The gut microbiota of insecticide-resistant insects houses insecticide-degrading bacteria: A potential source for biotechnological exploitation

Abstract

The exploration of new niches for microorganisms capable of degrading recalcitrant molecules is still required. We hypothesized the gut microbiota associated with insect-resistant lines carry pesticide degrading bacteria, and predicted they carry bacteria selected to degrade pesticides they were resistant to. We isolated and accessed the pesticide-degrading capacity of gut bacteria from the gut of fifth instars of Spodoptera frugiperda strains resistant to lambda-cyhalothrin, deltamethrin, chlorpyrifos ethyl, spinosad and lufenuron, using insecticide-selective media. Sixteen isolates belonging to 10 phylotypes were obtained, from which four were also associated with the susceptible strain. However, growth of gut bacteria associated with larvae from the susceptible strain was not obtained in any of the insecticide-based selective media tested. Growth of isolates was affected by the concentration of insecticides in the media, and all grew well up to 40 μg/ml. The insecticide-degrading capacity of selected isolates was assessed by GC or LC-MS/MS analyses. In conclusion, resistant strains of S. frugiperda are an excellent reservoir of insecticide-degrading bacteria with bioremediation potential. Moreover, gut-associated bacteria are subjected to the selection pressure imposed by insecticides on their hosts and may influence the metabolization of pesticides in insects.

Diversity of fall armyworm, Spodoptera frugiperda and their gut bacterial community in Kenya

“…Only three samples, two adult males from Kitale (Kitale-m2 and Kitale-m3) and one larvae from Ngeria (Ngeria-l2) were dominated by Firmicutes. Four genera of bacteria, Pseudomonas, Delftia, Enterococcus and Serratia that were recorded in this study have 15 previously been isolated from S. frugiperda (De Almeida et al 2017; Acevedo et al 2017). Surprisingly, Staphylococcus, Microbacterium, Arthrobacter and Leclercia that were previously isolated from S. frugiperda in Brazil (De Almeida et al 2017) were not found in any of the samples we profiled in Kenya.…”

“…Symbiotic bacteria play a key role in the biology of insects. We characterized the gut bacterial communities in S. frugiperda larvae and adult samples collected from several locations in Kenya, finding some important differences and similarities across samples and in relation to other studies on this species (Acevedo et al 2017; De Almeida et al 2017). Understanding the gut microbial symbionts of this pest species may facilitate the development of novel, cost-effective control strategies.…”

“…In Spodoptera exigua , the dominant bacterial clades are Proteobacteria and Firmicutes, with the predominant genus in larvae being Enterococcus . In S. frugiperda , previous studies have isolated several bacterial strains using culture-dependent methods (De Almeida et al 2017; Acevedo et al 2017). In this study, we used 16S rDNA sequence profiling to characterize the diversity of bacteria associated with populations of S. frugiperda in Kenya and assessed the prevalence of the corn and rice strains in these populations using Mitochondrial COI gene sequences.…”

Annotation of gut bacterial taxonomic and functional diversity in Spodoptera litura and Spilosoma obliqua

“…The symbiotic Burkholderia are able to degrade the insecticide fenitrothion, a prevalent organophosphorus agent in agriculture [40]. Isolated the pesticide-degrading bacteria and assessed their capacity using GC or LC-MS/MS analyses from fifth instars of Spodoptera frugiperda strains resistant to lambda-cyhalothrin, deltamethrin, chlorpyrifos ethyl, spinosad, and lufenuron [41]. Substantiating the earlier literature present study can be hypothesized or assumed the role of gut microbiome in successful establishment of both defoliatorsas phytophagous on different field crops (nutrition) and attenuation of pesticides (detoxification).…”

Microbiota of Telenomus tridentatus (Platygastroidea: Scelionidae): An unwanted parasitoid

“…Bacterial symbionts inhabiting insects can significantly influence the biology of their host depending on whether they are needed by the host to survive or provide nonessential benefits (Paniagua Voirol, Frago, Kaltenpoth, Hilker, & Fatouros, ). Most of them play an important role because they contribute to various aspects of host physiology (such as nutrition), tolerance to environmental perturbations (Engel & Moran, ), resistance against natural enemies like parasites (Oliver, Russell, Moran, & Hunter, ), resistance against insecticides (Almeida, Moraes, Trigo, Omoto, & Consoli, ) and contribute to their longevity (Behar, Yuval, & Jurkevitch, ). Nevertheless, their study was somehow difficult years ago because the estimation of microbiota was mainly based on culturable bacteria.…”