State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi, 530004, China.
College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi, 530004, China.
Appl Biochem Biotechnol. 2018 Aug;185(4):1088-1099. doi: 10.1007/s12010-018-2706-6. Epub 2018 Feb 13.
The coarse perlite 40-80 mesh was selected as an immobilizing material and put into a packed bed reactor (PBR) to continuously convert maltose to isomalto-oligosaccharides (IMOs). The PBR was prepared by mixing the thermo-inactivated cells (TIC) from Aspergillus niger J2 strain with the coarse perlite, then the mixture was put into an overpressure-resistant column. Compared with diatomite 40-80 mesh and thin perlite 80-120 mesh in PBR, coarse perlite was chosen as the best filtration aid, when the ratio of coarse perlite versus TIC was 1:1. The thermal and pH stability of the free and immobilized TIC and the optimum conditions for the transglycosylation reactions were determined. The results show that approximately 75 and 82% and 87 and 91% of α-glucosidase activity were reserved for free and immobilized TIC at temperatures from 30 to 60 °C and pH from 3.00 to 7.00 for 12 h, respectively. With 30% malt syrup under the conditions of 50 °C and pH 4.00, a mini-scale packed bed reactor (Mi-PBR) and medium-scale packed bed reactor (Me-PBR) could continuously produce IMO over 25 and 34 days with the yield of effective IMO (eIMO) ≥ 35% and total IMO (tIMO) ≥ 50%, respectively. The strategy of mixing the coarse perlite with TIC in PBR is a novel approach to continuously produce IMO and has great application potential in industry.
粗珍珠岩 40-80 目被选为固定化材料，并放入填充床反应器（PBR）中，将麦芽糖连续转化为异麦芽低聚糖（IMO）。PBR 是通过将黑曲霉 J2 菌株的热失活细胞（TIC）与粗珍珠岩混合制备的，然后将混合物放入耐压柱中。与硅藻土 40-80 目和细珍珠岩 80-120 目相比，粗珍珠岩被选为最佳过滤助剂，当粗珍珠岩与 TIC 的比例为 1:1 时。测定了游离和固定化 TIC 的热稳定性和 pH 稳定性以及转糖苷反应的最佳条件。结果表明，游离和固定化 TIC 的α-葡萄糖苷酶活性分别在 30-60°C 和 pH 3.00-7.00 下保持约 75%和 82%和 87%和 91%，12 小时。在 50°C 和 pH 4.00 下，用 30%麦芽糖，小型填充床反应器（Mi-PBR）和中型填充床反应器（Me-PBR）可分别连续生产 25 天和 34 天以上，有效 IMO（eIMO）的产率≥35%和总 IMO（tIMO）≥50%。在 PBR 中用粗珍珠岩与 TIC 混合的策略是连续生产 IMO 的一种新方法，在工业上具有很大的应用潜力。
