Sorting oleaginous yeast by using optical manipulation and Raman spectroscopy

Extensive research has been carried out in an effort to screen the oleaginous microorganisms. Here, Raman spectroscopy and laser tweezers were used to sort oleaginous yeast from mixed yeast cells. The preprocessing of subtracted background, 17 points S-G smoothing filter, polynomial fitting baseline correction and vector normalization were performed and the main features information of intracellular substances from the Raman spectroscopy of yeast cells was extracted by combining principal component analysis. Based on the distinguished composition of oleaginous yeast and non-oleaginous different yeast, a sorting model was established. The test yeast cell in optical trapping was distinguished real-time by the model referring to its Raman spectra. The cells distinguished as oleaginous yeast were collected by means of optical manipulation. The sorted oleaginous yeast cells were verified by microbial culture and Sudan black B test. The result illustrates that Raman spectroscopy combined with optical manipulation is an effective technique for sorting oleaginous yeast and other economic microorganisms.