一种新沼泽红假单胞菌鉴定及其类胡萝卜素含量分析

 通过观察实验室保藏的光合细菌X1的表观形态、生理特性以及采用16S rDNA序列对比的方法进行鉴定,采用超声波破碎法、酸-热破壁法和研磨法对X1中类胡萝卜素进行提取,并比较各种方法效果.用丙酮作为提取剂,进一步利用紫外分光光度法、薄层层析法和高效液相色谱(HPLC)法对类胡萝卜素提取液进行了分析.确定光合细菌X1属于紫色非硫细菌中的红罗菌科、红假单胞菌属,沼泽红假单胞菌(Rhodopsedomonas palustris);发现超声波浸提法提取类胡萝卜素效果最好,其次是酸-热破碎法和研磨法;X1中主要积累虾青素和一种未知色素,其中,虾青素含量为0.28mg/L.采用分光光度法在495nm下,总类胡萝卜素含量为2.125mg/g(干重).

Identification of Rhodopseudomonas palustris and Its Analysis for Carotenoids

This paper describes a kind of photosynthetic bacteria X1 from laboratory preservation. X1 has the ability to accumulate carotenoids naturally. The pigments were extracted by different methods to analyze the carotenoids' contents. Using morphological characters, physiological characters and 16s rDNA, X1 was identified. Then carotenoids were extracted by the ultrasonic extraction, acid-heat and grinding methods. Acetone was used as the solvent in the extraction. Furthermore, the ultraviolet spectrophotometry, the thin layer chromatography and the High Performance Liquid Chromatography (HPLC) system for the carotenoid extracts were analyzed. After appraisal, X1 was identified as Purple Non-Sulfur Bacteria, rhodospirillaceae, rhodopseudomonas, Rhodopsedomonas palustris. Comparing these extraction methods of carotenoids, it is shown that the ultrasonic extraction is the best method, followed by the acid-heat method. The grinding method is inferior to other two methods. As a result, Rhodopsedomonas palustris X1 can produce carotenoids up to 2.125mg/g (in dry weight) by the ultraviolet spectrophotometry at the wavelength of 495nm. The carotenoids have two main components, one of which is astaxanthin. The HPLC result shows that the astaxanthin content reaches 0.28mg/L in the extract.