Endophytic Fungus Alternaria Macrospora: A Promising and Eco-Friendly Source for Controlling Aedes Aegypti Larvae and for Bactericidal Use

作     者：Ragavendran, Chinnasamy Kamaraj, Chinnaperumal Devarajan, Natarajan Malafaia, Guilherme 

作者机构： Kattankulathur Tamil Nadu Chennai603203 India Natural Drug Research Laboratory Department of Biotechnology School of Biosciences Periyar University Tamil Nadu Salem636 011 India Laboratory of Toxicology Applied to the Environment Goiano Federal Institute Urutaí GO Brazil Post-Graduation Program in Conservation of Cerrado Natural Resources Goiano Federal Institute Urutaí GO Brazil Post-Graduation Program in Ecology Conservation and Biodiversity Federal University of Uberlândia MG Uberlândia Brazil Post-Graduation Program in Biotechnology and Biodiversity Federal University of Goiás GO Goiânia Brazil 

出 版 物：《SSRN》 

年 卷 期：2023年

核心收录：

主　　题：Metabolites 

摘      要：The present study assesses the metabolites of endophytic fungal isolates’ larvicidal and pupicidal activity on Aedes aegypti mosquito larvae. The isolates were confirmed by macroscopic, microscopic, and PCR using a universal internal transcribed spacer primer for the molecular identification of the isolated fungus at the species level. The isolated fungus was first tested for its ability to produce toxic compounds in A. aegpti larvae in the 1-4th instar. The secondary metabolites were evaluated in bioassays at different test concentrations (100-500 µg/mL) for each instar of determined mosquito larvae. The 1st to 4th instar larvae of A. aegypti were exposed to ethyl acetate extracts, which exhibited lethal concentrations that killed 50% of the exposed larvae (LC50 = 96.167, 131.370, 217.595, and 143.864 µg/mL and 90% of the exposed larvae (LC90 = 395.16, 483.692, 882.545, and 655.722 µg/mL). After 120 h of exposure, the ovicidal bioassay’s mean (%) was observed. A concentration-dependent pattern was found in the enzymatic level of acetylcholinesterase in 4th instar larvae exposed to fungal mycelial metabolites. Treating 500 µg/mL of mycelia, metabolites produced significant histopathological damage in the 4th instar mosquito larvae. The highest growth inhibition zones were observed during the antibacterial investigation of Alternaria macrospora metabolites against E. coli (22 mm) and S. aureus (20 mm). Also, the detected mycelium metabolites were tested for docking studies to identify their binding ability towards the E. coli FimH and S. aureus tyrosyl-RNA synthetase protein. The mycelium metabolites with different concentrations were further tested in the in-vivo zebrafish model to evaluate developmental toxicity. This is the first report on mosquito larvicidal and pupicidal activity of ethyl acetate metabolites produced by A. macrospora species. The study findings demonstrate that A. macrospora metabolites might be an ideal, cheap, small, and environmentally suitab