Structural and spectral features of selenium nanospheres produced by Se-respiring bacteria

Abstract

Certain anaerobic bacteria respire toxic selenium oxyanions and in doing so produce extracellular accumulations of elemental selenium [Se(0)]. We examined three physiologically and phylogenetically diverse species of selenate-and selenite-respiring bacteria, Sulfurospirillum barnesii, Bacillus selenitireducens, and Selenihalanaerobacter shriftii, for the occurrence of this phenomenon. When grown with selenium oxyanions as the electron acceptor, all of these organisms formed extracellular granules consisting of stable, uniform nanospheres (diameter, ϳ300 nm) of Se (0)

Selenium environmental cycling and bioavailability: a structural chemist point of view

“…Some bacteria, like Enterobacter cloacae SLD1a-1, have known pathways for the detoxification of selenate which include a series of reductive transformations of the anion and in the presence of an electron donor (Watts et al 2003). Several bacteria strains have been identified to reduce toxic selenium oxyanions using lactate as electron donor, and producing elemental selenium nanospheres that accumulated inside and outside the cell wall (Oremland et al 2004). This process has been observed even at very low selenium concentrations (lM) (Lenz et al 2008a).…”

Aerobic microbial manufacture of nanoscale selenium: exploiting nature’s bio-nanomineralization potential

“…A variety of microorganisms, bacteria, yeast, fungi and algae, can adsorb and accumulate metals but only a few groups can selectively reduce metal ions to produce nano-scale mineral phases (Oremland et al 2004). These organisms have the unique ability to produce inorganic phases of constant chemical composition and size (Cui and Gao 2003;Pearce et al 2008).…”

Bacillus cereus, selenite-reducing bacterium from contaminated lake of an industrial area: a renewable nanofactory for the synthesis of selenium nanoparticles

“…It is significant to note that, in the literature, selenium nanoparticle producing bacteria are reported in wide range of environments under aerobic and anaerobic conditions including in sludge and sewerage (Mishra et al 2011). The anaerobic/anoxic bacteria include strains such as Selenihalanaerobacter shriftii DSSE1, Sulfurospirillum barnesii (Oremland et al 2004), Rhodopseudomonas palustris N (Li et al 2014), Veillonella atypica (Pearce et al 2008), Shewanella putrefaciens 200 (Jiang et al 2012), Shewanella sp. HN-41 (Lee et al 2007), etc.…”

“…Thus, the selenium nanoparticle synthesis is attributed to bacterial reduction of selenite only. It is reported in the literature that the biogenic selenium nanoparticles exhibit different spectroscopic characteristics in comparison with chemogenic selenium nanoparticles due to unique internal structural arrangements of the selenium atoms (Oremland et al 2004). Thus, the bacterial strain used in the current study can be utilized as a nanofactory for large-scale commercial production of selenium nanoparticles.…”

“…Selenite-reducing bacteria have been isolated from a variety of environments including Mono Lake of California (Oremland et al 2004), Dead sea, a salt lake (Oremland et al 2004), Caspian sea of Iran (Shakibaie et al 2015), sediments of Cama-rones river from Atacama desert, Northern Chile (Torres et al 2012), activated sludge (Srivastava and Mukhopadhyay 2013), sludge of Taiyuan sewage plant, China (Li et al 2014), drainage slough from Nevada (Oremland et al 2004), and anaerobic granules from paper mill wastewater treating reactor (Jain et al 2015). In addition, from the soil of a antimony mine from Lengshuijiang, southern China (Zheng et al 2014), soil of a magnesite mine from Salem, India (Ramya et al 2015), soil of a coal mine from West Bengal, India (Dhanjal and Cameotra 2010), selenium laden agricultural soil of North-East Punjab, India (Bajaj et al 2012), soil of mangrove forest from Bhitarkanika, Orissa, India (Mishra et al 2011), rhizosphere soil of a selenium hyperaccumulator legume grown in seleniferous mine from Sardina, Italy (Lampis et al 2014), rhizosphere of wheat grown in herbicide contaminated soil (Dwivedi et al 2013), and rhizosphere of cereal plants grown in ash-derived volcanic soil of southern Chile (Durán et al 2015).…”