Opposite Enantioselectivities of Two Phenotypically and Genotypically Similar Strains of Pseudomonas frederiksbergensis in Bacterial Whole-Cell Sulfoxidation

Abstract

Soil samples were screened to select microorganisms with the capability to oxidize organic sulfides into the corresponding sulfoxides with differential enantioselectivities. Several bacterial strains that preferentially produced the S-configured sulfoxide enantiomer were isolated. Surprisingly, one bacterial strain, genotypically and phenotypically characterized as Pseudomonas frederiksbergensis, selectively gave the R enantiomer. The finding that two apparently identical organisms displayed opposite enantioselectivities is novel for nongenetically modified organisms.

Enhanced carbon, nitrogen and phosphorus removal from domestic wastewater in a novel anoxic-aerobic photobioreactor coupled with biogas upgrading

“…The DGGE sequencing analysis revealed the presence of the H 2 S degrading strain Pseudomonas frederiksbergensis NR_117177, which supported the biological oxidation of H 2 S in the system (Supplementary material Table S1) [42][43].…”

Enantioselective Synthesis of Sulfoxides: 2000−2009

“…Benzyl methyl sulfide and phenyl isopropyl sulfide were barely consumed by the bacterium. Surprisingly, the stereochemical outcomes for commercially available P. frederiksbergensis DSM 13002 and a strain 33 isolated directly from the soil samples were different: the latter led to R isomers with significantly lower ee (up to 89%) . This observation was explained by the possible difference of the structure of the sulfoxidation enzymes, whose nature, however, was not established.…”

“…Surprisingly, the stereochemical outcomes for commercially available P. frederiksbergensis DSM 13002 and a strain 33 isolated directly from the soil samples were different: the latter led to R isomers with significantly lower ee (up to 89%). 493 This observation was explained by the possible difference of the structure of the sulfoxidation enzymes, whose nature, however, was not established. A new bacterial strain (ECU0066) exhibiting the sulfide monooxygenase activity was isolated from soil samples and identified as Rhodococcus sp.…”

Expanding the toolbox for enantioselective sulfide oxidations: Streptomyces strains as biocatalysts

“…Although their use as biocatalysts in large-scale processes is hampered because of the low stability of the enzymes under reaction conditions and the necessity of expensive cofactors, the utilization of microbial whole-cells might overcome these issues. Hence, several microorganisms have been successfully employed for the asymmetric oxidation of aromatic sulfides, including fungi, bacteria and yeasts (Adam et al, 2005;Pinedo-Rivilla et al, 2007;Mascotti et al, 2012;Elkin et al, 2013). Nevertheless, the discovery of novel wild-type whole-cell biocatalysts capable of performing the oxidation of dialkyl sulfides with high enantioselectivity is still a challenge.…”