适合高产铁载体细菌筛选、检测体系的改进与探析

采用pH6．8的磷酸缓冲液代替通用CAS固体检测培养基中的MM9缓冲体系，不加哌嗪二乙醇磺酸，得到颜色稳定、检测效果明显、配制方便，适合高产铁载体细菌筛选与检测的新型检测平板。根据CAS检测液连续吸收光谱比较分析结果，将CAS液体定量检测体系中的检测波长由630nm改为680nm，可以克服OD630读数偏高、易受干扰的问题，而且OD680与铁载体浓度线性关系不变，但采用OD680检测不同细菌产铁载体能力的差异更为明显，因此提高了CAS定量检测的灵敏度，更适合高产铁载体细菌筛选与检测。

Improvement and Analysis in Over-siderophores Production Bacteria Filtrating and Detecting

A novel stable blue agar plate which is convenient to preparing and more effective than the universal chrome azurol sulfonate (CAS) assay established by Schwyn and Neilands was designed by replacing MM9 growth medium and pipes with certain concentrate of phosphorus buffer solution which pH could be stabled at 6.8. It is more suitable for screening over- siderophores production bacteria. Since OD_ 630 of the sample is usually out of the range of spectrophotometer with CAS assay solution when quantifying the siderophores and the outcome is not steady,the measuring wavelength had been changed to 680 nm corresponding to the middle of max absorbance and the correlation between siderophores concentrations and OD was unchanged. But the detecting sensitivity is elevated by enlarged the absorbance differences among samples with different productivity of siderophores at 680 nm .