Colin Ratledge Center for Microbial Lipids, School of Agriculture Engineering and Food Science, Shandong University of Technology, Zibo, China; Interdisciplinary Graduate Programs in Bioscience, Faculty of Science, Kasetsart University, Bangkok, Thailand.
Institute of Nutrition, Mahidol University, Nakhon Pathom, Thailand.
Gene. 2022 Dec 20;846:146850. doi: 10.1016/j.gene.2022.146850. Epub 2022 Aug 28.
Aurantiochytrium sp., a fungoid marine protist that belongs to Stramenophila has proven its potential in the production of polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acids (DHA). In this study, genomic characterisation of a potential producer for commercial production of DHA, Aurantiochytrium sp. SW1 has been carried out via whole genome sequencing analysis. The genome size of this strain is 60.89 Mb, with a total of 11,588 protein-coding genes. Among these, 9,127 genes could be functionally annotated into a total of 7,248 (62.5 %) from UniProt, 6,554 (56.6 %) from KEGG and 8,643 (74.6 %) genes from eggNOG protein database. The highest proportion of genes belongs to the protein family of metabolism were further assigned into 11 metabolic categories. The highest number of genes belonging to lipid metabolism (321 genes) followed by carbohydrate metabolism (290 genes), metabolism of cofactors and vitamins (197 genes) and amino acid metabolism (188 genes). Further analysis into the biosynthetic pathway for DHA showed evidence of all genes involved in PKS (polyketide synthase)-like PUFA synthase pathway and incomplete fatty acid synthase-elongase/desaturase pathway. Analysis of PUFA synthase showed the presence of up to ten tandem acyl carrier protein (ACP) domains which might have contributed to high DHA production in this organism. In addition, a hybrid system incorporating elements of FAS, Type I PKS and Type II PKS systems were found to be involved in the biosynthetic pathways of fatty acids in Aurantiochytrium sp. SW1. This study delivers an important reference for future research to enhance the lipid, especially DHA production in Aurantiochytrium sp, SW1 and establishment of this strain as an oleaginous thraustochytrid model.
球形棕囊藻是一种属于不等鞭毛门的海洋真菌原生生物，已被证明在多不饱和脂肪酸（PUFAs），特别是二十二碳六烯酸（DHA）的生产方面具有潜力。在这项研究中，通过全基因组测序分析，对一种用于商业生产 DHA 的潜在生产菌球形棕囊藻 SW1 进行了基因组特征分析。该菌株的基因组大小为 60.89Mb，共有 11588 个蛋白质编码基因。其中，9127 个基因可以在 UniProt 中被功能注释为总共 7248 个（62.5%），在 KEGG 中被注释为 6554 个（56.6%），在 eggNOG 蛋白质数据库中被注释为 8643 个（74.6%）。属于代谢途径的蛋白质家族的基因比例最高，进一步被分配到 11 种代谢类别中。属于脂质代谢的基因数量最多（321 个），其次是碳水化合物代谢（290 个）、辅助因子和维生素代谢（197 个）和氨基酸代谢（188 个）。对 DHA 生物合成途径的进一步分析表明，所有参与聚酮合酶（polyketide synthase）样多不饱和脂肪酸合酶途径和不完全脂肪酸合酶-延伸酶/去饱和酶途径的基因都存在证据。对多不饱和脂肪酸合酶的分析表明，存在多达十个串联酰基载体蛋白（ACP）结构域，这可能有助于该生物体内 DHA 的高产量。此外，还发现了一个包含 FAS、I 型 PKS 和 II 型 PKS 系统元素的混合系统，参与了球形棕囊藻 SW1 中脂肪酸的生物合成途径。这项研究为未来的研究提供了重要的参考，以提高球形棕囊藻 SW1 的脂质，特别是 DHA 的产量，并建立该菌株作为产油海洋毛霉的模型。
