荧光假单胞菌RB5产嗜铁素的发酵条件

FERMENTATION CONDITIONS OF SIDEROPHORE PRODUCED BY PSEUDOMONAS FLUORESCENS RB5

荧光假单胞菌RB5是从土壤中分离得到的一株对禾谷丝核菌有拮抗作用的细菌.通过CAS法检测分析,发现RB5菌株能产生嗜铁素.为明确荧光假单胞菌RB5产嗜铁素的发酵条件,采用摇瓶培养发酵,利用特异光谱吸收法,研究了不同培养条件对RB5菌株嗜铁素产量的影响.最终得出RB5产嗜铁素的最佳发酵条件:起始pH 7.0,接种量2%,瓶装量90 mL/250 mL,发酵时间48 h,Fe3+质量浓度为0.8 mg/L.抑菌试验表明,优化发酵条件后的RB5发酵液(OD400值2.35)有很显著的抑菌效果,抑制率达65.28%.

Benzoyl peroxide has strong oxidation ability, and can react with potassium iodide to generate benzoic acid and iodine. Therefore, the rapid test strip can be prepared according to the principle of the color reaction of starch and iodide. A cellulose acetate membrane was used as the color layer, then was soaked in a color reagent mixture solution containing 0.4% gelatinized starch solution, 10% KI and 4% Na2CO3 for 5 minutes, and was dried under vacuum to obtain the test strip. A standard colourimetric card consisted of ten color blocks, and could show significant color order in the range of benzoyl peroxide 0 to 228 mg/L. The lowest detection limit of benzoyl peroxide in the flour was 36 mg/kg, and the relative error was 11.76% to 16.89%.