高产胡萝卜素红酵母的筛选及培养条件的优化研究-四川农业大学.docVIP

高产类胡萝卜素红酵母的筛选及发酵条件的优化 生物科学 2003级 任 君 指导教师 黄乾明 教 授 摘要：从自然环境中分离到15株产类胡萝卜素的酵母菌，通过测定和比较其发酵后的生物量、类胡萝卜素含量及产量，从中筛选出1株产类胡萝卜素能力较强的菌株3-2，经形态和生理生化鉴定为红酵母（Rhodotorula sp.），其所产色素经硫酸显色反应和光谱分析鉴定主要为β-胡萝卜素。进一步研究其产类胡萝卜素的最适碳源和氮源，并用正交设计试验对其主要营养与环境条件进行优化，初步确定该菌株的最佳发酵条件为：葡萄糖30g/L，蛋白胨5g/L，酵母粉5g/L，装瓶量30mL/250mL，起始pH6.5，发酵温度28℃，发酵时间96h。在此发酵条件下其生物量、类胡萝卜素含量和产量分别达到17.6g/L，639.8μg/g，11.3mg/L。 关键词：类胡萝卜素，红酵母，筛选，发酵条件 Screening of Rhodotorula Producing Carotenoid and Optimizing Its Fermentation Conditions REN Jun Biological Science, Grade 2003 Directed by HUANG Qian-ming (Prof. Ph. D) Abstract : 15 yeast strains, isolated and screened from the natural environment, were able to produce carotenoid, and the strain 3-2 with high carotenoid yield of 8.6 mg/L was obtained from these yeasts by common screening test. The strain 3-2 was identified as Rhodotorula sp. by morphologic and physiology. And the pigment was identified primarily as β-carotene by color reaction and spectral analysis. This paper optimizes its fermentation conditions of RY3-2 which produce carotenoid, and the varied physiological conditions for carotenoid fermentation were investigated by orthogonal design test method. The cell biomass, carotenoid content and yield from strain RY3-2 could respectively reach 17.8g/L, 657.6μg/g and 11.4mg/L under the selected optimum conditions. The optimum fermentation conditions for carotenoid production were as follows: glucose 30 g/L, tryptone 10 g/L, yeast extract 5 g/L, medium 30 mL (in 250 mL flask), initial pH 6.5 and culture time 96h at 28 ℃ and 150 r/min. Keywords : carotenoid, Rhodotorula, screening, fermentation conditions 类胡萝卜素（Carotenoid）是一类广泛存在于自然界中的天然有色物质[1]，通常是指40碳的碳氢化合物（胡萝卜素）和它们的氧化衍生物（叶黄素）两大类色素的总称，其颜色通常为黄色到红色，属于脂溶性四萜烯类化合物。到目前为止，已知的类胡萝卜素约600多种，很多天然类胡萝卜素来自高等植物橙黄色的花朵（如：向日葵、金盏花等）、橙红色的果实（如：番茄、柑橘等）以及胡萝卜的根。但是类胡萝卜素含量最高的是微生物、植物和藻类的光合组织[2, 3]。类胡萝卜素一般可分为两类：胡萝卜素和叶黄素。前者以β-胡萝卜素为代表，仅含碳、氢两种元素，后者则是前者的含氧衍生物，如虾青素。另一种分类系统是将类胡萝卜素分为链状、单环和双环衍生物，它们的母体代表化合物分别为：γ-胡萝卜素、番茄红素和β-胡萝卜素[4]。类胡萝卜素的性质由它的分子结构决定，共轭多烯链