Entomopathogenic fungi (EPF) are microorganisms that cause fatal diseases of arthropods. The infection process involves several stages that consist of direct contact of the fungus with the surface of the cuticle of the attacked insect. The factors that determine the effectiveness of the infection process include lytic enzymes, secondary metabolites, and adhesins produced by EPF. Because of their high insecticidal effectiveness, these fungi are commonly used as biopesticides in organic farming. As the environment and farmlands are contaminated with many compounds of anthropogenic origin (e.g., pesticides), the effects of these toxic compounds on EPF and the mechanisms that affect their survival in such a toxic environment have been studied in recent years. This review presents information on the capacity of EPF to remove toxic contaminants, including alkylphenols, organotin compounds, synthetic estrogens, pesticides and hydrocarbons. Moreover, these fungi produce numerous secondary metabolites that can be potentially used in medicine or as antimicrobial agents. Despite their huge potential in biocontrol processes, the use of EPF has been underestimated due to a lack of knowledge on their abilities. In our work, we have presented the available data on the possibilities of the additional and unconventional use of these microorganisms.
In this study, the ability of 4-n-nonylphenol (4-n-NP) elimination by fungal species belonging to the genus Metarhizium was investigated. The occurrence of 35 metabolites from 4-n-NP degradation was confirmed. For the first time, based on the obtained results, the 4-n-NP biodegradation pathway distinctive for the genus Metarhizium was proposed. Principal Component Analysis (PCA) indicated that despite the similar elimination pathway in all the examined Metarhizium species, there are significant differences in the kinetics of degradation of 4-n-NP. Oxidation of the terminal methyl group of the aliphatic chain leading to the formation of carboxylic acids coupled with the removal of terminal carbon is characteristic of M. robertsii and M. guizhouense, whereas metabolites with a hydroxyl group in the distal part of the nonyl chain distinguish M. lepidiotae and M. majus. Additionally, this study verified the participation of cytochrome P450 in the elimination of the xenobiotic by Metarhizium as experimentally proven for M. robertsii.
Pyrethroids are chemical insecticides that are widely used to control pests. Entomopathogenic fungi are considered environmentally safe alternatives to these compounds. Pyrethroids and entomopathogenic fungi not only co-exist in the environment but can also be applied together in pest control. They are often found in contact with each other, and thus, it seems important to understand their interactions at the cellular level. In this study, we analyzed whether pyrethroids could influence the phospholipid profile of Beauveria bassiana and whether membrane changes are one of the mechanisms by which these fungi adapt to unfavorable environmental conditions. The results of our study revealed that pyrethroids changed the phospholipid profile and increased the cell membrane permeability of B. bassiana, which enabled them to enter and accumulate within the fungal cells, resulting in oxidative stress. Pyrethroids influenced the amount of neutral lipids, caused a decrease in sodium content, and also temporarily lowered the level of the secondary metabolite oosporein in the studied fungi. These findings indicate that the effect of pyrethroids on entomopathogenic fungi may be more complex than originally thought and that lipidomic studies can aid in fully understanding the influence of these chemicals on the mentioned group of fungi.
Metarhizium sp. are entomopathogenic fungi that inhabit the soil environment. Together, they act as natural pest control factors. In the natural environment, they come into contact with various anthropogenic pollutants, and sometimes, they are used together and interchangeably with chemical insecticides (e.g., neonicotinoids) for pest control. In most cases, the compatibility of entomopathogens with insecticides has been determined; however, the influence of these compounds on the metabolism of entomopathogenic fungi has not yet been studied. Secondary metabolites are very important factors that influence the fitness of the producers, playing important roles in the ability of these pathogens to successfully parasitize insects. In this study, for the first time, we focus on whether the insecticide present in the fungal growth environment affects secondary metabolism in fungi. The research revealed that acetamiprid at concentrations from 5 to 50 mg L−1 did not inhibit the growth of all tested Metarhizium sp.; however, it reduced the level of 19 produced destruxins in direct proportion to the dosage used. Furthermore, it was shown that acetamiprid accumulates not only in plant or animal tissues, but also in fungal cells. Despite the negative impact of acetamiprid on secondary metabolism, it was proofed to accumulate in Metarhizium spores, which appeared to have a stronger infectious potential against mealworm Tenebrio molitor, in comparison to the insecticide or the biological agent alone.
Metarhizium fungi, essential for ecosystem function and commonly utilised in pest control, often occupy ecological niches contaminated by toxic compounds of both anthropogenic and microbiological origin. The present study reveals the potential of Metarhizium anisopliae for biodegradation of the Fusarium mycotoxin zearalenone (ZEN), a common contaminant of crops that poses a significant threat to human and animal health due to its oestrogenic potential and toxicity. A key aspect of the pathway described is the degradation of ZEN by cleaving the lactone bond, which results in a significant reduction in mycotoxin toxicity, highlighting the fungus’s bioremediation potential. Furthermore, this study provides the first evidence of subsequent degradation of ZEN metabolites through progressive shortening of the aliphatic chain, primarily via alternating oxidation and demethylation, ultimately yielding trihydroxybenzene. Significantly, lactone bond cleavage occurred not only in ZEN itself but also in its reduced forms, the zearalanols, formed through the initial reduction of ZEN to zearalenols. Elevated mRNA levels of cytochrome P450 (CYP450) monooxygenases in M. anisopliae exposed to ZEN indicate their significant involvement in degradation mechanisms. Intriguingly, the inhibition of CYP450 activity resulted in a substantial shift in the quantitative ratio of α- and β-epimers of zearalenols and zearalanols. The observed alteration towards β-form production likely stems from the inhibition of other CYP450-dependent reactions, indirectly influencing ZEN reduction pathways—a particularly noteworthy finding. These insights are crucial for developing strategies to utilise M. anisopliae in the bioremediation of ZEN-contaminated areas.
Profesor Krzysztof Skotnicki jest cenionym i uznanym znawcą prawa konstytucyjnego, autorem licznych publikacji, nauczycielem akademickim, wychowawcą wielu pokoleń prawników. W roku 2023 mieliśmy zaszczyt i przyjemność świętować rocznicę siedemdziesięciolecia urodzin Pana Profesora. Święto to stało się okazją do uhonorowania Pana Profesora, czego wyrazem jest niniejsza publikacja. Księga dedykowana Panu Profesorowi, przygotowana została przez przyjaciół i współpracowników z polskich i zagranicznych ośrodków badawczych. Składa się z dwóch tomów, a ich struktura podyktowana została różnorodnością tematyczną tekstów nadesłanych przez ponad stu autorów. Artykuły poświęcone zostały podstawowym instytucjom ustrojowym i ich organom, demokracji, wolności, prawom człowieka i obywatela, prawu wyborczemu oraz sądownictwu. Odrębny rozdział stanowią teksty zagranicznych przyjaciół Pana Profesora opublikowane, w znacznej części, w ojczystym języku autorów. Życzymy Panu Profesorowi dalszych sukcesów!
About Me
PhD student in the Department of Industrial Microbiology and Biotechnology, University of Łódź, Poland
PhD student in the Department of Industrial Microbiology and Biotechnology, University of Łódź, Poland