.......................................................................................................................................... VII RESUMO ................................................................................................................................................ IX LIST OF FIGURES ................................................................................................................................... XII LIST OF TABLES .................................................................................................................................... XIII ABREVIATION LIST .............................................................................................................................. XIV 1 INTRODUCTION ................................................................................................................................. 1 1.1 Sulfur problematic and the need for fossil fuels desulfurization ............................................... 1 1.2 Gordonia alkanivorans strain 1B ............................................................................................... 2 1.3 Carotenoids ............................................................................................................................... 3 1.3.1– Functions and applications .................................................................................................. 3 1.3.2Production ........................................................................................................................... 4 1.3.3Conditions for carotenoids production ................................................................................ 5 1.3.3.1Gordonia genus carotenoids production .................................................................... 6 1.4 Scope of the Thesis .................................................................................................................... 6 2 – MATERIALS AND METHODS ............................................................................................................. 7 2.1 Chemicals and Reagents ............................................................................................................ 7 2.2Microorganism and Culture Media ............................................................................................ 7 2.3Experimental Design Methodology ............................................................................................ 8 2.4 Carotenoids Extraction .............................................................................................................. 8 2.5 Analytical Methods .................................................................................................................... 9 2.5.1 Optical Density and Dry Cell Weight .................................................................................... 9 2.5.2Sugar Consumption Evaluation ............................................................................................. 9 2.5.3Flow Cytometry Analysis for Cell Physiological Evaluation .................................................... 9 2.5.4Pigments Analysis ............................................................................................................... 10 2.6Determination of Antioxidant Activity ...................................................................................... 10 2.7Determination of Antimicrobial Activity ................................................................................... 11 3RESULTS AND DISCUSSION............................................................................................................... 11 IV 3.1Experimental Designs ................................................................................................................ 11 3.1.1 – ED1 (L0) .............................................................................................................................. 12 3.1.2 – ED2 (L400) ........................................................................................................................... 15 3.1.3 – Analysis of ED Factors ....................................................................................................... 18 3.1.4 – Comparison between ED1 and ED2 ................................................................................... 19 3.2 Influence of time ...................................................................................................................... 21 3.2.1 Metabolic parameters ....................................................................................................... 21 3.2.2 Carotenoids analysis .......................................................................................................... 22 3.2.3 Evaluation of cell physiological state by flow cytometry ................................................... 26 3.2.4 Antioxidant activity ............................................................................................................ 27 3.2.5 Antimicrobial activity ......................................................................................................... 28 4 – CONCLUSION .................................................................................................................................. 28 5 – FUTURE WORKS ............................................................................................................................. 30 6 BIBLIOGRAPHY ................................................................................................................................ 30 7 – APPENDIXES ................................................................................................................................... 35