油菜内生阿氏芽孢杆菌鉴定及其对铬(Ⅲ)处理反应性分析

Identification and Reactivity Analysis to Cr(Ⅲ)Treatment of Bacillus aryabhattai from Brassica napus L.

为探明耐铬(Ⅲ)油菜内生菌BNC-Q菌株对铬(Ⅲ)处理的生理生化反应性特点,以BNC-Q菌株为研究对象,进行了菌种鉴定以及铬(Ⅲ)处理反应性分析等试验。16S rDNA PCR分析结果表明,BNC-Q菌株为阿氏芽孢杆菌。铬(Ⅲ)胁迫培养试验结果表明,BNC-Q对铬(Ⅲ)耐受较强,可在5 mmol/L铬(Ⅲ)浓度条件下保持繁殖能力,可被不高于2 mmol/L的铬(Ⅲ)促进生长繁殖。蛋白质表达分析试验结果表明,经2 mmol/L铬(Ⅲ)处理后,BNC-Q可特异表达出一条约40 ku大小的蛋白质条带。抗氧化性分析试验结果表明,2 mmol/L铬(Ⅲ)处理对BNC-Q菌株清除DPPH自由基的能力基本无影响,但其对超氧阴离子自由基(O-·2)和羟基自由基(·OH)的清除率分别由63.7%,63.5%上升到91.1%,85.2%。综上所述,BNC-Q菌株为阿氏芽孢杆菌,对铬(Ⅲ)耐受性较强,可被铬(Ⅲ)诱导表达约40 ku的特异蛋白,铬(Ⅲ)诱导处理可显著提高其清除超氧阴离子自由基和羟基自由基的能力。研究结果可为重金属铬的生物修复研究提供一定的基础。

In order to verify the characteristics of physiological and biochemical response to Cr(Ⅲ),the chromium(Ⅲ)-resistant endophytic bacterium strain BNC-Q,which was isolated from Brassica napus L.in previous research,has been identified and been studied for its reactivity to Cr(Ⅲ)treatment.The strain BNC-Q was identified as Bacillus aryabhattai based on 16S rDNA PCR amplication analysis.The reproduction of BNC-Q being promoted by no more than 2 mmol/L Cr(Ⅲ)and still being available at 5 mmol/L Cr(Ⅲ)concentration showed that BNC-Q had a high tolerance to Cr(Ⅲ)based on the Cr(Ⅲ)treatment culture test.Protein expression analysis showed that a 40 ku protein was induced from BNC-Q with 2 mmol/L Cr(Ⅲ)treatment.The results of antioxidant analysis showed that BNC-Q had no effect on DPPH radical scavenging,while the scavenging rate of superoxide anion radical(O-·2)and hydroxyl radical(·OH)was increased from 63.7%,63.5% to 91.1%,85.2% respectively with 2 mmol/L Cr(Ⅲ)treatment.In summary,BNC-Q with strong tolerance to Cr(Ⅲ)was identified as Bacillus aryabhattai,and could be induced to express a 40 ku protein by Cr(Ⅲ),while the ability of scavenging superoxide anion radical and hydroxyl radical was significantly improved by Cr(Ⅲ).The research results can provide a basis for the bioremediation of Cr.