AUTHOR=Huang JinLan , Jiang DaiHua , Wang MingShi , Huang XueJiao 

TITLE=Highly Selenite-Tolerant Strain Proteus mirabilis QZB-2 Rapidly Reduces Selenite to Selenium Nanoparticles in the Cell Membrane

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.862130

DOI=10.3389/fmicb.2022.862130

ISSN=1664-302X

ABSTRACT=<p>The application of biosynthesized nano-selenium fertilizers to crops can improve their nutrient levels by increasing their selenium content. However, microorganisms with a high selenite tolerance and rapid reduction rate accompanied with the production of selenium nanoparticles (SeNPs) at the same time have seldom been reported. In this study, a bacterial strain showing high selenite resistance (up to 300 mM) was isolated from a lateritic red soil and identified as <italic>Proteus mirabilis</italic> QZB-2. This strain reduced nearly 100% of 1.0 and 2.0 mM selenite within 12 and 18 h, respectively, to produce SeNPs. QZB-2 isolate reduced SeO<sub>3</sub><sup>2</sup><italic><sup>–</sup></italic> to Se<sup>0</sup> in the cell membrane with NADPH or NADH as electron donors. Se<sup>0</sup> was then released outside of the cell, where it formed spherical SeNPs with an average hydrodynamic diameter of 152.0 ± 10.2 nm. <italic>P. mirabilis</italic> QZB-2 could be used for SeNPs synthesis owing to its simultaneously high SeO<sub>3</sub><sup>2</sup><italic><sup>–</sup></italic> tolerance and rapid reduction rate.</p>