title: Aeration controls the reduction and methylation of tellurium by the aerobic, tellurite-resistant marine yeast Rhodotorula mucilaginosa.
abstract: We previously described a marine, tellurite-resistant strain of the yeast Rhodotorula mucilaginosa that both precipitates intracellular Te0 and volatilizes methylated Te compounds when grown in the presence of the oxyanion tellurite. The uses of microbes as a "green" route for the production of Te0-containing nanostructures and for the remediation of Te-oxyanion wastes have great potential, and so a more thorough understanding of this process is required. Here, Te precipitation and volatilization catalyzed by R. mucilaginosa were examined in continuously aerated and sealed (low oxygen concentration) batch cultures. Continuous aeration was found to strongly promote Te volatilization while inhibiting Te0 precipitation. This differs from the results in sealed batch cultures, for which tellurite reduction to Te0 was found to be very efficient. We show also that volatile Te species may be degraded rapidly in medium and converted to the particulate form by biological activity. Further experiments revealed that Te0 precipitates produced by R. mucilaginosa can be further transformed to volatile and dissolved Te species. However, it was not clearly determined whether Te0 is a required intermediate for Te volatilization. Based on these results, we conclude that low oxygen concentrations will be the most efficient for production of Te0 nanoparticles while limiting the production of toxic volatile Te species, although the production of these compounds may never be completely eliminated.
authors: School of Marine Science and Policy, College of Earth, Ocean, and Environment, University of Delaware, Newark, Delaware 19711, USA.
authors: Patrick R L
authors: PR
authors: Ollivier
authors: Andrew S
authors: AS
authors: Bahrou
authors: Thomas M
authors: TM
authors: Church
authors: Thomas E
authors: TE
authors: Hanson
references: Appl Environ Microbiol. 1977 Jan;33(1):31-7
references: 16345188
references: J Nanosci Nanotechnol. 2006 Mar;6(3):719-25
references: 16573127
references: Science. 1980 May 2;208(4443):500-2
references: 17744562
references: Environ Microbiol. 2003 Apr;5(4):287-95
references: 12662176
references: Trends Microbiol. 1999 Mar;7(3):111-5
references: 10203839
references: Appl Environ Microbiol. 2007 Apr;73(7):2135-43
references: 17277198
references: Appl Environ Microbiol. 2007 Jan;73(2):630-6
references: 17114321
references: Anal Biochem. 2004 Aug 1;331(1):106-14
references: 15246002
references: Appl Environ Microbiol. 2008 Dec;74(23):7163-73
references: 18849455
references: Mod Pathol. 2006 Sep;19(9):1181-91
references: 16778828
references: J Bacteriol. 1977 Jan;129(1):276-81
references: 401494
references: Annu Rev Microbiol. 1978;32:637-72
references: 360977
references: Microbiology (Reading). 1997 Apr;143 ( Pt 4):1181-1189
references: 9141681
references: J Bacteriol. 1992 Mar;174(5):1505-14
references: 1537795
references: Adv Microb Physiol. 2008;53:1-72
references: 17707143
references: Microbiol Res. 2008;163(4):456-65
references: 16971100
references: Appl Environ Microbiol. 2002 Sep;68(9):4613-22
references: 12200320
references: J Nanosci Nanotechnol. 2005 Nov;5(11):1768-84
references: 16433410
references: Appl Environ Microbiol. 1999 Nov;65(11):4734-40
references: 10543779
references: J Hazard Mater. 2009 Jun 15;165(1-3):71-7
references: 18977594
references: Langmuir. 2005 Jun 21;21(13):6002-5
references: 15952853
references: J Nanosci Nanotechnol. 2004 Jul;4(6):569-74
references: 15518388
references: Microbiology (Reading). 2002 Jun;148(Pt 6):1699-1708
references: 12055290
references: Appl Environ Microbiol. 2005 Sep;71(9):5607-9
references: 16151159
references: Protoplasma. 2003 May;221(1-2):153-61
references: 12768353
references: FEMS Microbiol Rev. 2009 Jul;33(4):820-32
references: 19368559