Multifunctional Properties of a Bacillus thuringiensis Strain (BST-122): Beyond the Parasporal Crystal

Toxins (Basel). 2022 Nov 7;14(11):768. doi: 10.3390/toxins14110768.

Abstract

Chemical products still represent the most common form of controlling crop pests and diseases. However, their extensive use has led to the selection of resistances. This makes the finding of new solutions paramount to countering the economic losses that pests and diseases represent in modern agriculture. Bacillus thuringiensis (Bt) is one of the most reliable alternatives to chemical-based solutions. In this study, we aimed to further expand the global applicability of Bt strains beyond their spores and crystals. To this end, we selected a new Bt strain (BST-122) with relevant toxicity factors and tested its activity against species belonging to different phyla. The spore and crystal mixture showed toxicity to coleopterans. Additionally, a novel Cry5-like protein proved active against the two-spotted spider mite. In vivo and plant assays revealed significant control of the parasitic nematode, Meloidogyne incognita. Surprisingly, our data indicated that the nematocidal determinants may be secreted. When evaluated against phytopathogenic fungi, the strain seemed to decelerate their growth. Overall, our research has highlighted the potential of Bt strains, expanding their use beyond the confinements of spores and crystals. However, further studies are required to pinpoint the factors responsible for the wide host range properties of the BST-122 strain.

Keywords: Bacillus thuringiensis; Coleoptera; bioassays; mite; multifunctional; phytopathogenic fungi; plant-parasitic nematode; toxicity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacillus thuringiensis Toxins
  • Bacillus thuringiensis* / metabolism
  • Bacterial Proteins / metabolism
  • Endotoxins / metabolism
  • Hemolysin Proteins / metabolism

Substances

  • Bacillus thuringiensis Toxins
  • Hemolysin Proteins
  • Endotoxins
  • Bacterial Proteins

Grants and funding

A. Unzue Doctorados Industriales predoctoral contract was cofounded by Gobierno de Navarra (0011-1408-2017-000027) and Bioinsectis SL. A. B. Fernández contract was cofounded by the Program Torres Quevedo (Ministerio de Ciencia, Innovación y Universidades, Gobierno de España) (PTQ-2018-010091) and Bioinsectis SL.