A new strategy for strain improvement of Aurantiochytrium sp. based on heavy-ions mutagenesis and synergistic effects of cold stress and inhibitors of enoyl-ACP reductase
| Autor: | Gu-Zhen Cui, Zhijie Sun, Yu-rong Cheng, Xiaojin Song, Qiu Cui |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
0301 basic medicine Docosahexaenoic Acids Mutant Bioengineering Enoyl-(Acyl-Carrier Protein) Reductase (NADPH B-Specific) Reductase 01 natural sciences Applied Microbiology and Biotechnology Biochemistry 03 medical and health sciences chemistry.chemical_compound Stress Physiological 010608 biotechnology Fatty Acid Synthase Type II Isoniazid Enzyme Inhibitors Fatty acid synthesis Ions biology Mutagenesis Wild type Metabolism Triclosan Cold Temperature Fatty acid synthase 030104 developmental biology chemistry Docosahexaenoic acid Dietary Supplements Fermentation biology.protein Stramenopiles Biotechnology |
| Zdroj: | Enzyme and microbial technology. |
| ISSN: | 1879-0909 |
| Popis: | Developing a strain with high docosahexaenoic acid (DHA) yield and stable fermenting-performance is an imperative way to improve DHA production using Aurantiochytrium sp., a microorganism with two fatty acid synthesis pathways: polyketide synthase (PKS) pathway and Type I fatty acid synthase (FAS) pathway. This study investigated the growth and metabolism response of Aurantiochytrium sp. CGMCC 6208 to two inhibitors of enoyl-ACP reductase of Type II FAS pathway (isoniazid and triclosan), and proposed a method of screening high DHA yield Aurantiochytrium sp. strains with heavy ion mutagenesis and pre-selection by synergistic usage of cold stress (4°C) and FAS inhibitors (triclosan and isoniazid). Results showed that (1) isoniazid and triclosan have positive effects on improving DHA level of cells; (2) mutants from irradiation dosage of 120Gy yielded more DHA compared with cells from 40Gy, 80Gy treatment and wild type; (3) DHA contents of mutants pre-selected by inhibitors of enoyl-ACP reductase of Type II FAS pathway (isoniazid and triclosan)at 4°C, were significantly higher than that of wild type; (4) compared to the wild type, the DHA productivity and yield of a mutant (T-99) obtained from Aurantiochytrium sp. CGMCC 6208 by the proposed method increased by 50% from 0.18 to 0.27g/Lh and 30% from 21 to 27g/L, respectively. In conclusion, this study developed a feasible method to screen Aurantiochytrium sp. with high DHA yield by a combination of heavy-ion mutagenesis and mutant-preselection by FAS inhibitors and cold stress. |
| Databáze: | OpenAIRE |
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