Biotransformation of Oleanolic Acid Using Rhodococcus rhodochrous IEGM 757

Abstract

Using the bioresources of the Regional Specialised Collection of Alkanotrophic Microorganisms (acronym IEGM, Perm, Russia; WFCC # 285), R. rhodochrous IEGM 757 was selected, which catalyzed the C5, C22, and C23 functionalization of pentacyclic triterpenoid oleanolic acid (OA, 3β-hydroxyolean-12-en-28-oic acid, 1.0 g/L) to form a new 5α,22α-dihydroxy derivative of gypsogenic acid (3β,5α,22α-trihydroxyolean-12-ene-23,28-dioic acid) for 5 days. In silico analysis showed that, compared to the native triterpenoid, the OA metabolite may be more soluble in water and less ecotoxic, act as an apoptosis agonist and insulin promoter, and have chemopreventive and analgesic effects. Phase-contrast, fluorescent, scanning, and transmission electron microscopy and X-ray spectroscopy demonstrated the high resistance of R. rhodochrous IEGM 757 to OA. This creates opportunities for further research and development of a method for the production of the OA metabolite. New-generation sequencing of the R. rhodochrous IEGM 757 whole genome, annotation and bioinformatics analysis of the obtained sequences, and real-time PCR were applied. As a result, 24 genes encoding CYP450 enzymes were found, which are highly likely to be involved in the process of OA oxidation.

Phenotypic and metabolic adaptations of Rhodococcus cerastii strain IEGM 1243 to separate and combined effects of diclofenac and ibuprofen

“…These structures appeared as loop-like formations and are believed to be primarily involved in the transportation of complex compounds and their subsequent degradation through the action of membrane-bound enzymes ( Royes et al, 2020 ; Thi Mo et al, 2022 ). Similar structures have been observed in previous studies involving rhodococci grown in the presence of benzoate ( Solyanikova et al, 2017 ), oleanolic acid ( Luchnikova et al, 2022 ), as well as liquid and solid n-hexadecane ( Thi Mo et al, 2022 ). This suggests a common mechanism or adaptive response in the formation of these membrane-like structures across different environmental conditions and compound exposures.…”

“…The staining process allowed for differentiation between live and dead cells. Visualization of the stained cells was carried out using an Axio Imager M2 microscope (Carl Zeiss Microscopy GmbH, Jena, Germany) in fluorescence mode ( Luchnikova et al, 2022 ). Images were captured by an Axoicam 506 Color camera (Carl Zeiss Microscopy GmbH, Jena, Germany) and Zen Blue 3.1 software (Carl Zeiss Microscopy GmbH, Jena, Germany).…”

“…To identify intracellular lipid inclusions, the rhodococci were stained with Nile Red (Nanjing Dulai Biotechnology Co., Nanjing, China) ( Spiekermann et al, 1999 ) with slight modifications ( Luchnikova et al, 2022 ). Briefly, the cell suspension was centrifuged at 12,000 rpm for 5 min to obtain a cell pellet.…”

Rhodococcus rhodochrous IEGM 1360, an Effective Biocatalyst of C3 Oxidative Transformation of Oleanane Triterpenoids

“…Morphometric studies revealed that OA induced a decrease in the cell surface area-to-volume ratio and an increase in the cell wall roughness of resting cells (Table 1) compared to the growing culture (Luchnikova et al, 2021(Luchnikova et al, , 2022). An increase in the degree of roughness of the cell surface may result from the secreted extracellular polymers (see Fig.…”

“…Examples of bacterial transformation of OA and GA are rare and include processes catalyzed by members of the genera Bacillus, Nocardia, and Streptomyces, which exhibit transforming activity at triterpenoid concentrations no more than 0.3 g/L (Ludwig et al, 2015;Xu et al, 2017Xu et al, , 2020. We have previously described a nonpathogenic strain Rhodococcus rhodochrous IEGM 1360 catalyzing the directed transformation of 1.0 g/L OA or GA for 7 days (Luchnikova et al, 2021(Luchnikova et al, , 2022.…”