Application Maldi-tof Ms Detection And Identification Of Common Probiotics Research

The screening and identifying methods of the candidate probiotic strains, as an important research part of probiotic industry, has been paid great concerns by researchers. In recent years, Matrix-assisted laser desorption ionization time of flight mass spectrometry, which was applied to screen and identify strains based on protein fingerprints of strains, is widely researched because of its characteristics of accuracy, rapidity and high-throughput.In this research, the optimal protocol of detecting and identifying common probiotic strains was firstly established by investigated the influencing factors of identification process, which includes different analytic methods, different matrix substances, different matrix solvents, different solvents of treating sample, different spotting methods and ratios,etc. It also proved that the identification results of Matrix-assisted laser desorption ionization time of flight mass spectrometry possessed highly stability and excellent repeatability. When colonies exceed 104 cfu, experimental strains can be identified to species level by Matrix-assisted laser desorption ionization time of flight mass spectrometry.In addition, to investigate the applicability of Matrix-assisted laser desorption ionization time of flight mass spectrometry, conventional phenotypic identification methods and 16S rDNA sequence homology analysis were used as the control methods. The results demonstrate that Matrix-assisted laser desorption ionization time of flight mass spectrometry was accurate, rapid, simply, inexpensive and can high-throughput identify strains to the genus, species, subspecies and even strain level. Finally, good application prospect of the method was showed in probiotic industry.