利用拉曼光谱原位定量检测技术筛选红酵母类胡萝卜素高产突变株

Screening of Carotenoid High-Producing Mutants from Rhodotorula Glutinis Using Raman Spectroscopy in Situ Quantitative Detection Technology

建立了一种利用显微拉曼光谱原位定量技术筛选平板培养基上类胡萝卜素高产突变株的方法。为了消除培养基背景信号对定量结果的影响,采用矢量校正算法对光谱数据进行预处理,得到了不含培养基干扰的菌落净信号。比较了不同光谱收集方式对光谱重现性的影响,发现扫描方式较定点检测能获得重现性更好的菌落净信号。利用共焦显微拉曼光谱分析了平板培养基上红酵母菌落中的类胡萝卜素,并用光镊拉曼光谱法进行验证,两种方法所得类胡萝卜素1512cm-1拉曼峰值呈现良好的线性关系,说明了共焦显微拉曼光谱定量检测平板培养基上菌落内类胡萝卜素的可行性。用该方法对红酵母诱变菌进行筛选,筛选出两株类胡萝卜素高产菌株。研究结果表明该菌种筛选方法比传统方法更客观、高效。

A method is established based on micro-Raman spectroscopy in situ quantitative detection technology for the screening of carotenoid high-producing mutants from rhodotorula glutinis colonies growing on solid culture medium. In order to eliminate the interference of medium background signal with the quantitative results, vector correction algorithm is used to preprocess spectral data to obtain pure bacterial signal without medium interference. The effect of two different spectral collection modes on spectral repeatability is investigated. The results show that spectral signal collected with area-scan excitation mode can possess better repeatability than with fixed-point detection. Confocal micro-Raman spectroscopy is applied to estimate carotenoid content of rhodotorula glutinis colonies on solid culture medium, which is verified by laser tweezers Raman spectroscopy. A good correlation between carotenoid Raman peak intensities at 1512 cm-1 by above two approaches is observed. The data indicate that confocal micro-Raman spectroscopy is a reliable approach for the quantitative analysis of carotenoids in rhodotorula glutinis colonies on solid culture medium. Two carotenoid high-producing variants are obtained with the screening procedure established above. This evidence confirms that the proposed strains screening method is more objective and efficient than conventional methods.