杀线虫苏云金芽胞杆菌NBIN-863高含量悬浮剂的研制

目前我国微生物农药原药生产技术已达到甚至超过发达国家水平，但制剂技术却存在较大差距，主要体现在剂型结构不合理、制剂质量差、农药助剂种类及品种少、剂型加工工艺总体水平还比较落后等方面。苏云金芽胞杆菌(Bt)等功能微生物产品的市场容量及应用效果与剂型是密切相关的。为了明确新型生物杀线剂NBIN-863的最佳施用剂型，特开展此试验。通过对防腐剂、分散剂、悬浮剂等不同助剂的选择，研制了一种高含量Bt悬浮剂(5.2×10⁹～7.9×10⁹ CFU/mL)。配方优化试验表明，在Bt发酵液中加入0.4%防腐剂山梨酸钾、1.0%分散剂硅酸镁铝、4.0%悬浮剂木质素磺酸钙，用盐酸调节p H至4.5,54℃热储前芽胞数最高为7.9×10⁹ CFU/mL，对秀丽隐杆线虫活性最高，LC₅₀为2.83 mg/L，对黄瓜根结线虫田间防效达68.64%。综合各指标，尤其是对秀丽隐杆线虫的半致死浓度，杀线虫NBIN-863悬浮剂(7.9×10⁹CFU/mL)效果最好，不仅流动性好，而且耐贮藏，是防治作物根结线...

Development of High Content Suspension of Nematocidal Bacillus thuringiensis NBIN-863

At present, the production technology of microbial pesticide technical materials in China has reached or even exceeded the level of developed countries, but there is a large gap in preparation technology, which is mainly reflected in the unreasonable dosage form structure, poor preparation quality, only a few pesticide additives, and the overall low level of dosage form processing technique. The market demand and application benefit of functional microbial products such as Bacillus thuringiensis (Bt) are closely related to the dosage form. This test was initiated to determine the best dosage form of the new biological nematicide NBIN-863. A high content Bt suspension (5.2―7.9 billion CFU/mL) was developed by selecting different additives, including preservative, dispersant and suspending agent. The dosage form was optimized by adding 0.4% preservative potassium sorbate, 1.0% dispersant magnesium aluminum silicate, and 4.0% suspending agent calcium lignosulfonate to the Bt fermentation broth, and by adjusting the pH value to 4.5 using hydrochloric acid, which produced the maximum number of spores 7.9×10⁹ CFU/mL before the thermal storage at 54 ℃. The dosage form showed the highest activity against Caenorhabditis elegans, with a LC₅₀ value of 2.83 mg/L, and field control efficiency on cucumber root knot nematode of 68.64%. Based on all the indexes, especially the half lethal concentration to Caenorhabditis elegans, the nematocidal NBIN-863 suspension (7.9 billion CFU/mL), with good fluidity and long shelf life, is of high potential for controlling crop root knot nematode disease.