School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2 Xuelin Road, Qixia District, Nanjing, People's Republic of China.
School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2 Xuelin Road, Qixia District, Nanjing, People's Republic of China.
Biotechnol Adv. 2021 May-Jun;48:107725. doi: 10.1016/j.biotechadv.2021.107725. Epub 2021 Mar 13.
As fungus-like protists, thraustochytrids have been increasingly studied for their faster growth rates and high lipid content. In the 1990s, thraustochytrids were used as docosahexaenoic acid (DHA) producers for the first time. Thraustochytrids genera, such as Thraustochytrium, Schizochytrium, and Aurantiochytrium have been developed and patented as industrial strains for DHA production. The high DHA yield is attributed to its unique and efficient polyketide-like synthase (PKS) pathway. Moreover, thraustochytrids possess a completed mevalonate (MVA) pathway, so it can be used as host for terpenoid production. In order to improve strain performance, the metabolic engineering strategies have been applied to promote or disrupt intracellular metabolic pathways, such as genetic engineering and addition of chemical activators. However, it is difficult to realize industrialization only by improving strain performance. Various operation strategies were developed to enlarge the production quantities from the laboratory-scale, including two-stage cultivation strategies, scale-up technologies and bioreactor design. Moreover, an economical and effective downstream process is also an important consideration for the industrial application of thraustochytrids. Downstream costs accounts for 20-60% of the overall process costs, which represents an attractive target for increasing the cost-competitiveness of thraustochytrids, including how to improve the efficiency of lipid extraction and the further application of biomass residues. This review aims to overview the whole lipid biotechnology of thraustochytrids to provide the background information for researchers.
作为真菌样原生生物，旋毛藻已因其更快的生长速度和高脂质含量而受到越来越多的研究。20 世纪 90 年代，旋毛藻首次被用作二十二碳六烯酸（DHA）的生产者。旋毛藻属（Thraustochytrium）、裂殖壶菌属（Schizochytrium）和金黄囊藻属（Aurantiochytrium）等旋毛藻属已被开发并获得专利，作为 DHA 生产的工业菌株。高 DHA 产量归因于其独特且高效的聚酮合酶（PKS）途径。此外，旋毛藻具有完整的甲羟戊酸（MVA）途径，因此可作为萜烯类化合物生产的宿主。为了提高菌株性能，代谢工程策略已被应用于促进或破坏细胞内代谢途径，例如基因工程和添加化学激活剂。然而，仅通过提高菌株性能很难实现工业化。已经开发了各种操作策略来从实验室规模扩大生产数量，包括两阶段培养策略、放大技术和生物反应器设计。此外，经济高效的下游工艺也是旋毛藻工业应用的重要考虑因素。下游成本占总工艺成本的 20-60%，这是提高旋毛藻成本竞争力的一个有吸引力的目标，包括如何提高脂质提取效率和生物质残渣的进一步应用。本综述旨在概述旋毛藻的整个脂质生物技术，为研究人员提供背景信息。
