Volatile Organic Compounds of Endophytic Fungi and Biotechnological Applications

Abstract

Endophytic fungi live in symbiotic association with plants for at least part of their life. They are potential agents for the production of new and bioactive compounds, as well as for the use in agriculture, medicine and industry. Endophytic fungi produce Volatile Organic Compounds (VOCs), which are low molecular weight compounds that readily evaporate at normal temperatures and pressures. Fungi are not only capable of producing a wide variety of volatile compounds, they are also able to metabolize them and they have a great importance in chemical ecology. Mixtures of VOCs produced by endophytic fungi are mainly composed by alcohols, aldehydes, esters, aromatic and aliphatic hydrocarbons, terpenoids, nitrogen and sulfur compounds. They can be used in biotechnological applications such as biofuels, mycofumigation, alellochemicals, flavor in food and in the chemotaxonomic identification of fungi. The objective of this mini review was to perform a search in the literature on the endophytic fungi producing VOCs and their biotechnological potential. Fungos endofíticos vivem em associação simbiótica com plantas por pelo menos parte de sua vida. Apresentam potencial na produção de substâncias novas e bioativas, e na descoberta de agentes para uso de interesse agrícola, medicinal e industrial. Os fungos endofíticos são produtores de compostos orgânicos voláteis (COVs), que são compostos de baixo peso molecular que evaporam facilmente em temperaturas e pressões ambiente. Os fungos não são apenas capazes de criar uma grande variedade de compostos voláteis como também de metabolizá-los, e são de grande importância na ecologia química. As misturas de COVs produzidos por fungos endofíticos são compostas principalmente por álcoois, aldeídos, ésteres, aromáticos, hidrocarbonetos alifáticos, terpenoides e compostos contendo nitrogênio e enxofre. Podem ser usados em aplicações biotecnológicas como biocombustíveis, agentes de micofumigação, agentes aleloquímicos, flavorizantes em alimentos e na identificação quimiotaxonômica de fungos. O objetivo desta mini revisão foi realizar uma busca na literatura sobre os fungos endofíticos produtores de COVs e seus potenciais biotecnológicos.

Cactus Endophytic Fungi and Bioprospecting for their Enzymes and Bioactive Molecules: A Systematic Review

“…Other VOCs isolated from endophytic fungi are used for biotechnological applications such as: (i) control of other microorganisms, (ii) biofuels (Mycodisel), since fungi produce several hydrocarbons, (iii) allelochemicals (due to their ability to inhibit seed germination or interfere with seedling development, acting as efficient bioherbicides and bioinsecticides), (iv) fungal flavourings (used in foods as flavouring agents) and (v) chemotaxonomy, since the compounds produced may allow identification and differentiation of fungal species [28] …”

“…Other VOCs isolated from endophytic fungi are used for biotechnological applications such as: (i) control of other microorganisms, (ii) biofuels (Mycodisel), since fungi produce several hydrocarbons, (iii) allelochemicals (due to their ability to inhibit seed germination or interfere with seedling development, acting as efficient bioherbicides and bioinsecticides), (iv) fungal flavourings (used in foods as flavouring agents) and (v) chemotaxonomy, since the compounds produced may allow identification and differentiation of fungal species. [28] Ortega et al [8] performed a biotechnological prospection of endophytes in the Patents database, but no patents using bioactive compounds isolated from cactus endophytic fungi were retrieved. Nevertheless, 185 registered patents indicate four areas of endophyte use: (i) use of the fungus to increase tolerance to abiotic stress and plant growth, (ii) biocontrol of herbivores and phytopathogens, (iii) bioremediation and phy-toremediation, and (iv) patents where the endophyte has more than one application.…”

“…[8,9,22] Among the secondary metabolites produced by endophytic fungi, alkaloids, terpenoids, steroids, isocoumarins, chromones and phenolics are the most reported and used in biotechnological processes. [25][26][27][28] The first study of endophytic fungi of cacti was carried out by Fisher et al [29] who studied Opuntia stricta in Australia and obtained 23 endophytic taxa. Subsequently, the richness of the endophytic mycobiome in cacti was extended by Suryanarayanan et al [30] who isolated 900 fungi from 22 Cactaceae species, with a focus on Cylindropuntia fulgida.…”

“…Endophytic fungi in plant tissues produce a wide range of secondary metabolites (including novel compounds) and enzymes that exhibit a variety of biological activities and have the potential to be used in food production, bioremediation of contaminated ecosystems, production of anticancer drugs, antibiotics, antivirals, anti‐inflammatories, antioxidants, insecticides, antifungals, and various other biotechnological applications in the pharmaceutical, cosmetic and agrochemical industries [8,9,22] . Among the secondary metabolites produced by endophytic fungi, alkaloids, terpenoids, steroids, isocoumarins, chromones and phenolics are the most reported and used in biotechnological processes [25–28] …”

Endophytic fungi: versatile partners for pest biocontrol, growth promotion, and climate change resilience in plants

“…Fungal endophytes can act as biocontrol agents by stimulating the plant's inherent defense molecules and defending themselves or by producing bioactive compounds with the ability to kill or prevent pathogen attacks on their own (Jaber and Araj, 2018;Huang et al, 2020). These bioactive compounds have antifungal and antibacterial properties and include terpenoids, flavonoids, alkaloids, quinols, chlorinated compounds, peptides, steroids, polyketides, phenols, and other VOCs (Moraes et al, 2020;Lu et al, 2021). As a result, several crop plants treated with EFs showed reductions in plant damage from a variety of plant diseases and plant-parasitic nematodes following effective colonization (Tables 2, 3).…”