双波长分光光度法快速测定利用木糖生产普鲁兰多糖发酵液中的多糖产量与残余木糖量

Rapid determination of the contents of Pullulan and Xylose in the fermentation broth from xylose production of pullulan by aureobasidium pullulans through dual-wavelength spectrophotometry

以间苯三酚-浓硫酸为显色剂,建立了双波长分光光度法同时测定利用木糖产普鲁兰多糖发酵液中产物与底物量的方法。显色剂配方为2%的间苯三酚乙醇溶液与浓硫酸1：1（V/V）混合。木糖的测定波长为444 nm和405 nm,普鲁兰多糖的测定波长为420 nm和465 nm。测定条件为1 mL底物,加入5 mL显色剂,沸水浴10 min,冷却至室温,加入10 mL蒸馏水混匀。葡萄糖与木糖浓度在10-300μg/mL浓度范围内线性关系良好。重复性实验得到普鲁兰多糖和木糖的RSD分别为1.6%和2.5%,加标回收实验得到普鲁兰多糖和木糖的回收率分别在92.5%-100.3%和96.9%-103.8%之间,相对标准偏差分别为3.7%和3.5%。说明该方法适用于发酵液中木糖与多糖含量的同时测定。

Using phloroglucinol-sulfuric acid as coloring agent, the amount of polysaccharide and xylose were simuhaneously determined by dual wavelength spectrophotometry. The wavelengths at 444 nm and 405 nm, 420 nm and 465 nm were selected as the measuring wavelength for xylose and Pullulan respectively. The color reagent solution was prepared by dissolving 2 grams of phloroglucinol in 100 mL anhydrous alcohol, followed by mixing with ing 100 mL sulfuric acid. The optimal determination conditions are 1 mL substrates with 5 mL coloring agent,boiling water bath for 10 min,cooling to room temperature, mixing with 10 mL of distilled water. Results show that the concentrations of glucose and xylose in 10 -300 μg/mL obey beer＇s law. The repetitive experiment indicated that the RSD of Pullulan and xylose was 1.6% and 2.5% respectively. Recovery rate of polysaccharide and xylose was 92.5% - 100.3% and 96.9% - 103.8% , and RSDs deviation were 3.7% and 3.5% respectively.