D. flagrans is one of the most studied species for the biological control of gastrointestinal nematodes. Its high degree of development, ease of laboratory production and ability to pass through the gastrointestinal tract of animals are characteristics of interest for the use of this fungus in production animals (Ojeda Robertos et al., 2009).
Understanding the physiology of nematophagous fungi (NF) is necessary to comprehend their predatory capacity, as well as their response to different nutritional sources. Different nutrients can regulate the sporulation of fungi. The concentration of these nutrients in the culture media determines the quality and quantity of the fungus, encourages sporulation and prevents mycelial growth (Krishna, 2005).
Implementing biological control requires increasing chlamydospore production in the laboratory. Stimulating the formation of these resistance structures on a massive scale is possible by adding growth and sporulation inducers to the culture media (Sagüés et al., 2013), although there are also environmental signals that influence chlamydospore formation and are often species-specific (Lin and Heitman, 2005).
Diverse authors have reported the addition of different components to traditional culture media in order to promote the development of this fungus. Silva et al. (2016), evaluated chlamydospore production using by-products from the industry and different amounts of initial inoculum. Sagués et al. (2013), evaluated the addition of meso-inositol and Tween 80. Cuadrado Osorio et al. (2021), found sodium acetate and ammonium sulfate to be enhancing elements in the production of resistance structures. Santurio et al. (2009), focused on a biphasic production system. Other authors have evaluated the physical conditions of chlamydospore production, such as Blair and Biddle (2020), who evaluated fungal dehydration as a strategy to increase spore production by subjecting the fungus to periods of slow and rapid drying.
Mannitol functions as a metabolic precursor, participating in various biochemical pathways which can provide energy to the cell (Goh et al., 2009; Son et al., 2012), in addition to regulating osmotic balance and interacting with reactive oxygen species in cell membranes (Meena et al., 2015).
The aim of this study was twofold: first, to assess the efficacy of mannitol as an inducer of fungal development; and second, to investigate various cultivation conditions to determine if unfavorable temperature and humidity conditions could serve as stress factors leading to chlamydospore formation.
留言 (0)