title: Hg tolerance and biouptake of an isolated pigmentation yeast Rhodotorula mucilaginosa.
abstract: A pigmented yeast R1 with strong tolerance to Hg2+ was isolated. Phylogenetic identification based on the analysis of 26S rDNA and ITS revealed R1 is a Rhodotorula mucilaginosa species. R1 was able to grow in the presence of 80 mg/L Hg2+, but the lag phase was much prolonged compared to its growth in the absence of Hg2+. The maximum Hg2+ binding capacity of R1 was 69.9 mg/g, and dead cells could bind 15% more Hg2+ than living cells. Presence of organic substances drastically reduced bioavailability of Hg2+ and subsequently decreased Hg2+ removal ratio from aqueous solution, but this adverse effect could be remarkably alleviated by the simultaneous process of cell propagation and Hg2+ biouptake with actively growing R1. Furthermore, among the functional groups involved in Hg2+ binding, carboxyl group contributed the most, followed by amino & hydroxyl group and phosphate group. XPS analysis disclosed the mercury species bound on yeast cells was HgCl2 rather than HgO or Hg0.
authors.affiliation: College of Life Sciences and Oceanography, Shenzhen Key Laboratory of Marine Bioresources and Ecology, Shenzhen University, Shenzhen, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Liu
authors.affiliation: College of Life Sciences and Oceanography, Shenzhen Key Laboratory of Marine Bioresources and Ecology, Shenzhen University, Shenzhen, China.
authors.forename: Chaogang
authors.initials: C
authors.lastname: Wang
authors.affiliation: College of Life Sciences and Oceanography, Shenzhen Key Laboratory of Marine Bioresources and Ecology, Shenzhen University, Shenzhen, China.
authors.forename: Danxia
authors.initials: D
authors.lastname: Liu
authors.affiliation: Department of Chemical/Biochemical Engineering, Xiamen University, Xiamen, China.
authors.forename: Ning
authors.initials: N
authors.lastname: He
authors.affiliation: College of Life Sciences and Oceanography, Shenzhen Key Laboratory of Marine Bioresources and Ecology, Shenzhen University, Shenzhen, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Deng
mesh_terms: D001682:Biological Availability; D008628:Mercury / Q000378:metabolism / Q000633:toxicity*; D056951:Photoelectron Spectroscopy; D010858:Pigmentation; D012335:RNA, Ribosomal / Q000235:genetics; D012248:Rhodotorula / Q000235:genetics / Q000378:metabolism*
chemical_list: D012335:RNA, Ribosomal; C065096:RNA, ribosomal, 26S; D008628:Mercury