Identification by MALDI-TOF MS of Environmental Bacteria with High Potential to Degrade Pyrene

An alternative to remove polycyclic aromatic hydrocarbons (PAHs) of the environment is using hydrocarbonoclastic bacteria. The aim of this work was to study the bacterial diversity of indigenous isolates with potential to degrade pyrene. We used MALDI-Biotyper (Bruker Daltonics) as a powerful analytical tool for identification. Bacteria were isolated from surface seawater and marine sediments samples of three sites from the coast of Rosarito Port, B.C., Mexico. Total concentration of PAHs in collected samples was quantified by GC-MS, showed values ranged 0.461-0.525 ng mL-1 and of 74 -266 ng g-1 in seawater and sediments samples, respectively. A total of 52 bacteria with capacity to grow in 25 mg L-1 pyrene as sole carbon and energy source were taxonomically identified and classified by MALDI-Biotyper system by comparing the mass spectra with library and/or to use chemometric tools as Principal Components Analysis (PCA) and Composite Correlation Index (CCI) to evaluate possible differences to isolate level. The identified isolates were represented by three phylogenetic groups: Firmicutes, Actinobacteria and Proteobacteria. Of these isolates, Kocuria strains appear to be excellent candidates to continue PAHs degradation studies.