Joseph Jewel Ann, Akkermans Simen, Van Impe Jan F M
BioTeC+, Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, 9000 Ghent, Belgium.
Foods. 2022 May 16;11(10):1438. doi: 10.3390/foods11101438.
The sweet protein thaumatin is emerging as a promising sugar replacer in the market today, especially in the food and beverage sector. Rising demand for its production necessitates the large-scale extraction of this protein from its natural plant source, which can be limited in terms of raw material availability and production costs. Using a recombinant production technique via a yeast platform, specifically, , is more promising to achieve the product economically while maintaining batch-to-batch consistency. However, the bioproduction of recombinant proteins requires the identification of optimal process variables, constituting the maximal yield of the product of interest. These variables have a direct effect on the growth of the host organism and the secretion levels of the recombinant protein. In this study, two important environmental factors, pH, and temperature were assessed by cultivating in shake flasks to understand their influence on growth and the production levels of thaumatin II protein. The results from the pH study indicate that attained a higher viable cell density and secretion of protein at pH 6.0 compared to 5.0 when grown at 30 °C. Furthermore, within the three levels of temperatures investigated when grown at pH 6.0, the protein levels were the highest at 30 °C compared to 20 and 25 °C, whereas 25 °C exhibited the highest viable cell density. Interestingly, the trend observed from the qualitative effects of temperature and pH occurred in all the media that was investigated. These results broaden our understanding of how pH and temperature adjustment during cultivation aid in enhancing the production yields of thaumatin II prior to optimising the fed batch bioreactor operation.
甜味蛋白奇异果甜蛋白如今在市场上正成为一种很有前景的糖替代品，尤其是在食品和饮料行业。对其生产的需求不断增加，这就需要从其天然植物来源大规模提取这种蛋白，而天然植物来源在原材料供应和生产成本方面可能会受到限制。通过酵母平台使用重组生产技术，具体来说，在经济上实现产品生产并保持批次间的一致性更具前景。然而，重组蛋白的生物生产需要确定最佳工艺变量，以实现目标产物的最大产量。这些变量直接影响宿主生物体的生长和重组蛋白的分泌水平。在本研究中，通过在摇瓶中培养来评估两个重要的环境因素，即pH值和温度，以了解它们对奇异果甜蛋白II生长和生产水平的影响。pH研究结果表明，在30℃培养时，与pH 5.0相比，在pH 6.0时获得了更高的活细胞密度和蛋白分泌量。此外，在pH 6.0培养时所研究的三个温度水平下，与20℃和25℃相比，30℃时的蛋白水平最高，而25℃时活细胞密度最高。有趣的是，在所研究的所有培养基中都观察到了温度和pH定性影响的这种趋势。这些结果拓宽了我们对于在优化补料分批生物反应器操作之前，奇异果甜蛋白培养过程中pH和温度调节如何有助于提高其产量的理解。
