Evidence for the role of zinc on the performance of dibenzothiophene desulfurization by Gordonia alkanivorans strain 1B

Abstract

Gordonia alkanivorans strain 1B is able to desulfurize dibenzothiophene (DBT) to 2-hydroxybiphenyl (2-HBP), the final product of the 4S pathway. However, both the cell growth and the rate of desulfurization can be largely affected by the nutrient composition of the growth medium due to cofactor requirements of many enzymes involved in the biochemical pathways. In this work, the effect of several metal ions on the growth and DBT desulfurization by G. alkanivorans was studied. From all the metal ions tested, only the absence of zinc significantly affected the cell growth and the desulfurization rate. By increasing the concentration of Zn from 1 to 10 mg L(-1), 2-HBP productivity was improved by 26%. The absence of Zn(2+), when sulfate was also used as the only sulfur source, did not cause any difference in the bacterial growth. Resting cells grown in the presence of Zn(2+) exhibited a 2-HBP specific productivity of 2.29 micromol g(-1) (DCW) h(-1), 7.6-fold higher than the specific productivity obtained by resting cells grown in the absence of Zn(2+) (0.30 micromol g(-1) (DCW) h(-1)). These data suggests that zinc might have a key physiological role in the metabolism of DBT desulfurization.

Crystal structure of dibenzothiophene sulfone monooxygenase BdsA from Bacillus subtilis WU‐S2B

“…The 4S pathway was first discovered in Rhodococcus erythropolis IGTS8 3 and has also been found in other bacteria. [4][5][6][7] In the 4S pathway of R. erythropolis, three enzymes have been found to be involved in the desulfurization of DBT. 8,9 First, DBT is oxidized to DBT sulfone via DBT sulfoxide by the DBT monooxygenase DszC.…”

“…There are two major pathways, the Kodama pathway and the 4S pathway, for DBT desulfurization. The 4S pathway was first discovered in Rhodococcus erythropolis IGTS8 and has also been found in other bacteria . In the 4S pathway of R. erythropolis , three enzymes have been found to be involved in the desulfurization of DBT .…”

DBT desulfurization by decorating Rhodococcus erythropolis IGTS8 using magnetic Fe3O4 nanoparticles in a bioreactor

“…Molecules with alkyl groups adjoined to the sulfur atom are often used as model molecules in deep HDS studies because these molecules are very difficult to desulfurize. However, HDS is problematic for the treatment of fossil fuels because it is carried out at temperatures and pressures that are so extreme that it will also damage the valuable hydrocarbons and because HDS units are expensive to build and control .…”

On the road to cost-effective fossil fuel desulfurization byGordonia alkanivoransstrain 1B

“…This can be due to an alteration on essential enzymes structure, which need the nutrients supplied in the TES to function properly. 24,25 Since 25% TES (F#10) was the lowest concentration tested that allowed maximum cell growth and in addition it has stimulated desulfurization, this was the chosen amount as the most appropriated to be further tested as minimal TES within a SFM minimized medium.…”