Functional analysis of the ocnE gene involved in nicotine-degradation pathways in Ochrobactrum intermedium SCUEC4 and its enzymatic properties

Abstract

Ochrobactrum intermedium strain SCUEC4 is a newly isolated nicotine-degrading bacterium and can use the nicotine as the sole carbon source via a series of enzymatic catalytic processes. Mechanisms underlying nicotine degradation in this bacterium and the corresponding functional genes remain unclear. Here, we analyzed the function and biological properties of the ocnE gene involved in nicotine degradation pathways in strain SCUEC4. The ocnE gene was cloned by PCR with total DNA of strain SCUEC4, and used to construct the recombinant plasmid pET28a-ocnE. The overexpression of OcnE protein was detected by SDS-PAGE analysis, and functional insight of this protein was spectrophotometrically carried out with monitoring the changes of 2, 5-dihydroxypyridine. Moreover, effects of temperature, pH and metal ions on the biological activities of OcnE protein were analyzed. The results demonstrated that optimal conditions for the biological activities of OcnE, approximate 37.6 kDa, was determined as 25°C, pH 7.0 and 25 μM Fe2+, and the suitable storage conditions for OcnE protein was determined as 0°C and pH 7.0. Conclusively, the ocnE gene owns the ability of 2, 5-dihydroxypyridine dioxygenase. These findings will be beneficial in clarifying the mechanisms of nicotine degradation in Ochrobactrum intermedium strain SCUEC4.

Bacillus sp. YC7 from intestines of Lasioderma serricorne degrades nicotine due to nicotine dehydrogenase

“…Additionally, Wang L. et al studied an A. nicotinovorans molybdenum hydroxylase KDH, which plays a signicant role in nicotine degradation (Wang et al 2021 ). The agnH gene in A. tumefaciens strain SCUEC1 and the ocnE gene in O. intermedium SCUEC4 involved in nicotine-degradation pathways, have also been investigated (Xia et al 2020 ; Yu et al 2021 ). Notably, the nicotine-degrading enzyme, NicA2, has demonstrated its potential in reducing nicotine levels in the blood, nicotine distribution in the brain, and nicotine discrimination and reinforcement in rats (Pentel et al 2018 ).…”

“…With the increasing recognition of the adverse effects of nicotine on human health and the environment, the exploration of microbial degradation pathways, especially in tobacco beetles’ intestinal flora, has become a new and exciting research focus (Huang et al 2020 ; Mu et al 2020 ; Xia et al 2020 ; Yu et al 2021 ; Zhang et al 2022 ). Harnessing the natural biodegradation capabilities of these microorganisms holds the promise of offering a greener and more efficient approach to tackle nicotine pollution.…”

Isolation, Identification and Use of Bacterial Strain Ochrobactrum intermedium PDB-3 for Degradation of the Pesticide Chlorpyrifos

“…Based on recent genome comparison studies, the genus Ochrobactrum was reclassified and its species included in the genus Brucella [42,43]. O. intermedium degrades many pollutants [44], including pesticides [45,46]. For example, O. intermedium SP9 degraded the pesticide cypermethrin to 69.1% within 8 days [47].…”

Insights into Pharmacological Activities of Nicotine and 6-Hydroxy-L-nicotine, a Bacterial Nicotine Derivative: A Systematic Review

“…It is hence no surprise that this ecological niche was occupied by microorganisms that have evolved genes and pathways to utilize this compound to sustain cell growth. Bacteria that have evolved NIC degradation pathways include strains of Paenarthrobacter [103,104], Arthrobacter [105][106][107], Pseudomonas [108][109][110][111][112][113][114][115][116][117], Agrobacterium [118,119], Nocardioides [120,121], Ochrobactrum [122][123][124], Shinella [125,126], Acinetobacter [127,128], Bacillus [129,130], Sphingomonas [131,132], Pusillimonas [133], Rhodococus [121,134,135], and Ensifer [15,136].…”