EMBRAPA Genetic Resources and Biotechnology, Brasilia, DF, Brazil.
Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand.
J Appl Microbiol. 2019 Jan;126(1):155-164. doi: 10.1111/jam.14137. Epub 2018 Nov 20.
To describe a new approach in which production of conidia of an entomopathogenic fungus takes place on the surface of an unstirred shallow liquid culture kept in nonabsorbent wells distributed in plastic sheets resembling a honeycomb.
First, liquid incubation time and medium composition for production of Beauveria bassiana aerial conidia were optimized. Wells inoculated with Sabouraud dextrose yeast extract produced 2·2 × 10 conidia per cm of liquid surface following 5 days of incubation. Finally, tests were carried out in a prototype comprised of stacked plastic sheets in a cylindrical container. Conidia production on liquid culture surface varied from 1·2 to 1·6 × 10 conidia per ml of fermented broth. Germination rates and insect activity towards Tenebrio molitor larvae were not negatively affected when compared to conidia produced on solid medium.
The two-stage fermentation process here described, based on a simple nonabsorbent inert support, has potential for the application in the production of aerial conidia of B. bassiana and other fungi.
Aerial conidia are the most extensive propagule type used in commercial mycopesticides, traditionally produced by solid-state fermentation (SSF). The industrial applications and other important benefits of the two-stage fermentation process here described may overcome some hurdles inherent to SSF aiming for the production of aerial conidia. Additionally, production consistency is increased by the use of chemically defined medium, and the better control of the environmental conditions could allow for more reproducible industrial batches.
描述一种新方法，即在不吸收的浅液培养表面上产生一种昆虫病原真菌的分生孢子，该培养保存在类似于蜂窝的塑料薄片中的非吸收性井中。
首先，优化了球孢白僵菌气生分生孢子生产的液体培养时间和培养基组成。在萨布罗葡萄糖酵母提取物中接种的井在 5 天的孵育后产生了 2.2×10 个分生孢子/cm 液体表面。最后，在由圆柱形容器中堆叠的塑料薄片组成的原型中进行了测试。液体培养表面上的分生孢子产量从 1.2 到 1.6×10 个/ml 发酵液变化。与在固体培养基上产生的分生孢子相比，萌发率和对黄粉虫幼虫的昆虫活性没有受到负面影响。
这里描述的基于简单非吸收性惰性支持物的两段发酵工艺具有在生产白僵菌和其他真菌气生分生孢子中的应用潜力。
气生分生孢子是商业真菌杀虫剂中最广泛使用的繁殖体类型，传统上由固态发酵（SSF）生产。这里描述的两段发酵工艺的工业应用和其他重要好处可能克服了 SSF 生产气生分生孢子所固有的一些障碍。此外，使用化学定义的培养基增加了生产的一致性，并且对环境条件的更好控制可以允许更可重复的工业批次。
