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

PLoS One. 2017 Mar 30;12(3):e0174754. doi: 10.1371/journal.pone.0174754. eCollection 2017.

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.

MeSH terms

  • Animals
  • Bacteria / drug effects
  • Benzamides / pharmacology
  • Biotechnology
  • Drug Combinations
  • Gas Chromatography-Mass Spectrometry
  • Gastrointestinal Microbiome / physiology*
  • Insecticides / pharmacology*
  • Macrolides / pharmacology
  • Nitriles / pharmacology
  • Pyrethrins / pharmacology
  • Spodoptera / microbiology
  • Tandem Mass Spectrometry

Substances

  • Benzamides
  • Drug Combinations
  • Insecticides
  • Macrolides
  • Nitriles
  • Pyrethrins
  • fluphenacur
  • decamethrin
  • cyhalothrin
  • spinosad

Grants and funding

Fundação de Amparo à Pesquisa do Estado de São Paulo provided a fellowship to LGA (FAPESP Process 2010/13714-3) and a research grant to the senior author (FAPESP Process 2011/50877-0). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.