Cultivable cellulolytic fungi isolated from the gut of Amazonian aquatic insects

Abstract

Filamentous fungi have been targeted by bioprospecting studies because they are effective producers of extracellular enzymes that can potentially be used by the bioindustry. In this study, we isolated filamentous fungi from the guts of Amazonian aquatic insect larvae to evaluate their cellulolytic activity. We collected 69 larvae of shredder insects of three genera: Phylloicus (Trichoptera: Calamoceratidae), Triplectides (Trichoptera: Leptoceridae) and Stenochironomus (Diptera: Chironomidae) in ten streams from a protected area in the central Brazilian Amazon. Production of mycelia was elaborated in PDA (Potato Dextrose Agar) medium. The isolates were transferred to a synthetic medium with carboxymethyl cellulose, and Congo red was used to determine the enzymatic index. The hydrolysis halo, indicating the production of cellulases, was observed in 175 fungal isolates (70% of the total), of which 25 had an enzymatic index ≥ 2.0 and belonged to seven fungal genera. The fungal taxa Cladosporium, Gliocephalotrichum, Penicillium, Pestalotiopsis, Talaromyces, Trichoderma and Umbelopsis were isolated from guts of Phylloicus, Triplectides and Stenochironomus, which are traditionally used in biotechnological applications. Our results indicate the cellulolytic potential of fungi associated with the guts of aquatic Amazonian insects.

Host-Environment Interplay Shapes Fungal Diversity in Mosquitoes

“…The majority of these belong to the filamentous ascomycete genera Aspergillus , Beauveria , Cladosporium , Penicillium , and Trichoderma or the ascomycete yeast genus Candida and the basidiomycetous yeast genera Cryptococcus , Rhodosporidium , Rhodotorula , and Trichosporon . Similarly, 83% of the ascomycetous fungi thus far isolated from other aquatic insects, including caddisfly larvae, European nonbiting midge larvae, blackfly larvae, and adult aquatic beetles, are also present in our data set ( 57 – 59 ). As mentioned above, the overlap of fungal community composition within larval stages of various mosquito species and across other aquatic insects may be explained by the high prevalence of these taxa in freshwater habitats ( 28 , 43 – 46 ).…”

Diversity and enzymatic capabilities of fungi associated with the digestive tract of larval stages of a shredder insect in Cerrado and Amazon Forest, Brazil

“…The present results indicated common taxa in both biomes, as is the case of the genus Penicillium, which was the most frequent in this research (40%) and occurred both in the Cerrado and in the Amazon Forest. The genus Penicillium was also found in the DT of larvae of Phylloicus in the same sites of Cerrado and Amazon Forest biomes (Santos et al, 2018) as also in larvae of Triplectides, Phylloicus and Stenochironomus aquatic insects in streams sampled in another site of the Amazon Forest in the State of Amazonas, Brazil, together with Aspergillus and Trichoderma (Belmont-Montefusco et al, 2020a;Belmont-Montefusco et al, 2020b). In addition, the species Paraphaeosphaeria arecacearum, found in the DT of Triplectides in Cerrado, was also isolated in the DT of Phylloicus in the same Cerrado sites by Santos et al (2018).…”

“…Fungi have been often found in the DT of several insects that feed on wood or detritus and, possibly, play a role in the digestion of such plant material (Engel and Moran, 2013;León et al, 2016;Santos et al, 2018;Belmont-Montefusco et al, 2020a, Belmont-Montefusco et al, 2020b. Shredder insects feed on senescent plant material in low-order streams (Graça et al, 2001;Jabiol and Chauvet, 2012) where they contribute to the breakdown of organic matter in aquatic ecosystems together with fungal groups such as Ascomycetes and Hyphomycetes (Graça et al, 2016).…”

Diversity, antibacterial activity and chemical analyses of gut-associated fungi isolated from the Crocothemis servilia

“…Moreover, Penicillium, Aspergillus, and Cladosporium have been associated with other insects' guts, such as termites, honeybees, beetles, and palm weevils (Moubasher et al, 2017;Xu et al, 2020). Trichoderma, Cladosporium, Penicillium, and Talaromyces were also found in the guts of aquatic insect larvae, which have cellulolytic potential (Belmont-Montefusco et al, 2020). Besides, C. lunata and A. alternata isolated from the gut have been reported as plant pathogens (Fahim Abbas et al, 2021).…”