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Biochemistry Sep 2023Nickel-substituted rubredoxin (NiRd) from has previously been shown to act as both a structural and functional mimic of the [NiFe] hydrogenase. However, improvements...
Nickel-substituted rubredoxin (NiRd) from has previously been shown to act as both a structural and functional mimic of the [NiFe] hydrogenase. However, improvements both in turnover frequency and overpotential are needed to rival the native [NiFe] hydrogenase enzymes. Characterization of a library of NiRd mutants with variations in the secondary coordination sphere suggested that protein dynamics played a substantial role in modulating activity. In this work, rubredoxin scaffolds were selected from diverse organisms to study the effects of distal sequence variation on catalytic activity. It was found that though electrochemical catalytic activity was only slightly impacted across the series, the Rd sequence from a psychrophilic organism exhibited substantially higher levels of solution-phase hydrogen production. Additionally, Eyring analyses suggest that catalytic activation properties relate to the growth temperature of the parent organism, implying that the general correlation between the parent organism environment and catalytic activity often seen in naturally occurring enzymes may also be observed in artificial enzymes. Selecting protein scaffolds from hosts that inhabit diverse environments, particularly low-temperature environments, represents an alternative approach for engineering artificial metalloenzymes.
Topics: Hydrogenase; Rubredoxins; Catalysis; Oxidation-Reduction
PubMed: 37579005
DOI: 10.1021/acs.biochem.3c00249 -
Journal of Hazardous Materials Oct 2023Sulfate-reducing bacteria (SRB) were effective in stabilizing Sb. However, the influence of electron donors and acceptors during SRB remediation, as well as the...
Sulfate-reducing bacteria (SRB) were effective in stabilizing Sb. However, the influence of electron donors and acceptors during SRB remediation, as well as the ecological principles involved, remained unclear. In this study, Desulfovibrio desulfuricans ATCC 7757 was utilized to stabilize soil Sb within microcosm. Humic acid (HA) or sodium sulfate (NaSO) were employed to enhance SRB capacity. The SRB+HA treatment exhibited the highest Sb stabilization rate, achieving 58.40%. Bacterial community analysis revealed that SRB altered soil bacterial diversity, community composition, and assembly processes, with homogeneous selection as the predominant assembly processes. When HA and NaSO significantly modified the stimulated microbial community succession trajectories, shaped the taxonomic composition and interactions of the bacterial community, they showed converse effect in shaping bacterial community which were both helpful for promoting dissimilatory sulfate reduction. NaSO facilitated SRB-mediated anaerobic reduction and promoted interactions between SRB and bacteria involved in nitrogen and sulfur cycling. The HA stimulated electron generation and storage, and enhanced the interactions between SRB and bacteria possessing heavy metal tolerance or carbohydrate degradation capabilities.
Topics: Antimony; Oxidation-Reduction; Soil; Biological Availability; Desulfovibrio; Bacteria; Sulfates
PubMed: 37567138
DOI: 10.1016/j.jhazmat.2023.132256 -
Journal of Hazardous Materials Oct 2023This paper describes a unique molecular mechanism for the EPS-mediated synthesis of CdS QDs by sulfate-reducing bacteria (SRB) under carbon source-induced reinforcement....
This paper describes a unique molecular mechanism for the EPS-mediated synthesis of CdS QDs by sulfate-reducing bacteria (SRB) under carbon source-induced reinforcement. Under the induced by carbon sources (HCOONa, CHCOONa and CHO), there was a significant increase in EPS production of SRB, particularly in protein, and the capacity of Cd(II) adsorption was further enhanced. CdS QDs were extracellularly synthesized by adding S after Cd(II) adsorption. The results showed that CdS QDs were wrapped or adhered by EPS, and the most significant increase in Arg and Lys among basic amino acids in EPS after HCOONa-induced was 133.34% and 63.89%, respectively. This may serve as a biological template for QD synthesis, producing protein gels with a large number of microcavities and controlling the nucleation of CdS QDs. The highest yield of HCOONa-CdS was achieved after induction, with 23.59 g/g biomass per unit strain, which was 447.34% higher than that before induction and was at a high level in previous studies. The synthesized CdS QDs were uniform in size distribution and had higher luminescence activity and a larger specific surface area than those synthesized by the chemical synthesis route, provides a new idea for EPS treatment of heavy metal wastewater and metal biorecovery.
Topics: Cadmium; Desulfovibrio desulfuricans; Carbon; Metals, Heavy; Desulfovibrio
PubMed: 37499495
DOI: 10.1016/j.jhazmat.2023.132146 -
Emerging Infectious Diseases Aug 2023An 84-year-old man in Japan who had undergone endovascular aortic repair 9 years earlier had an infected aneurysm develop. We detected Desulfovibrio desulfuricans MB at...
An 84-year-old man in Japan who had undergone endovascular aortic repair 9 years earlier had an infected aneurysm develop. We detected Desulfovibrio desulfuricans MB at the site. The patient recovered after surgical debridement, artificial vessel replacement, and appropriate antimicrobial therapy. Clinicians should suspect Desulfovibrio spp. infection in similar cases.
Topics: Male; Humans; Aged, 80 and over; Desulfovibrio desulfuricans; Aneurysm; Japan
PubMed: 37486321
DOI: 10.3201/eid2908.230403 -
Bioelectrochemistry (Amsterdam,... Oct 2023Effect of exogenous riboflavin on sulfate-reducing bacteria (SRB) corrosion of a spirally welded joint (WJ) of X80 steel was investigated by SEM/EDS, XPS, 3D ultra-depth...
Effect of exogenous riboflavin on sulfate-reducing bacteria (SRB) corrosion of a spirally welded joint (WJ) of X80 steel was investigated by SEM/EDS, XPS, 3D ultra-depth microscopy and electrochemical measurements. The main style of SRB corrosion of the WJ is local corrosion. The local corrosion sensitivity of the heating affected zone (HAZ) of the WJ was always lower than that of the weld zone (WZ) and base metal (BM) in all the SRB-inoculated mediums. SRB corrosion of the WJ is selective. With the dosage increase of riboflavin, the selective pitting corrosion of the WJ becomes more pronounced.
Topics: Desulfovibrio desulfuricans; Biofilms; Corrosion; Desulfovibrio; Steel; Riboflavin
PubMed: 37235890
DOI: 10.1016/j.bioelechem.2023.108469