Analysis Of Antibiotics In Pseudomonas: Determination Of Phenazines And Residue Analysis Of Pyoluteorin

Pseudomonads produce Pyoluteorin (Plt) and phenazine pigments, including PCA, PYO and 1-OH-PHZ. A rapid and accurate method with high sensitivites to separate and determinate these substances is still lacking, which will be of great help in the study of their dynamic biosynthesis.In this paper, a reversed phase HPLC mehod was developed to separate and determinate PCA, PYO, 1-OH-PHZ and Plt from fermentation liquor of Pseudomonas species, which will be important to the further study on the biosynthesis mechanism of current phenazines and the determination of new ones. The LOD and the largest migration time of PCA, PYO, 1-OH-PHZ and Plt were 06.347 ng.mL^-1, 78.74 ng.mL^-1, 9.173 ng.mL^-1, 17.2 ng.mL^-1, and 7.788 min, 8.227 min, 12.045 min and 11.515 min.As potential biological pesticides, PCA and Plt have strong inhibitory activity against agricultural pests, including bacteria, epiphytes, and weeds. However, pesticide residue after being incorporated into the environment may become a potential threat to human health and the ecological system. The residue analysis of PCA in the soil has been studied. Therefore, a rapid and accurate method to determine Plt residue in soil has to be developed in order to use it as a fungicide without harming the environment.Using Soxhlet extraction and ultrasonic extraction, a high efficiency recovery method was set up to extract Plt from soil. The recoveries of Plt at spiking levels from 0.05 to 0.50 mg.kg^-1 were 78.25% to 94.18%. We developed a method of capillary electrophoresis combined with field-amplified sample stacking to determine Plt. The LOD of Plt was 0.107μg.mL^-1, and the migration time of Plt was 6.3 min. Based on the optimized method, the degradation curve of Plt in soil was studied. Plt was proved with comparatively high decomposition rate and good biological safety.