Bacillus thuringiensis (Bt) (Bacillales:Bacillaceae) is a gram-positive bacterium that produces spores, several virulence factors and insecticidal toxins, making this microorganism the most used biopesticide worldwide. The use of inert supports such as polyurethane foam (PUF) in solid cultures has been a great alternative to produce various metabolites, including those produced by Bt. In this study we compared the yields, productivity and quality of the spores by two wild strains of Bt, (Y15 and EA3), grown in media with high substrate concentration in both culture systems: liquid and solid (PUF as solid inert support). Both strains showed 2.5- to 30-fold increases in spore production and productivity in solid culture, which showed an even greater increase when considering the spores retained in the PUF observed by scanning electron microscopy. Moreover, spore produced in solid culture showed up to sevenfold higher survival after a heat-shock treatment, relative to spores from liquid culture. The infectivity against larvae of Galleria mellonella (Lepidoptera:Pyralidae) improved also in spores from solid cultures. This comparison showed that the culture of Bt on solid support has clear advantages over liquid culture in terms of the production and quality of spores, and that those advantages can be attributed only to the culture system, as the same media composition was used in both systems.

苏云金芽孢杆菌(Bt) (Bacillales:Bacillaceae) 是一种革兰氏阳性细菌，可产生孢子、几种毒力因子和杀虫毒素，使这种微生物成为世界上使用最多的生物农药。在固体培养中使用惰性载体，例如聚氨酯泡沫 (PUF)，是生产各种代谢物（包括 Bt 产生的代谢物）的绝佳替代方案。在这项研究中，我们比较了两种 Bt 野生菌株（Y15 和 EA3）的孢子产量、生产力和质量，它们在两种培养系统中生长在具有高底物浓度的培养基中：液体和固体（PUF 作为固体惰性载体）。两种菌株在固体培养中的孢子产量和生产力都增加了 2.5 到 30 倍，考虑到通过扫描电子显微镜观察到的 PUF 中保留的孢子，这显示出更大的增加。而且，与液体培养的孢子相比，固体培养中产生的孢子在热休克处理后的存活率高出七倍。对幼虫的传染性Galleria mellonella（鳞翅目：Pyralidae）也在来自固体培养物的孢子中得到改善。该比较表明，在孢子的产生和质量方面，Bt 在固体支持物上的培养比液体培养具有明显的优势，并且这些优势只能归因于培养系统，因为在两个系统中使用相同的培养基组成.