Bauer Andreas, Minceva Mirjana
Biothermodynamics, TUM School of Life Sciences, Technical University of Munich, Maximus-von-Imhof-Forum 2, 85354, Freising, Germany.
Bioresour Bioprocess. 2021 Nov 8;8(1):111. doi: 10.1186/s40643-021-00463-6.
The biotechnological production of the carotenoid astaxanthin is done with the microalgae Haematococcus pluvialis (H. pluvialis). Under nutrient deficiency and light stress, H. pluvialis accumulates astaxanthin intracellularly and forms a resistant cyst cell wall that impedes direct astaxanthin extraction. Therefore, a complex downstream process is required, including centrifugation, mechanical cell wall disruption, drying, and supercritical extraction of astaxanthin with CO. In this work, an alternative downstream process based on the direct extraction of astaxanthin from the algal broth into ethyl acetate using a centrifugal partition extractor (CPE) was developed. A mechanical cell wall disruption or germination of the cysts was carried out to make astaxanthin accessible to the solvent. Zoospores containing astaxanthin are released when growth conditions are applied to cyst cells, from which astaxanthin can directly be extracted into ethyl acetate. Energy-intensive unit operations such as spray-drying and extraction with supercritical CO can be replaced by directly extracting astaxanthin into ethyl acetate. Extraction yields of 85% were reached, and 3.5 g of oleoresin could be extracted from 7.85 g homogenised H. pluvialis biomass using a CPE unit with 244 mL column volume. A techno-economic analysis was done for a hypothetical H. pluvialis production facility with an annual biomass output of 8910 kg. Four downstream scenarios were examined, comparing the novel process of astaxanthin extraction from homogenised cyst cells and germinated zoospores via CPE extraction with the conventional industrial process using in-house or supercritical CO extraction via an external service provider. After 10 years of operation, the highest net present value (NPV) was determined for the CPE extraction from germinated zoospores.
类胡萝卜素虾青素的生物技术生产是通过雨生红球藻（H. pluvialis）来完成的。在营养缺乏和光照胁迫条件下，雨生红球藻在细胞内积累虾青素，并形成一层抗性囊壁，这阻碍了虾青素的直接提取。因此，需要一个复杂的下游工艺，包括离心、机械破壁、干燥以及用二氧化碳对虾青素进行超临界萃取。在这项研究中，开发了一种基于使用离心分配萃取器（CPE）将虾青素从藻液直接萃取到乙酸乙酯中的替代下游工艺。通过机械破壁或使囊肿萌发，让虾青素能够接触到溶剂。当对囊肿细胞施加生长条件时，会释放出含有虾青素的游动孢子，虾青素可直接从游动孢子中萃取到乙酸乙酯中。诸如喷雾干燥和用超临界二氧化碳萃取等能源密集型单元操作可以被将虾青素直接萃取到乙酸乙酯的操作所取代。萃取产率达到了85%，使用柱体积为244毫升的CPE装置，从7.85克均质化的雨生红球藻生物质中可以萃取出3.5克含油树脂。对一个假设的年产量为8910千克雨生红球藻的生产设施进行了技术经济分析。研究了四种下游工艺方案，将通过CPE萃取从均质化囊肿细胞和萌发的游动孢子中提取虾青素的新工艺与使用内部或通过外部服务提供商进行超临界二氧化碳萃取的传统工业工艺进行了比较。运行10年后，从萌发的游动孢子中进行CPE萃取的净现值最高。
