Appl Environ Microbiol. 1997 Sep;63(9):3561-8. doi: 10.1128/aem.63.9.3561-3568.1997.
The insecticidal toxins produced by Bacillus thuringiensis subspp. kurstaki and tenebrionis were resistant when bound on clays, but not when free, to utilization by pure and mixed cultures of microbes as sources of carbon and carbon plus nitrogen, and their availability as a nitrogen source was reduced. The bound toxins retained insecticidal activity both before and after exposure to microbes or pronase. The insecticidal activity of the toxins persisted for 40 days (the longest time evaluated) in nonsterile soil continuously maintained at the -33-kPa water tension and room temperature, alternately air dried and rewetted to the -33-kPa water tension, or alternately frozen and thawed, although alternate drying and wetting reduced the activity.
苏云金芽孢杆菌亚种 kurstaki 和 tenebrionis 产生的杀虫毒素与粘土结合时具有抗药性，但在作为微生物纯培养和混合培养的碳源和碳加氮源时没有抗药性，并且其作为氮源的可用性降低。结合毒素在暴露于微生物或蛋白酶之前和之后都保持杀虫活性。在非无菌土壤中，杀虫毒素的杀虫活性持续了 40 天（最长时间评估），土壤温度保持在-33kPa 水张力，室温，交替风干和再润湿至-33kPa 水张力，或交替冷冻和解冻，尽管交替干燥和润湿会降低其活性。
