基于简便快速的尼罗红荧光染色法建立高油脂裂殖壶菌筛选方法

裂殖弧菌是商业化生产二十二碳六烯酸（DHA）的重要菌株。为了快速检测裂殖壶菌细胞油脂含量，本文基于尼罗红荧光染色法，系统地筛选了激发光与发射光，并探究了简化细胞处理步骤，在不使用磷酸缓冲盐溶液洗涤细胞的条件下，优化二甲基亚砜（DMSO）体积分数、尼罗红用量、染色时间及细胞密度等因素对裂殖壶菌胞油脂检测的影响，并通过气相色谱法与荧光染色法的相关性分析，验证该方法的准确性。结果表明背景荧光未对荧光强度测定造成干扰；细胞密度在一定范围内，荧光强度与油脂含量的相关性良好，通过荧光强度可以较为准确地反映裂殖壶菌油脂含量。最佳染色及检测条件为：细胞密度0.7

Simplified and rapid lipid determination of Schizochytrium sp. by optimized Nile red fluorescence staining

Schizochytrium sp. is an important strain for commercial production of docosahexaenoic acid (DHA). Improving DHA production by physicochemicalmutagenesis is an important link in the development of microbial fermentation DHA industry. In order to establish a rapid optimal Nile red fluorescence staining method for determin?ing the lipid content in Schizochytrium sp., we systematically examined the effect of excitation wavelength, emission wavelength and explored the condition of cells without phosphate buffer solution washing. We also optimized the concentration of dimethyl sulfoxide (DMSO) and Nile red, staining time and cell density. The results showed that the culturing medium did not interfere with the determination of fluorescence intensity. In addition, we evaluated the correlation between the florescence intensity of Nile red staining and gas chromatographic method. The lipid content was positively correlated to the fluorescence intensity, when the cell density was within a certain range. We con? clude that lipid content of Schizochytrium sp. can be effectively determined by fluorescence intensity. The optimal conditions for determining of lipid content in Schizochytrium sp were obtained as follows : cell density was 0.7