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

Abstract

Today, crude oil is an important source of energy and environmental contamination due to the continued use of petroleum products is a matter or urgent concern. In this work, two technological platforms, namely, the use of a robust desulfurizing bacteria and the use of nanotechnology to decorate the surface of the bacteria with nanoparticles (NP), were combined to enhance biodesulfurization (BDS). BDS is an ecologically friendly method for desulfurizing petroleum products while avoiding damage to the hydrocarbons due to the high temperatures normally associated with physical desulfurization methods. First, a bacterium known to be a good organism for desulfurization (Rhodococcus erythropolis IGTS8) was employed in cell culture to remove a recalcitrant sulfur molecule from a common sulfur‐containing compound found in crude petroleum products (dibenzothiophene). 2‐Hydroxybiphenyl (2‐HBP) produced as a consequence of the BDS of dibenzothiophene was determined using Gibbs’ assay. The synthesized NP were characterized by field emission scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction spectroscopy, and vibrating sample magnetometer. The field emission scanning electron microscope and transmission electron microscopy images showed the size of the NP is 7–8 nm. The decorated cells had a long lag phase, but the growth continued until 148 h (at OD600 = 3.408) while the noncoated bacteria grow until 96 h before entering the stationary phase at OD600 = 2.547. Gibbs’ assay results showed that production of 2‐HBP by decorated cells was 0.210 mM at t = 148 h, while 2‐HBP production by nondecorated cells was 0.182 mM at t = 96 h. Finally, the experiments were repeated in a fermenter.

Differential desulfurization of dibenzothiophene by newly identified MTCC strains: Influence of Operon Array

“…Various strains like Rhodococcus erythropolis IGTS8, Rhodococcus sp . Eu-32, Gordonia alkanivorans RIPI 90A, Gordonia alkanivorans 1B, Actinomycete sp ., Gordonia IITR having dsz ABC operon and dsz D genes have been reported for biodesulfurization of DBT and its derivatives in last two decades [ 10 – 15 ]. However, not much attention has been paid to explore the differential biodesulfurization of DBT by bacterial strains with reference to the dsz ABC operon.…”

Microbial Degradation of Rubber: Actinobacteria

“…Actinobacteria strains such as Rhodococcus rhodochrous , Arthrobacter sulfureus , Gordonia rubropertincta , and Rhodococcus erythropolis can also play a role in desulfurizing [ 148 ]. The most common biodesulfurization pathway reported to date is the 4S pathway discovered in Rhodococcus erythropolis IGTS8 [ 149 ].…”

High nitrate removal by starch‐stabilized Fe0 nanoparticles in aqueous solution in a controlled system

“…The results indicating two things: firstly, by increasing nitrate concentration, rate of oxidation of S‐nZVI is decreased, consequently less nitrate is removed. Secondly, it is possible by increasing initial nitrate concentration the amounts of Fe 2+ is reduced to lowest levels and it leads to decrease of nitrate removal efficiency .…”