Khatun Most Sheauly, Hassanpour Morteza, Harrison Mark D, Speight Robert E, O'Hara Ian M, Zhang Zhanying
Centre for Agriculture and the Bioeconomy, Faculty of Science, Queensland University of Technology, Brisbane, QLD, 4000, Australia.
School of Mechanical, Medical and Process Engineering, Faculty of Engineering, Queensland University of Technology, Brisbane, QLD, 4000, Australia.
Bioresour Bioprocess. 2021 Jun 11;8(1):48. doi: 10.1186/s40643-021-00399-x.
Fructooligosaccharides (FOS) are a type of important prebiotics and produced by transfructosylating enzymes. In this study, sugarcane molasses was used as the substrate for production of transfructosylating enzymes by Aureobasidium pullulans FRR 5284. NaNO was a superior nitrogen source to yeast extract for production of transfructosylating enzymes by A. pullulans FRR 5284 and decreasing the ratio of NaNO to yeast extract nitrogen from 1:0 to 1:1 resulted in the reduction of the total transfructosylating activity from 109.8 U/mL to 82.5 U/mL. The addition of only 4.4 g/L NaNO into molasses-based medium containing 100 g/L mono- and di-saccharides resulted in total transfructosylating activity of 123.8 U/mL. Scale-up of the A. pullulans FRR 5284 transfructosylating enzyme production process from shake flasks to 1 L bioreactors improved the enzyme activity and productivity to 171.7 U/mL and 3.58 U/mL/h, 39% and 108% higher than those achieved from shake flasks, respectively. Sucrose (500 g/L) was used as a substrate for extracellular, intracellular, and total A. pullulans FRR 5284 transfructosylating enzymes, with a maximum yield of 61%. Intracellular, extracellular, and total A. pullulans FRR 5284 transfructosylating enzymes from different production systems resulted in different FOS profiles, indicating that FOS profiles can be controlled by adjusting intracellular and extracellular enzyme ratios and, hence prebiotic activity.
低聚果糖（FOS）是一类重要的益生元，由转果糖基酶产生。在本研究中，甘蔗 molasses 被用作 Aureobasidium pullulans FRR 5284 生产转果糖基酶的底物。对于 Aureobasidium pullulans FRR 5284 生产转果糖基酶而言，NaNO 是比酵母提取物更优的氮源，将 NaNO 与酵母提取物氮的比例从 1:0 降至 1:1 导致总转果糖基酶活性从 109.8 U/mL 降至 82.5 U/mL。在含有 100 g/L 单糖和二糖的 molasses 基培养基中仅添加 4.4 g/L NaNO，可使总转果糖基酶活性达到 123.8 U/mL。将 Aureobasidium pullulans FRR 5284 转果糖基酶生产过程从摇瓶放大至 1 L 生物反应器，可将酶活性和生产力分别提高至 171.7 U/mL 和 3.58 U/mL/h，分别比摇瓶培养提高了 39% 和 108%。蔗糖（500 g/L）用作 Aureobasidium pullulans FRR 5284 细胞外、细胞内和总转果糖基酶的底物，最大产率为 61%。来自不同生产系统的 Aureobasidium pullulans FRR 5284 细胞内、细胞外和总转果糖基酶产生不同的 FOS 谱，表明可通过调节细胞内和细胞外酶的比例来控制 FOS 谱，进而控制益生元活性。
