Department of Chemical Engineering and Center of Food Biotechnology and Bioseparations, BIOREN, Universidad de La Frontera, Casilla 54-D, Temuco, Chile.
Centre for Biotechnology and Bioengineering (CeBiB), Universidad de La Frontera, Temuco, Chile.
Mar Biotechnol (NY). 2019 Feb;21(1):99-110. doi: 10.1007/s10126-018-9863-z. Epub 2018 Nov 19.
Total lipids and docosahexaenoic acid (DHA) production by a Chilean isolated thraustochytrid were evaluated under different growth conditions in shake flasks. The analyzed strain was identified as Thraustochytrium striatum according to an 18S rRNA gene sequence analysis. The strain (T. striatum AL16) showed negligible growth in media prepared with artificial seawater at concentrations lower than 50% v/v and pH lower than 5. Maltose and starch were better carbon sources for growth than glucose. DHA content of the biomass grown with maltose (60 g L) was doubled by increasing the agitation rate from 150 to 250 rpm. The DHA (0.8-6%) and eicosapentaenoic acid (0.2-21%) content in the total lipids varied depending on culture conditions and culture age. Lipid and DHA concentration increased (up to 5 g L and 66 mg L, respectively) by regularly feeding the culture with a concentrated starch solution. Carotenoid accumulation was detected in cells grown with maltose or starch. Contrasting conditions of starch and glucose cultures were selected for comparative proteomics. Total protein extracts were separated by two-dimensional gel electrophoresis; 25 spots were identified using ESI-MS/MS. A protein database (143,006 entries) for proteomic interrogation was generated using de novo assembling of Thraustochytrium sp. LLF1b - MMETSP0199_2 transcriptome; 18 proteins differentially expressed were identified. Three ATP synthases were differentially accumulated in cultures with glucose, whereas malate dehydrogenase was more abundant in cells cultured with starch.
在摇瓶中，根据不同的生长条件评估了智利分离的裂殖壶菌的总脂质和二十二碳六烯酸（DHA）的生产。根据 18S rRNA 基因序列分析，分析的菌株被鉴定为裂殖壶菌（Thraustochytrium striatum）。该菌株（T. striatum AL16）在浓度低于 50%（v/v）的人工海水中和 pH 低于 5 的培养基中生长缓慢。与葡萄糖相比，麦芽糖和淀粉是更好的生长碳源。通过将搅拌速度从 150 增加到 250 rpm，用麦芽糖（60 g/L）培养的生物量的 DHA 含量增加了一倍。在总脂质中，DHA（0.8-6%）和二十碳五烯酸（0.2-21%）的含量取决于培养条件和培养龄。通过定期用浓缩淀粉溶液喂养培养物，脂质和 DHA 浓度增加（分别增加到 5 g/L 和 66 mg/L）。在以麦芽糖或淀粉生长的细胞中检测到类胡萝卜素的积累。选择了淀粉和葡萄糖培养的对比条件进行比较蛋白质组学研究。使用 ESI-MS/MS 鉴定了 25 个点。使用 Thraustochytrium sp. LLF1b-MMETSP0199_2 转录组从头组装生成蛋白质数据库（143006 个条目），用于蛋白质组学询问；鉴定出 18 个差异表达的蛋白质。在葡萄糖培养物中差异积累了三种 ATP 合酶，而在淀粉培养物中苹果酸脱氢酶更为丰富。
