Harith Zuharlida Tuan, de Andrade Lima Micael, Charalampopoulos Dimitris, Chatzifragkou Afroditi
Faculty of Agro Based Industry, Universiti Malaysia Kelantan Jeli Campus, Jeli 17600, Kelantan, Malaysia.
Department of Food and Nutritional Sciences, University of Reading, Whiteknights, P.O. Box 226, Reading RG6 6AP, UK.
Microorganisms. 2020 Mar 19;8(3):430. doi: 10.3390/microorganisms8030430.
Currently, astaxanthin demand is fulfilled by chemical synthesis using petroleum-based feedstocks. As such, alternative pathways of natural astaxanthin production attracts much research interest. This study aimed at optimising bioreactor operation parameters for astaxanthin production and evaluating strategies for its subsequent extraction. The effect of pH and agitation was evident, as a significant reduction in both biomass and astaxanthin production was observed when the culture pH was not controlled and a low agitation speed was applied. At controlled pH conditions and a high agitation speed, a significant increase in biomass (16.4 g/L) and astaxanthin production (3.6 mg/L) was obtained. Enzymatic yeast cell lysis using two commercial enzymes (Accellerase 1500 and Glucanex) was optimised using the central composite design of experiment (DoE). Accellerase 1500 led to mild cell disruption and only 9% () astaxanthin extraction. However, Glucanex treatment resulted in complete astaxanthin extractability, compared to standard extraction method (DMSO/acetone). When supercritical CO was employed as an extraction solvent in Accellerase-pre-treated cells, astaxanthin extraction increased 2.5-fold. Overall, the study showed that extraction conditions can be tailored towards targeted pigments present in complex mixtures, such as in microbial cells.
目前，虾青素的需求通过使用石油基原料的化学合成来满足。因此，天然虾青素生产的替代途径引起了众多研究兴趣。本研究旨在优化用于生产虾青素的生物反应器操作参数，并评估其后续提取策略。pH值和搅拌的影响很明显，当培养pH值不受控制且搅拌速度较低时，生物量和虾青素产量均显著降低。在pH值受控和搅拌速度较高的条件下，生物量（16.4 g/L）和虾青素产量（3.6 mg/L）显著增加。使用实验的中心复合设计（DoE）优化了使用两种商业酶（Accellerase 1500和Glucanex）进行的酶促酵母细胞裂解。Accellerase 1500导致细胞轻度破碎，虾青素提取率仅为9%（）。然而，与标准提取方法（二甲基亚砜/丙酮）相比，Glucanex处理可使虾青素完全提取。当超临界CO用作Accellerase预处理细胞的提取溶剂时，虾青素提取量增加了2.5倍。总体而言，该研究表明，提取条件可针对复杂混合物（如微生物细胞）中存在的目标色素进行调整。
