Synergisitic effect of chitinases and Bacillus thuringiensis israelensis spore-toxin complex against Aedes aegypti larvae Academic Article uri icon


  • AbstractSix subspecies ofBacillus thuringiensisBerliner (Bt) were grown in minimal medium with chitin as the sole carbon source for 6 days to obtainBtcell-free fermented broths, which were then evaluated for chitinolytic activity and tested against third-instarAedes aegypti(L.) (Diptera: Culicidae) larvae.Bt pakistanishowed the highest chitinolytic activity (approximately >2700 mU/mL),Bt kurstakishowed the lowest activity (approximately <2000 mU/mL), andBt thompsoni,Bt aizawai,Bt israelensis, andBt alestishowed intermediate activities (approximately 21002400 mU/mL).Bt aizawaiandBt thompsonibroths showed the highest toxicity (LC50) against third-instarA. aegyptilarvae (approximately <290 mU/mL).Bt kurstakibroth showed the lowest toxicity (approximately 420 mU/mL), whileBt pakistani,Bt israelensis, andBt alestibroths showed intermediate toxicities (approximately 360460 mU/mL). A purified and biochemically characterizedBt aizawaichitinase and commercial chitinases (fromSerratia marcescensBizio andStreptomyces griseusWaksman and Henrici) were evaluated and compared for synergistic effects onBt israelensisspore-toxin complex against third-instarA. aegyptilarvae. The synergism factor value ofStreptomyces griseusandBt aizawaichitinases were >2 and approximately 1.4; synergism was not evident for theSerratia marcescenschitinase (synergism factor value approximately 0.9).

published proceedings


author list (cited authors)

  • Ramirez-Suero, M., Valerio-Alfaro, G., Bernal, J. S., & Ramirez-Lepe, M.

citation count

  • 9

complete list of authors

  • Ramírez-Suero, Montserrat||Valerio-Alfaro, Gerardo||Bernal, Julio S||Ramírez-Lepe, Mario

publication date

  • April 2011