Abstract:

The fluorescent pigment secreted by Pseudomonas syringae is a principal characteristic for bacteria classification, identification, and also one of potential virulence-related factors. In this study, we determined the impact of different concentrations of minimal medium components on production of P. syringae fluorescent pigment biosynthesis; and compared the influence of several iron-ion chelators on recovering biosynthesis ability of fluorescent pigment in pseudomonas syringaes and bacterial growth. The results indicated that ① concentration of iron-ion was the most significant impact-factor, which could influence colony fluorescence of P. syringae on KB medium, while the concentration of proteose peptone, K2HPO4 and MgSO4 could not obviously affect colony fluorescence. ②The production of P. syringae fluorescent pigments could get restored on KB plates and be significantly promoted in KB liquid when iron-ion specific chelator 8-hydroxyquinoline added at the concentration of 0.05 g/L, with a slight inhibition on bacterial growth. However, this recovery by 8-hydroxyquinoline could be reversed by adding FeCl3 at concentration of 0.05 g/L. ③Other metal-ion chelators, such as citric acid, tartaric acid sodium, trisodium phosphate and ethylenediaminetetraacetic acid disodium, could not restore P. syringae colony fluorescence. Therefore, adding iron-ion specific chelator 8-hydroxyquino (0.05 g/L) to KB medium was a more practical method for restoring colony fluorescence of P. syringae.

Key words: Pseudomonas syringae, iron-ion chelator, 8-hydroxyquinoline, biosynthesis of fluorescent pigment

摘要：

丁香假单胞菌产生的荧光色素是一种具有毒性功能的致病性因子,也是细菌鉴定和分类的重要依据。测定了基本培养基不同组分的浓度对丁香假单胞菌荧光色素产生能力的影响,并比较了几种金属离子螯合剂对恢复丁香假单胞菌荧光物质合成能力以及细菌生长能力的影响,旨在找到恢复丁香假单胞菌在常规培养基上合成荧光色素的方法。结果如下:①丁香假单胞菌荧光色素的合成能力主要受培养基中铁离子浓度的影响,而与眎蛋白胨,以及K2HPO4、MgSO4的浓度均无关；② 0.05 g/L的螯合剂8-羟基喹啉可使丧失荧光物质合成能力的丁香假单胞菌恢复产生荧光,恢复的荧光物质合成可以被铁盐（FeCl3）逆转；但同时8-羟基喹啉对细菌生长也有一定的抑制作用；③其他金属离子螯合剂,如柠檬酸(C6H8O7·H2O)、酒石酸钠(Na2C4H4O6)、磷酸三钠(Na3PO4)和乙二胺四乙酸二钠(EDTA-Na2),均不能恢复丁香假单胞菌产荧光色素。该结果表明在KB培养基中添加螯合剂8-羟基喹啉（0.05 g/L）可以使丁香假单胞菌恢复荧光物质的合成能力。

关键词: 丁香假单胞菌;铁离子螯合剂;8-羟基喹啉;荧光物质合成