深層海水與其主要離子對硒酵母生長與有機硒含量之影響

The Effects of Deep Sea Water and Its Major Ions on the Growth and Organic Selenium Production of Selenium-Enriched Yeast

硒酵母（selenium-enriched yeast）是藉由酵母菌在發酵過程中對硒的利用，將生理活性低的無機硒轉化為高生理活性之有機硒，並去除無機硒的副作用與危害。許多研究證實，硒酵母具有預防和抑制腫瘤、提高免疫機能、抗衰老與預防動脈硬化之發生。深層海水（deep sea water, DSW）富含無機鹽類與微量元素，過去的研究已證實具有促進酵母菌、紅麴菌與樟芝菌之生長與代謝物生成之能力，並提升其保健功效。基於DSW 對於微生物發酵之優勢，本研究將探討深層海水之各主要離子對於硒酵母生長與有機硒轉換之影響，並藉由反應曲面法（response surface methodology, RSM）探討硒酵母之最適培養條件與大規模生產技術。本研究在不同濃度之DSW 試驗中，1 倍濃度之DSW 有助於胞內硒含量之總生成；不同離子對硒酵母之菌體量與其硒含量之影響試驗中發現，Na+、Ca2+ 與Fe2+ 有助於硒含量之累積，進而以反應曲面法調整DSW 中Na+、Ca2+ 及Fe2+ 之濃度以期望獲得最高之硒含量。結果顯示，當Na+ 離子濃度為17.42 mg/L、Ca2+離子濃度為0.855 mg/L、Fe2+ 離子濃度為0.0493 μg/L 時為最適培養條件，與超純水（ultra-pure water, UPW）相比，其菌體量可由0.347g 提升至0.359g，產量可由0.308 mg/batch 提升至0.987 mg/batch 之硒含量；於進一步的1.5-L 之放大培養，其菌體量由4.825g 提升至4.991g，產量可由4.118 mg/batch 提升至5.912mg/batch 之硒含量。

Selenium-enriched yeast (Se-yeast) is produced by the conversion of Se from inorganic state organic state during the fermentation in order to raise the physiological function and detoxification of Se. However, Se-yeast has been proven to prevent the development of cancer, aging, and cardiovascular disease, as well as raise the immune function. Deep sea water (DSW) with rich in inorganic salts and trace elements was proven to stimulate the growth and metabolites biosynthesis in yeast, Monascus, and Antrodia camphorata, and further promote the health function, Based on the advantage of DSW on the fermentation, this study is to use DSW to culture yeast for raising the biomass and the organic Se content of Se-yeast. Furthermore, the major ions of DSW were used to investigate the effect on the kinetic of growth and the organic Se bioconversion of Se-yeast. Finally, the optimal culture condition and large scale fermentation were investigated via response surface methodology. In the results of the effect of various concentration of DSW, 1X-DSW concentration was benefit to the production of organic Se. According to effect of various ions on the production of intracellular organic Se and biomass, Na+, Ca2+, and Fe2+ were the functional ions for the accumulation of organic Se content. In further, RSM was used to modulate the concentration of Na+, Ca2+, and Fe2+ in DSW for obtaining the highest organic Se production. However, the biomass production was raised from 0.347 g to 0.359 g. The organic Se production was raised from 0.308 mg/batch to 0.987 mg/batch using 17.42 mg/L Na+, 0.855 mg/L Ca2+, and Fe2+ 0.0493 μg/L as the optimal concentration of ion addition, as compared with UPW group. Furthermore, the biomass production was increased from 4.825 g to 4.991 g. Organic Se production was raised from 4.118 mg/ batch to 5.912 mg/batch under 1.5-L fermenter.