pengembangbiakan bacillus thuringiensis h-14 galur lokal pada berbagai macam ph media air kelapa dan toksisitasnya terhadap jentik nyamuk vektor aedes aegypti dan anopheles aconitus

The culture of bioinsecticide containing active Bacillus thuringiensis H-14 local strain on various kinds on coconut water pH and its toxicity against Aedes aegypti and Anopheles aconitus were carried out in the laboratory on Institute of Vector and Reservoir Control Research and Development Salatiga. The objectives of this study were : To determine the optimum pH from various kinds of coconut water pH forculturing of B. thuringiensis H-14 local strain. This study was using 20 coconuts with 6-8 months age coconut on average weight around 1 kg that contained water approximately 400-500 ml/coconut were taken from Kunir Rejo village, Butuh regency, Purworejo district. Fifteen out of 20 coconuts were used to culture cells and spores of B. thuringiensis H-14 local strain and 5 coconuts were used to analyze the contain of coconut water in the Institute of Health Laboratory Semarang. The results showed, that B. thuringiensis H-14 local strain can culture at ranges from pH 7 to pH 8.5 with the pH7 as the optimum pH. Total Viable Cell (TVC) and a Total Viable Spore Count (TVSC) were 3,5 x 10 degree 10 cells /ml and 3, 3 x 10 degree 10 spores/ml respectively. The Lethal Concentration (LC50) = 10.56 ppm and LC95 = 22. 13 ppm against Ae. agypti larvae and LC50 = 5 ppm and LC95 = 11 ppm against An.aconitus larvae. The result showed the analyze test contain of coconut water were 1.92 % carbohydrate, 0.01 % fat, 0.06 % protein and reduced glucose 1.87 %. Coconut water can be used asan alternative local media to culture B. thuringiensis H-14 local strain.

Key words : B. thuringiensis H-14, pH, coconut water media.