Spatiotemporal distribution of chemical signatures exhibited by Myxococcus xanthus in response to metabolic conditions

• Published in: Analytical and bioanalytical chemistry Vol. 414; no. 4; pp. 1691 - 1698
• Main Authors: Do, Hyein, Madukoma, Chinedu S., Sundaresan, Vignesh, Shrout, Joshua D., Hoffman, Anthony J., Bohn, Paul W.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.02.2022; Springer; Springer Nature B.V
• Subjects: Analytical Chemistry; Availability; Biochemistry; Cell Culture Techniques; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Culture Media - chemistry; Culture Media - metabolism; Environmental conditions; Food Science; Fruit bodies; Identification and classification; Laboratory Medicine; Life cycles; Lycopene; Metabolism; Metabolites; Metabolome; Methods; Monitoring/Environmental Analysis; Myxobacterales; Myxococcus xanthus; Myxococcus xanthus - chemistry; Myxococcus xanthus - growth & development; Myxococcus xanthus - metabolism; Nutrient availability; Principal components analysis; Properties; Raman spectroscopy; Research Paper; Secondary metabolites; Soil bacteria; Soil microorganisms; Spatial analysis (Statistics); Spatial distribution; Spectral signatures; Spectrum Analysis, Raman; Temporal distribution; United States; Confocal Raman; Nutrients; Fruiting bodies; Metabolism; Myxococcus xanthus
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-021-03795-6

Myxococcus xanthus is a common soil bacterium with a complex life cycle, which is known for production of secondary metabolites. However, little is known about the effects of nutrient availability on M. xanthus metabolite production. In this study, we utilize confocal Raman microscopy (CRM) to examine the spatiotemporal distribution of chemical signatures secreted by M. xanthus and their response to varied nutrient availability. Ten distinct spectral features are observed by CRM from M. xanthus grown on nutrient-rich medium. However, when M. xanthus is constrained to grow under nutrient-limited conditions, by starving it of casitone, it develops fruiting bodies, and the accompanying Raman microspectra are dramatically altered. The reduced metabolic state engendered by the absence of casitone in the medium is associated with reduced, or completely eliminated, features at 1140 cm −1 , 1560 cm −1 , and 1648 cm −1 . In their place, a feature at 1537 cm −1 is observed, this feature being tentatively assigned to a transitional phase important for cellular adaptation to varying environmental conditions. In addition, correlating principal component analysis heat maps with optical images illustrates how fruiting bodies in the center co-exist with motile cells at the colony edge. While the metabolites responsible for these Raman features are not completely identified, three M. xanthus peaks at 1004, 1151, and 1510 cm −1 are consistent with the production of lycopene. Thus, a combination of CRM imaging and PCA enables the spatial mapping of spectral signatures of secreted factors from M. xanthus and their correlation with metabolic conditions. Graphical abstract