Producción de Bacillus thuringiensis H-14 var. Israelensis utilizando espárrago (Asparagus officinalis) y su uso potencial para el control de la Malaria en la Libertad- Perú

Abstract

Objective: To standardize a culture medium using asparagus infusion (Asparagus officinalis) for the massive production of Bacillus thurigiensis (Bti) H-14 var. israelensis and to determine Bti bio-larvicide effect upon Anopheles sp. in natural breeding sites in Laredo district from January to December, 2000. Materials and methods: Three media based on white asparagus infusion were tested: M 1 : 100-mL infusion, pH: 9; M 2 : 50-mL infusion plus 50-mL buffer phosphate, pH: 7, and M 3 : 25-mL infusion plus 75-mL distilled water, pH: 9. The standard TPH medium was used as a control. Bti production in the different culture media was assessed in order to determine the bio-larvicide effectiveness using LC 50 and LC 90 . The optimum culture medium (lower values for LC 50 and LC 90 ) served for Bti production, and it was evaluated in laboratory and natural breeding sites. Effectiveness was determined measuring larval density prior and after Bti application. Results: The optimum medium for Bti production was M 1 . It showed high effectiveness, with 100% mortality under laboratory conditions, and 71-97% mortality in the field after 24 hours of exposition with three weekly applications. Conclusions: M 1 is the optimum medium for culturing Bti, with high effectiveness for controlling Anopheles larvae both under laboratory and field conditions.