Metabolite Profile Analysis of Aurantiochytrium limacinum SR21 Grown on Acetate-based Medium for Lipid Fermentation
| Autor: | Yoshiko Okamura, Tsunehiro Aki, Charose Marie Ting Perez, Kenshi Watanabe, Yutaka Nakashimada |
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| Rok vydání: | 2019 |
| Předmět: |
chemistry.chemical_classification
0303 health sciences 030309 nutrition & dietetics General Chemical Engineering Metabolite Glyoxylate cycle Fatty acid 04 agricultural and veterinary sciences General Medicine General Chemistry Pentose phosphate pathway 040401 food science Citric acid cycle 03 medical and health sciences chemistry.chemical_compound 0404 agricultural biotechnology chemistry Fermentation Food science Mevalonate pathway Fatty acid synthesis |
| Zdroj: | Journal of Oleo Science. 68:541-549 |
| ISSN: | 1347-3352 1345-8957 |
| DOI: | 10.5650/jos.ess19020 |
| Popis: | Thraustochytrids, a group of marine protists, are continuously gaining attention due to their capability in producing lipids for various biotechnological applications towards foods, medicines, chemicals, and biofuels. Although various substrates, predominantly glucose, have been used as carbon source for this microalga, it is desirable to adopt cheaper and more diversified substrate to expand their application range. In this study, we aimed to examine the ability of acetate, which can be easily generated from various resources by acetogenic microorganisms, as a substrate of Aurantiochytrium limacinum SR21. As a result of flask-scale analysis, specific growth rates (µ) of the strain SR21 grown in 3% acetate- or glucose-based medium were 0.55 and 0.98 h-1, respectively. The maximum yield of total fatty acid in acetate medium was 4.8 g/L at 48 h while that in glucose medium was 6.8 g/L at 30 h, indicating that acetate has potential as substrate. Metabolome analysis was performed to comprehensively elucidate characteristic metabolic fluctuations caused by acetate assimilation and identify targets to improve the fatty acid productivity from acetate. It was found that the use of glyoxylate cycle, which bypasses release of energy molecules such as NADH and GTP, and the inhibition of utilization of compounds from TCA cycle for anabolic reactions, may cause the slow growth in acetate which has an effect also in lipid productivity. The activity of the pentose phosphate pathway was found to be weak in acetate cultivation, thus NADPH was mainly produced in malate-pyruvate cycle. Lastly, mevalonate pathway was found to be activated in acetate cultivation which additionally competes with acetyl-CoA as starting material of fatty acid synthesis. |
| Databáze: | OpenAIRE |
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