Kajian peningkatan skala fermentor produksi bioinsektisida dari Bacillus thuringiensis aizawai menggunakan substrat limbah cair tahu dan air kelapa

Abstract

Bacillus thuringiensis aizawai is one type of bacteria which often used in the production of microbial bioinsecticide because this patties very effective in controlling larvae of Lepidoptera and Diptera, especially the leaf caterpillar pests of cabbage and other vegetables. The use of biopesticides in Indonesia is still rarely because bioinsecticide marketed in Indonesia is still an import product so that price is relatively expensive. This problem can be overcome with producing bioinsecticide contain active Bacillus thuringiensis aizawai using local raw materials such as liquid waste industrial tofu and coconut water. The objectives of this research was to study the scale up based on the optimum conditions for growth of Bacillus thuringiensis subsp. aizawai in pilot and industrial scale in the production of bioinsecticide microbial use of liquid waste of industrial tofu and coconut water. Carbon-nitrogen ratio in this research is (7:1), with 80 : 20 composition of liquid waste of industrial tofu and coconut water, the starter added 10% (v/v), cultivation time during 72 hours and using fermentors 3 and 40 liters. The highest toxicity of the product can be obtained through bioassay test to larvae Croccidolomia pavonana and the highest toxicity levels is at 48 hours fermentation with LC50 value of 0.01 mg/L. The result showed that by 0.01 mg/L bioinsecticide microbial could kill 50% of the target insect. Range of pH value from 5.25.-7.23, and the highest total plate count (TPC) is 1.44 x 107 CFU/ml in the fermentor with a capacity of 40 litres. The highest viable spore count (VSC) is 8.03 x 105 spores/ml in fermentor with a capacity of 40 litres with cultivation 72 hours. The calculation of the scale up on industrial scale fermentor 10,000 L showed that the needs of Pg/V are 0.0256 HP/m3 per second, a rate of aeration: 0.27 VVM and agitation speed: 0.47 rps. Based on the similarity of geometry fermentor 10,000 litres, fermentor has tank diameter: 2.09 m and impeller diameter: 0.85 m with a working volume of 7,000 litres.