Research
| Title： | Overexpression of the sulfate transporter-encoding SULTR2 increases chromium accumulation in Chlamydomonas reinhardtii |
|---|---|
| First author： | Tang, Yuxin; Zhang, Baolong; Li, Zhaoyang; Deng, Ping; Deng, Xuan; Long, Huan; Wang, Xun; Huang, Kaiyao |
| Journal： | BIOTECHNOLOGY AND BIOENGINEERING |
| Years： | 2023 |
| DOI： | 10.1002/bit.28350 |
| Abstract： | Hexavalent chromium [Cr(VI)] is a highly toxic contaminant in aquatic systems, and microalgae represent promising bioremediators of metal-containing wastewater. However, the metal-binding capacity of algal cells is limited. Therefore, we improved the cellular Cr(VI) biosorption capacity of Chlamydomonas reinhardtii by over-expressing the sulfate transporter gene SULTR2. SULTR2 was predominantly located in the cytoplasm of the cell, and few proteins mobilized to the cell membrane as a Cr transporter under Cr stress conditions. Intracellular Cr accumulation was almost doubled in SULTR2-overexpressing transgenic strains after exposure to 30 mu M K2Cr2O7 for 4 d. Alginate-based immobilization increased the rate of Cr removal from 43.81% to 88.15% for SULTR2-overexpressing transgenic strains after exposure to 10 mu M K2Cr2O7 for 6 d. The immobilized cells also displayed a significant increase in nutrient removal efficiency compared to that of free-swimming cells. Therefore, SULTR2 overexpression in algae has a great potential for the bioremediation of Cr(VI)-containing wastewater. |
