Biological nano-mineralization of Ce phosphate by Saccharomyces cerevisiae

Crystal Chemistry and Stability of Hydrated Rare-Earth Phosphates Formed at Room Temperature

“…In these studies, biogenic Ce phosphate was characterized as having a needle-shaped rhabdophane structure [20], while Yb phosphate precipitated as amorphous nanoparticles~50 nm in size [21]. The structure and morphology of these phases are very similar to those of LREPO 4,hyd and HREPO 4,hyd observed in the present study.…”

“…Previous studies highlighted the importance of biomineralization of RE phosphates in constraining the mobility of REEs in the environment [20,21,67]. In these studies, biogenic Ce phosphate was characterized as having a needle-shaped rhabdophane structure [20], while Yb phosphate precipitated as amorphous nanoparticles~50 nm in size [21].…”

Biorecycling of Precious Metals and Rare Earth Elements

“…Hence a phytic acid-based column system may have three K m values and be more difficult to describe mathematically, but this represents a potentially attractive route for potential metal recovery from wastes. A recent study (Jiang et al, 2010) has shown another route to REE biomineralisation. This used the yeast Saccharomyces cerevisiae and Ce(III).…”

“…(Ce(III)/(IV) is a surrogate for Pu(III)/IV) and Np(III)/(IV), and a comprehensive suite of analytical methods, including synchrotronbased X-ray absorption fine structure (XAFS), showed conclusively that Ce(III) was deposited on the yeast cell surface as needle-shaped Ce(III) phosphate nanocrystals with a monazite structure. Importantly, no exogenous phosphate was added and the mobilisation of intracellular phosphate reserves to supply inorganic phosphate into the growing crystals was concluded (Jiang et al, 2010). Since yeast is well known to store phosphate in the form of polyphosphate (which is known to support metal desolubilisation when mobilised: see earlier) it seems likely that the yeast phosphate was derived from this source, with metal phosphate deposition via polyP mobilisation and phosphate efflux processes.…”

“…Since yeast is well known to store phosphate in the form of polyphosphate (which is known to support metal desolubilisation when mobilised: see earlier) it seems likely that the yeast phosphate was derived from this source, with metal phosphate deposition via polyP mobilisation and phosphate efflux processes. The yeast system of Jiang et al, (2010), unlike Acinetobacter spp, (Boswell et al, 2001) needs no aerobic/anaerobic cycling and is thus intrinsically a more useful process for industrial REE recovery but the limit of metal deposition needs to be established. Importantly, and as also found for the bacterial system with UO 2 2+ at pH 4 , removal of Ce(III) (0.18 mM) by the yeast was initially negligible (up to 96 h at pH 3) and then proceeded abruptly to 60% of the initial concentration after 120 h. Phosphate was produced by the cells at pH 3, again indicating that metal phosphate solubility and not biochemical activity, is the limiting factor in biomineral formation at low pH.…”