High-Efficiency Reducing Strain for Producing Selenium Nanoparticles Isolated from Marine Sediment

Abstract

Selenium nanoparticles (SeNPs) are all important for research because they exhibit a higher degree of absorption and lower toxicity than that of their organic and inorganic forms. At present, there are few reports on marine strains that can reduce Se(IV) to generate Se(0). In this study, a strain that reduces sodium selenite to SeNPs with high efficiency was screened from 40 marine strains. The SeNPs-S produced by the whole cells and SeNPs-E produced by the extracellular extract were characterized by FTIR, UV, Raman, XRD and SEM. Based on the results, the two kinds of SeNPs exhibited obvious differences in morphology, and their surfaces were capped with different biomacromolecules. Due to the difference in shape and surface coating, opposite results were obtained for the antibacterial activity of SeNPs-S and SeNPs-E against Gram-positive and Gram-negative bacteria. Both SeNPs-S and SeNPs-E exhibited no obvious cytotoxicity at concentrations up to 100 μg/mL, but SeNPs-E retained lower cytotoxicity when its concentration increased to 200 μg/mL. This is the first report on the detailed difference between the SeNPs produced by whole cells and cell extracts.

A Review of the Antibacterial, Fungicidal and Antiviral Properties of Selenium Nanoparticles

“…This approach is also based on the reduction of selenium-containing precursors to Se 0 . The essential difference between the first and the second type is that biogenic synthesis uses cellular structures [115,131,[146][147][148][149] and bioorganic synthesis uses noncellular extracts of plant and microbial origin to synthesize nanoparticles [117,132,[150][151][152][153]. In this case, reducing agents are usually secondary metabolites, such as flavonoids, thiamine and capsaicin, as well as other agents containing amino groups, extracted from various plants: Spirulina platensis, Azadirachta indica, Trigonella foenum-graecum, Allium sativum, etc.…”

“…SeNPs have been described as having their own antimicrobial properties [112][113][114]. In addition, modified SeNPs with antimicrobial properties can be obtained by biosynthesis, which significantly reduces the cost of their production [115][116][117].…”