Estudo do potencial biotecnológico de pigmentos extraídos de bactérias isoladas de ambientes da caatinga e costeiro (Ceará, Brasil)

Abstract

Pigments are substances which absorb the light on visible spectrum in one or more wavelengths. In bacterial cells, pigments confer a protective effect against ultraviolet radiation (UV) damages. This characteristic confer to pigments an alternative to substitute photoprotective substances used in cosmetic products which show environmental toxic effects. Among the pigments produced, the carotenoids confer to bacterial cell colors since yellow to deep red. However, there is little information about diversity and biotechnological potential of bacterial pigments. Thus, the aim of this research was to evaluate the potential of photoprotective effect of pigments extracted of bacterial strains isolated from caatinga biome and coastal zone of state of Ceará. In order to achieve this goal, nineteen bacterial strains were selected from bacterial collection of Fish and Environmental Microbiology Lab (LAMAP). Strains were inoculated on Tryptic Soy Agar (TSA) added by glicerol 3% e incubated at 35°C for 24 h to verify the pigment formation. Among the chosen strains, Gram -negative bacterial (63%) were more identified than Gram-positive bacteria (37%).When strains were exposed to ultraviolet radiation for different times, 15,8% of these strains showed growth capacity for 15 minutes of UV exposition. The pigments were extracted using the organic solvent method (Acetone / Ethyl Acetate) and then used to test antimicrobial activity using bacterial indicator strains: E. coli (ATCC25922), Pseudomonas sp. (ATCC27853), S. aureus (ATCC25923). There was no bacterial growth inhibitory activity by pigments against the bacterial indicators. Photoprotective effect on a third non-pigment-producing bacterium (E. coli) was also tested. Most pigments were able to protect E. coli against UV radiation damages. This research is an initial step in the knowledge of the biotechnological potential of bacterial pigments originating in the northeastern region characterized by high insolation index. This knowledge contributes to the development of new photoprotective technologies and products with less adverse effects on the environment.