FIGURE 1.

The CT-A component prepared from B. thuringiensis CT-43-55 in class 2 showed nematicidal activity on the plant-parasitic nematode M. incognita. A, classification of strain CT-43 and its plasmid-deficient mutants according to the production profile of CT-A (blue peak) and thuringiensin (red peak). The plasmid-deficient mutant CT-43-55 in class 2 is preferred for CT-A preparation over strains that produce thuringiensin. B, bioassay of a highly purified CT-A sample extracted from B. thuringiensis CT-43-55 on the J2s of the plant-parasitic root knot nematode M. incognita. The bioassay included three biological repeats, and treatment at each TAA concentration included three technological repeats. After 72 h, total and living J2s were counted and used to calculate the LC₅₀ values by probit analysis (IBM SPSS software). Error bars, S.D. AU, absorbance units.