Abstract

Docosahexaenoic acid (DHA) is an essential dietary supplement that is highly coveted due to its benefits for human health. Extensive research has been conducted for the sustainable commercial production of DHA by various strains in thraustochytrid family due to the accumulation of higher lipid content in the cells. The current study is focused on improving DHA production by investigating various key enzymes like glucose-6-phosphate dehydrogenase (G6PDH), malic enzyme (ME), and ATP-citrate lyase (ACL) involved in DHA production using Thraustochytrium sp. T01. The growth of this strain was compared in batch and fed-batch mode. The fed-batch yielded better Dry cell weight (40 g L⁻¹), lipid (27.75 g L⁻¹ or 693 mg g⁻¹ of DCW), and DHA contents (11.10 g L⁻¹ or 277 mg g⁻¹ of DCW). G6PDH activity increased 4-fold during the glucose fed-batch, but ME and ACL did not increase significantly. Furthermore, a study was conducted to determine the effects of organic acids (pyruvate and malate) on key enzyme activities. The addition of pyruvate increased the lipid content by 1.35-fold, and ACL activity by 10-fold as compared with control (without added organic acids). Malate addition into the culture media increased DHA content 1.4-fold, and ME activity increased 14-fold compared with control.

摘要

二十二碳六烯酸 (DHA) 是一种必需的膳食补充剂，因其对人类健康的益处而备受追捧。由于破囊壶菌家族中的各种菌株在细胞中积累了较高的脂质含量，因此对 DHA 的可持续商业生产进行了广泛的研究。目前的研究重点是通过研究利用Thraustochytrium sp. 参与 DHA 生产的各种关键酶，如葡萄糖-6-磷酸脱氢酶 (G6PDH)、苹果酸酶 (ME) 和 ATP-柠檬酸裂解酶 (ACL) 来提高 DHA 产量。T01。在分批和补料分批模式下比较该菌株的生长。补料批次产生了更好的干细胞重量（40 g L ^-1）、脂质（27.75 g L ^-1或 693 mg g ^-1 DCW）和 DHA 含量（11.10 g L ^-1或 277 mg g ^-1 DCW ）。 DCW）。在葡萄糖补料分批期间，G6PDH 活性增加了 4 倍，但 ME 和 ACL 没有显着增加。此外，还进行了一项研究以确定有机酸（丙酮酸和苹果酸）对关键酶活性的影响。与对照（不添加有机酸）相比，添加丙酮酸使脂质含量增加1.35倍，ACL活性增加10倍。与对照相比，培养基中添加苹果酸使 DHA 含量增加 1.4 倍，ME 活性增加 14 倍。