Recording date:

Duration:
00:32:36

Speaker:
Prof. Dr. Dimitris G. Hatzinikοlaou, Department of Biology, National and Kapodistrian University of Athens (NKUA), Athens, Greece

Abstract:

Synthetic biology and metabolic engineering have emerged as powerful enabling platforms for industrial biotechnology. Aerobic biodesulfurization (BDS) of fossil fuels via the 4S pathway serves as a compelling paradigm of this transformation.  ecalcitrant organosulfur compounds in mid-distillate fuels resist conventional hydrodesulfurization (HDS), yet biological C–S bond cleavage can selectively remove sulfur while preserving the hydrocarbon backbone. Recent work with the model  iocatalyst Rhodococcus qingshengii IGTS8, has elucidated the interplay between sulfur assimilation and the desulfurization phenotype, revealing a critical regulatory role of the reverse transsulfuration enzymes and demonstrating that medium  omposition can overturn the widely accepted sulfate-dependent repression. Precise genome editing enabled an in locus combinatorial strategy comprising operon rearrangement, promoter exchange, and gene-overlap removal, yielding stable,  on-repressible biocatalysts with markedly elevated BDS activities. Targeted chromosomal reinsertion of the flavin reductase dszD further boosted desulfurization by alleviating cofactor limitation. Translating these insights to Gram-negative  costs, a rationally designed Pseudomonas putida chassis carrying a refactored dsz operon demonstrated high desulfurization efficiency. Process-level studies in bubble-column bioreactors and optimized fed-batch cultivation complete the picture  rom gene to reactor, illustrating how synthetic and metabolic engineering can revitalize bioprocesses previously stalled between laboratory promise and industrial deployment.