Custom MALDI-TOF Mass Spectrometric Database for identification of environmental Burkholderia and related genera

Success of microbial natural products discovery programs is dependent on quick and concise discrimination between isolates from diverse environments. However, laboratory isolation and identification of priority genera using current 16S rRNA PCR-based methods is both challenging and time-consuming. In clinical settings, MALDI-TOF MS is used to rapidly identify unknown bacterial pathogens, yet this has not been widely adapted for isolation of environmental bacteria. To expedite isolation of Gram-negative proteobacterial order Burkholderiales, we have created a main spectral (MSP) library for the Bruker Biotyper MALDI mass spectrometer that includes 95 entries of Burkholderia, Caballeronia, Paraburkholderia, and other environmentally related genera. We tested the effectiveness of the reference library by analyzing 49 unknown environmental isolate strains before comparing to results of traditional 16S sequencing. The MALDI Biotyper correctly identified all strains to the genus level when sufficient reference spectra were available. This dataset is freely available to the scientific research community for use in taxonomic assignments of environmentally-derived bacteria from the order Burkholderiales.