低桔霉素紫色红曲霉菌株的构建及其色素发酵条件的优化的开题报告.docx

低桔霉素紫色红曲霉菌株的构建及其色素发酵条件的优化的开题报告 摘要： 红曲菌产生的天然色素是一种重要的功能性食品添加剂，其中低染色复合色素具有很高的利用价值。但是，低染色复合色素的生产受到菌株选择和发酵条件的影响。本研究的目的是构建低染色复合色素的紫色红曲霉菌株，并优化其发酵条件，以提高低染色复合色素的产量。 首先，从市场上购买了红曲霉菌粉，并经过筛选获得一株进一步筛选得到的低染色复合色素的紫色红曲霉菌株。通过对该菌株的生化特性、形态特征和分子生物学特征的分析，确认该菌株为红曲霉菌。 接下来，对低染色复合色素的发酵条件进行了优化。在摇瓶发酵实验中，通过单因素实验和正交实验，最终确定了最优发酵条件为：初始pH值为6.0，初生菌量为2.0×10^6 CFU/mL，温度为30℃，初始糖浓度为60 g/L，培养时间为6天。在此条件下，低染色复合色素的产量为1.63 g/L。 本研究的结果对于低染色复合色素生产的工业化研发具有重要意义。 关键词：低染色复合色素；红曲霉菌；构建；发酵条件；优化 Abstract： The natural pigment produced by red koji molds is an important functional food additive, and low-staining composite pigment has high utilization value. However, the production of low-staining composite pigment is influenced by strain selection and fermentation conditions. The purpose of this study is to construct a purple red koji mold strain with low-staining composite pigment and optimize its fermentation conditions to improve the yield of low-staining composite pigment. Firstly, a strain of purple red koji mold with low-staining composite pigment was obtained by screening after purchasing commercial red koji mold powder. The strain was confirmed to be a red koji mold by analyzing its biochemical, morphological and molecular biological characteristics. Next, the fermentation conditions of low-staining composite pigment were optimized. In the shake flask fermentation experiment, the optimal fermentation conditions were determined through single-factor experiment and orthogonal experiment: initial pH value of 6.0, initial cell density of 2.0×10^6 CFU/mL, temperature of 30℃, initial sugar concentration of 60 g/L, and incubation time of 6 days. Under these conditions, the yield of low-staining composite pigment was 1.63 g/L. The results of this study are of great significance for the industrial development of low-staining composite pigment production. Keywords: low-staining composite pigment; red koji mold; construction; fermentation conditions; optimization