Center for Viticulture and Enology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, People's Republic of China.
Curr Microbiol. 2011 Mar;62(3):1056-61. doi: 10.1007/s00284-010-9826-8. Epub 2010 Dec 1.
The effect of H(2)O(2) supplement on cell growth and β-carotene productions in recombinant Saccharomyces cerevisiae CFW-01 and CFW-01 ctt1 deficiency in cytosolic catalase were investigated in shaking flasks. The results showed that supplement of H(2)O(2) (0.5 and 1.0 mM) can significantly stimulate the β-carotene production. However, β-carotene levels of CFW-01 ctt1Δ under 0.5 and 1 mM H(2)O(2) were 16.7 and 36.7% lower than those of CFW-01, respectively. Although lacking cytosolic catalase, no significant differences in cell growth were observed between CFW-01 ctt1Δ and CFW-01 under the same level of H(2)O(2) stress. These results suggest that β-carotene can act as an antioxidant to protect the recombinant yeast from H(2)O(2) oxidative damage in the absence of cytosolic catalase. However, catalase still plays an important role in the production of β-carotene under H(2)O(2) stress. If catalase can not timely decompose H(2)O(2), the free radicals such as OH· derived from H(2)O(2) can result in decrease of β-carotene concentration. Therefore, in the production of β-carotene by H(2)O(2) stress, not only the level of oxidative stress, but also the activities of catalase in cells should be considered.
研究了在摇瓶中添加 H(2)O(2)对重组酿酒酵母 CFW-01 和胞质过氧化物酶体缺陷型 CFW-01 ctt1Δ细胞生长和 β-胡萝卜素产量的影响。结果表明，添加 H(2)O(2)(0.5 和 1.0 mM)可显著刺激 β-胡萝卜素的产生。然而，在 0.5 和 1 mM H(2)O(2)下，CFW-01 ctt1Δ的 β-胡萝卜素水平分别比 CFW-01 低 16.7%和 36.7%。尽管缺乏胞质过氧化物酶体，但在相同水平的 H(2)O(2)胁迫下，CFW-01 ctt1Δ和 CFW-01 的细胞生长没有明显差异。这些结果表明，β-胡萝卜素可以作为抗氧化剂，在缺乏胞质过氧化物酶体的情况下保护重组酵母免受 H(2)O(2)的氧化损伤。然而，过氧化氢酶在 H(2)O(2)胁迫下产生 β-胡萝卜素仍然起着重要的作用。如果过氧化氢酶不能及时分解 H(2)O(2)，H(2)O(2)衍生的自由基如 OH·会导致 β-胡萝卜素浓度降低。因此，在 H(2)O(2)胁迫下生产 β-胡萝卜素时，不仅要考虑氧化应激水平，还要考虑细胞中过氧化氢酶的活性。
