Prospects for Fungal Bioremediation of Acidic Radioactive Waste Sites: Characterization and Genome Sequence of Rhodotorula taiwanensis MD1149

Frontiers in Microbiology

Kenneth G. Frey¹  Theron Hamilton¹  Benjamin J. Stewart²  Stephanie A. Malfatti²  Mathew G. Lyman²  Bonnee Rubinfeld²  Lawrence Dugan²  Jatinder Singh³  Nina Gunde-Cimerman⁵  Cene Gostinčar⁵  Michael J. Daly⁶  Melanie Courtot⁷  Vera Y. Matrosova⁸  Polina Klimenkova⁸  Robert P. Volpe⁸  Elena K. Gaidamakova⁸  Rok Tkavc⁸  Olga E. Grichenko⁸  Carol E. Zhou⁹  Clifton L. Dalgard^1,10 

[1] 0Biological Defense Research Directorate, Naval Medical Research Center, Fredrick, MD, United States;Biosciences and Biotechnology Division, Physics and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, United States;Collaborative Health Initiative Research Program, Uniformed Services University of the Health Sciences, Bethesda, MD, United States;Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States;Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia;Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States;European Molecular Biology Laboratory, European Bioinformatics Institute, Cambridge, United Kingdom;Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States;Lawrence Livermore National Laboratory, Computing Applications and Research Department, Livermore, CA, United States;The American Genome Center, Bethesda, MD, United States;

关键词: bioremediation;    yeasts;    radiation resistance;    heavy metal resistance;    pH minimum;    temperature maximum;   

DOI  :  10.3389/fmicb.2017.02528

来源: DOAJ

【 摘 要 】

Highly concentrated radionuclide waste produced during the Cold War era is stored at US Department of Energy (DOE) production sites. This radioactive waste was often highly acidic and mixed with heavy metals, and has been leaking into the environment since the 1950s. Because of the danger and expense of cleanup of such radioactive sites by physicochemical processes, in situ bioremediation methods are being developed for cleanup of contaminated ground and groundwater. To date, the most developed microbial treatment proposed for high-level radioactive sites employs the radiation-resistant bacterium Deinococcus radiodurans. However, the use of Deinococcus spp. and other bacteria is limited by their sensitivity to low pH. We report the characterization of 27 diverse environmental yeasts for their resistance to ionizing radiation (chronic and acute), heavy metals, pH minima, temperature maxima and optima, and their ability to form biofilms. Remarkably, many yeasts are extremely resistant to ionizing radiation and heavy metals. They also excrete carboxylic acids and are exceptionally tolerant to low pH. A special focus is placed on Rhodotorula taiwanensis MD1149, which was the most resistant to acid and gamma radiation. MD1149 is capable of growing under 66 Gy/h at pH 2.3 and in the presence of high concentrations of mercury and chromium compounds, and forming biofilms under high-level chronic radiation and low pH. We present the whole genome sequence and annotation of R. taiwanensis strain MD1149, with a comparison to other Rhodotorula species. This survey elevates yeasts to the frontier of biology's most radiation-resistant representatives, presenting a strong rationale for a role of fungi in bioremediation of acidic radioactive waste sites.

【 授权许可】

Unknown