Bacillus thuringiensis (Bt) toxin released from root exudates and biomass of Bt corn has no apparent effect on earthworms, nematodes, protozoa, bacteria, and fungi in soil

D. Saxena, G. Stotzky

Research output: Contribution to journalArticle

Abstract

There were no significant differences in the percent mortality and weight of earthworms (Lumbricus terrestris) after 40 days in soil planted with Bt (NK4640Bt) or non-Bt corn or after 45 days in soil amended with biomass of Bt or non-Bt corn. The toxin was present in the guts and casts of earthworms in soil planted with Bt corn or amended with biomass of Bt corn, but it was cleared within 2-3 days from the guts after placing in fresh soil. There were no significant differences in the colony-forming units of culturable bacteria (including actinomycetes) and fungi and in the numbers of protozoa and nematodes between rhizosphere soil of Bt and non-Bt corn or between soil amended with biomass of Bt and non-Bt corn. The Cry1Ab protein in root exudates and biomass of Bt corn appears not to be toxic to earthworms, nematodes, protozoa, bacteria, and fungi. The presence of the toxin in the guts and casts of earthworms confirmed that the toxin released in root exudates and from transgenic biomass was bound on surface-active particles in soil, which protected the toxin from biodegradation, as has been observed in this laboratory with purified toxin.

Original languageEnglish (US)
Pages (from-to)1225-1230
Number of pages6
JournalSoil Biology and Biochemistry
Volume33
Issue number9
DOIs
StatePublished - Jul 30 2001

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Keywords

  • Bacillus thuringiensis
  • Biomass of Bt corn
  • Bt corn
  • Cry1Ab toxin
  • Earthworms
  • Microorganisms
  • Nematodes
  • Root exudates

ASJC Scopus subject areas

  • Microbiology
  • Soil Science

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