around the world provides researchers with enhanced assurance that the model is relevant to the industry. The ability to isolate conidia in animal feed and study its metabolism kinetics, reflects Selko’s ongoing commitment to investing in innovation. Selko is delving deeper into kinetic studies and modelling as it expands its innovation pipeline. The use of cross-functional modelling and artificial intelligence will assist in enhancing the predictive capabilities used to steer feed safety efforts. Additional innovations are focusing on engineering applications. As today’s livestock producers and feel mills navigate global warming, stricter regulations on the use of fungicides, and myriad other challenges, these efforts will play a role in Selko’s purpose of Feeding the Future.
About Pedro Caramona
Pedro Caramona is currently the Category Director Feed Safety & Quality at Selko Feed additives. Caramona has received his animal science degree after his thesis on animal nutrition at Utah State University, USA. He has since been working in the feed additive industry for the past 17 years.
His experience comes from having active roles in management and technical support, sales, and R&D in the USA (California, Arizona) and across EMEA.
