TY - JOUR
T1 - Selenium (IV,VI) reduction and tolerance by fungi in an oxic environment
AU - Rosenfeld, C. E.
AU - Kenyon, J. A.
AU - James, B. R.
AU - Santelli, C. M.
N1 - Publisher Copyright:
© 2017 John Wiley & Sons Ltd
PY - 2017/5
Y1 - 2017/5
N2 - Microbial processes are known to mediate selenium (Se) oxidation–reduction reactions, strongly influencing Se speciation, bioavailability, and transport throughout the environment. While these processes have commonly been studied in anaerobic bacteria, the role that aerobic fungi play in Se redox reactions could be important for Se-rich soil systems, dominated by microbial activity. We quantified fungal growth, aerobic Se(IV, VI) reduction, and Se immobilization and volatilization in the presence of six, metal-tolerant Ascomycete fungi. We found that the removal of dissolved Se was dependent on the fungal species, Se form (i.e., selenite or selenate), and Se concentration. All six species grew and removed dissolved Se(IV) or Se(VI) from solution, with five species reducing both oxyanions to Se(0) biominerals, and all six species removing at least 15%–20% of the supplied Se via volatilization. Growth rates of all fungi, however, decreased with increasing Se(IV,VI) concentrations. All fungi removed 85%–93% of the dissolved Se(IV) within 10 d in the presence of 0.01 mm Se(IV), although only about 20%–30% Se(VI) was removed when grown with 0.01 mm Se(VI). Fungi-produced biominerals were typically 50- to 300-nm-diameter amorphous or paracrystalline spherical Se(0) nanoparticles. Our results demonstrate that activity of common soil fungi can influence Se form and distribution, and these organisms may therefore play a role in detoxifying Se-polluted environments.
AB - Microbial processes are known to mediate selenium (Se) oxidation–reduction reactions, strongly influencing Se speciation, bioavailability, and transport throughout the environment. While these processes have commonly been studied in anaerobic bacteria, the role that aerobic fungi play in Se redox reactions could be important for Se-rich soil systems, dominated by microbial activity. We quantified fungal growth, aerobic Se(IV, VI) reduction, and Se immobilization and volatilization in the presence of six, metal-tolerant Ascomycete fungi. We found that the removal of dissolved Se was dependent on the fungal species, Se form (i.e., selenite or selenate), and Se concentration. All six species grew and removed dissolved Se(IV) or Se(VI) from solution, with five species reducing both oxyanions to Se(0) biominerals, and all six species removing at least 15%–20% of the supplied Se via volatilization. Growth rates of all fungi, however, decreased with increasing Se(IV,VI) concentrations. All fungi removed 85%–93% of the dissolved Se(IV) within 10 d in the presence of 0.01 mm Se(IV), although only about 20%–30% Se(VI) was removed when grown with 0.01 mm Se(VI). Fungi-produced biominerals were typically 50- to 300-nm-diameter amorphous or paracrystalline spherical Se(0) nanoparticles. Our results demonstrate that activity of common soil fungi can influence Se form and distribution, and these organisms may therefore play a role in detoxifying Se-polluted environments.
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U2 - 10.1111/gbi.12224
DO - 10.1111/gbi.12224
M3 - Article
C2 - 28044397
AN - SCOPUS:85007621180
SN - 1472-4677
VL - 15
SP - 441
EP - 452
JO - Geobiology
JF - Geobiology
IS - 3
ER -