UC San Diego

Previously, scientist studied metabolites of polymicrobial communities by direct chemical extraction or microbial isolation. While the old day method does not provide a lot of information from a polymicrobial community, in this master thesis, I have introduced and shown a novel method to investigate the metabolites and the metabolites distribution in three-dimensional space on a polymicrobial community by guidance of advanced technique of mass spectrometry such as MALDI-IMS & LC-MS. Specifically, I have developed a methodology to construct a three- dimensional metabolites map of a Peltigera sp. lichen to reveal the spatial metabolites distribution on lichen, hypothesis the possible function of a specific metabolites in the community and identify some of the specific metabolites. As a consequence of this new 3D metabolites map methodology, wide ranges of molecules were observed in this Peltigera sp. 3D model such as polypeptides, single amino acid, photosensitive molecules, polysaccharide and some lipid molecules. In addition, the 3D model clearly shows that the metabolites distribution inside Peltigera sp. lichen, and distributions of chlorophylls as well as a lipid from lichen fungi are correlated with previous reported literature. Some of these molecules are able to identify and derive its function in this biological system. These results demonstrated that the 3D metabolites map of Peltigera sp. lichen provides a means to direct visualize the spatial architecture of metabolites inside this polymicrobial community as well as study them from different angle, and hence useful for studying the metabolites and biological system of polymicrobial communities