ชีวผลิตภัณฑ์ย่อยสลายสารเคมีกำจัดศัตรูพืชในกลุ่มไพรีทรอยด์ ออร์กาโนฟอสเฟต และคาร์บาเมต

Abstract

Development of bioproduct for degradation pesticide residues in agricultural soil, with beneficial bacteria that are effective in degrading 3 groups of pesticides, i.e. strain SP-TU-C (pyrethroid group degrading), SP-TU-15-2 (organophosphate group) and SP-TU 2-12Y (carbamate group), was conducted. The beneficial bacteria were encapsulated by the spherification method, and later used as a leavening agent for increasing their amount. To increase the number of the beneficial bacteria, three formulas of the media, i.e. (1) TU-F1 (10 g of yeast, 1 L of water), (2) TU-F2 (5 g of yeast, 2.5 g of rice bran, 1 L of water), and (3) TU-F3 (1 g of yeast, 1 g of rice bran, 1 g of ground soybean, 1 L of water) were developed and compared with the standard medium (nutrient glucose broth, NGB). The averaged population of beneficial bacteria strain SP-TU-C, SP-TU-15-2, and SP-TU 2-12Y were 1.59 x 10²³, 3.50 x 10²³, and 2.1 x 10²³ CFU/mL, respectively. The TU-F1 formula was used to study the optimum duration of bacterial culturing. The experimental design was completely randomized design (CRD) with 3 replications, where 10 g of bacterial encapsulate were added to 1 L of TU-F1 formula. The results revealed that the bacteria were grown well, where the lag and log phases were within 3 hours, and entered to stationary phase from 3 to 48 hours after cultured. The shelf life of bioproducts recorded after storage at 5±2 °C for 3 months was revealed that the population of beneficial bacteria of SP-TU-C, SP-TU-15-2 and SP-TU 2-12Y were still stable as 1.0 x 10²³, 3.0 x 10²³ and 9.6 x 10²² CFU/mL, respectively. Longer shelf life should be further confirmed the effectiveness of the developed bioproducts, and the degradation efficiency under field conditions.