以纳豆发酵豆渣为原料的红法夫酵母产虾青素特征分析及免疫功效评价

Characteristic analysis and immunological effect evaluation of astaxanthin produced by Phaffia rhodozyma using natto-fermented okara as raw material

中文关键词:  红法夫酵母  虾青素  豆渣  纳豆  斑马鱼

英文关键词:Phaffia rhodozyma  Astaxanthin  Okara  Natto  Zebrafish

中文摘要:

      目的 为了探究纳豆发酵豆渣对红法夫酵母产虾青素的影响,及生产的虾青素对斑马鱼的生长及免疫调节作用。方法 采用虾青素含量和活菌数指标分析红法夫酵母增产虾青素的特征水平,采用蛋白含量及分子量大小、氨基酸、酸性洗涤纤维、酸性洗涤木质素、总糖、葡萄糖等指标分析纳豆发酵豆渣的变化情况,斑马鱼体重、体长、肿瘤坏死因子α(Tumor Necrosis Factor-α,TNF-α)和白细胞介素(Interleukin-1β,IL-1β)等指标虾青素的免疫调节水平,偏最小二乘法判别模型分析(Partial Least Squares-Discriminant Analysis,PLS-DA)综合评价虾青素对斑马鱼促进免疫的差异水平。结果 以纳豆发酵处理豆渣为唯一氮源可显著提高红法夫酵母细胞量和产虾青素水平,豆渣经纳豆发酵后,粗蛋白、氨基酸总量和总游离氨基酸分别由发酵前的18.38%、16.18%和0.57%显著提升至18.96%、16.94%和0.88%,蛋白质分子量显著下降,酸性洗涤纤维由发酵前的26.64%下降至25.95%,粗脂肪由发酵前的3.52%下降到2.16%。红法夫酵母产虾青素的最佳工艺组合为:纳豆发酵干豆渣加入量1.5 %(w/v)、葡萄糖与蔗糖1:1混合物加入量20 g/L,处理豆渣及优化配方后获得红法夫酵母虾青素产量为35.92 mg/L,显著高于Con值19.62 mg/L,产量提升了83.08%。斑马鱼生长和免疫调节实验表明,当虾青素加入量为50～100 mg/kg时,斑马鱼的体重、IL-1β因子显著高于未加虾青素的Con组,虾青素浓度为10～100 mg/kg时,其TNF-α均显著高于对照组,PLS-DA分析表明个处理间存在显著差异,表明虾青素的添加特别是终浓度大于50 mg/kg,对斑马鱼有显著的促生长和免疫调节作用。结论 经过纳豆发酵后的豆渣及工艺优化可显著提升红法夫酵母产虾青素的水平,获得的虾青素有利于促进斑马鱼的生长和免疫调节作用。

英文摘要:

      ABSTRACT: Objective To investigate the effect of natto-fermented okara on the production of astaxanthin by Phaffia rhodozyma and the immunomodulatory effects of the produced astaxanthin on zebrafish. Methods The characteristic levels of astaxanthin production by Phaffia rhodozyma were analyzed using astaxanthin content and viable count as indicators. The changes in natto-fermented okara were analyzed using indicators such as protein content and molecular weight, amino acids, acid detergent fiber, acid detergent lignin, total sugar, and glucose. The immunomodulatory effects of astaxanthin were evaluated based on zebrafish body weight, body length, tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β). Partial least squares-discriminant analysis (PLS-DA) was used to comprehensively evaluate the difference in immune promotion effects of astaxanthin on zebrafish. Results Using natto-fermented okara as the sole nitrogen source significantly increased the cell mass and astaxanthin production of Phaffia rhodozyma. After natto fermentation, the crude protein, total amino acid, and total free amino acid in the okara increased significantly from 18.38%, 16.18%, and 0.57% before fermentation to 18.96%, 16.94%, and 0.88%, respectively. The protein molecular weight decreased significantly, and the acid detergent fiber decreased from 26.64% to 25.95% before fermentation. The crude fat decreased from 3.52% to 2.16% before fermentation. The optimal process combination for astaxanthin production by Phaffia rhodozyma was: 1.5% (w/v) of natto-fermented okara, 20 g/L of a 1:1 mixture of glucose and sucrose. After processing the okara and optimizing the formula, the astaxanthin yield of Phaffia rhodozyma reached 35.92 mg/L, significantly higher than the control value of 19.62 mg/L, with an increase of 83.08%. Experiments on the growth and immunomodulation of zebrafish showed that when the astaxanthin addition was 50-100 mg/kg, the body weight and IL-1β factor of zebrafish were significantly higher than those of the control group without astaxanthin. When the astaxanthin concentration was 10-100 mg/kg, TNF-α was significantly higher than that of the control group. PLS-DA analysis showed significant differences between treatments, indicating that the addition of astaxanthin, especially at a final concentration greater than 50 mg/kg, had significant growth-promoting and immunomodulatory effects on zebrafish. Conclusion Natto-fermented okara and process optimization can significantly improve the astaxanthin production level of Phaffia rhodozyma, and the obtained astaxanthin is conducive to promoting the growth and immunomodulatory effects of zebrafish.