Research Initiation: High Density Cultivation of Bacillus Thuringiensis Cells

本研究将集中于实现…的高生产率。通过搅拌式生物反应器控制投料间歇式操作，从苏云金芽孢杆菌细胞中分离-内毒素蛋白。该策略包括在营养阶段将细胞培养到高浓度，在此期间发酵参数将被控制，以尽量减少不良有毒产物的形成。连续培养技术将确定细胞向高密度生长所需的最低营养需求。补料分批培养将被微调，以便高密度的培养基成分对随后的孢子形成和内毒素形成是最佳的。生物杀虫剂越来越被认为比化学杀虫剂更有利，化学杀虫剂通常是能源密集型的，半衰期长，并对许多无害的生命形式产生不利影响。内毒素是一种商业生产的杀虫剂，目前正在广泛研究其效力的重大改进。此外，孢子形成杆菌通常用于生产许多重要的工业产品；因此，涉及高密度栽培的基础研究可以提高几个过程的生产率。

This study will concentrate upon achieving high productivity of .-endotoxin protein by Bacillus Thuringiensis cells by controlled fed- batch operation of stirred bioreactors. The strategy involves growing the cells to high concentrations in vegetative phase during which the fermentation parameters will be controlled to minimize formation of undesirable toxic products. Minimal requirements of nutrients for cell growth to high densities will be established by continuous cultivation techniques. The fed-batch cultivation will be fine tuned so that medium composition at high densities is optimum for subsequent sporulation and endotoxin formation. Biological insecticides are increasingly being viewed as more advantageous than chemical pesticides which are generally energy intensive, have long half lives, and adversely affect many harmless forms of life. .-endotoxin is a commercially produced insecticide that is being studied extensively with major improvements in its potency. In addition, spore-forming bacilli are commonly used to produce many industrially important products; therefore, fundamental studies involving high density cultivation can improve productivity of several processes.