K. Arevalonino et Lj. Galanwong, USE OF A SIMPLE METHOD FOR DETECTION OF B ETA-EXOTOXIN IN STRAINS OF BACILLUS-THURINGIENSIS, The Southwestern entomologist, 19(4), 1994, pp. 385-391
A simple chemical analysis method was used for beta-exotoxin detection
in subspecies of Bacillus thuringiensis. Native strains and Internati
onal Collection strains belonging to the thuringiensis variety (HD-41
and HD-59), reported as producers of beta-exotoxin, were tested. Both
strains showed typical absortion UV spectra for the toxin used as refe
rence stock in this work. HD-41 produced 6.8 mg/l of culture medium, w
hile HD-59 produced 27.2 mg/l. These results were confirmed with bioas
says with third instar Musca domestica larvae; LD50's of 240 and 98.28
mul/g were obtained for HD-59 and the reference stock, respectively.
None of the native strains showed positive results for the toxin with
this method, which was confirmed by mortalities lower than 10% obtaine
d in bioassays.