Abstract Details
(2020) Processes and Mechanisms of Se Transformations Mediated by Fungi
Rosenfeld C, Sabuda M, Santelli C, Yu Q & Fein J
https://doi.org/10.46427/gold2020.2224
The author has not provided any additional details.
07c: Room 2, Tuesday 23rd June 23:30 - 23:33
Carla Rosenfeld
View all 3 abstracts at Goldschmidt2020
View abstracts at 6 conferences in series
Mary Sabuda View abstracts at 3 conferences in series
Cara M. Santelli View all 4 abstracts at Goldschmidt2020
Qiang Yu View abstracts at 6 conferences in series
Jeremy Fein View abstracts at 3 conferences in series
Mary Sabuda View abstracts at 3 conferences in series
Cara M. Santelli View all 4 abstracts at Goldschmidt2020
Qiang Yu View abstracts at 6 conferences in series
Jeremy Fein View abstracts at 3 conferences in series
Listed below are questions that have been submitted by the community that the author will try and cover in their presentation. To submit a question, ensure you are signed in to the website. Authors or session conveners approve questions before they are displayed here.
Submitted by Elizabeth Herndon on Tuesday 23rd June 17:36
Is the abundance of sulfhydryl sites unique to these fungi, giving them the ability to bind Se well, or do these fungi increase expression of these binding sites in response to Se toxicity? Also, can other metals bind to and potentially outcompete Se for these sites - that is, are they non-selective?
We have only measured sulfhydryl sites on fungi in the absence of Se, so these fungi just seem to inherently have high sulfhydryls. Next steps would be to test Se adsorption before and after sulfhydryl blocking, and also the abundance of sulfhydryls on non-Se-reducing fungi. Also, yes - sulfhydryls play a big part in metal adsorption, so the presence of multiple metals could result in competition for the sites.
Is the abundance of sulfhydryl sites unique to these fungi, giving them the ability to bind Se well, or do these fungi increase expression of these binding sites in response to Se toxicity? Also, can other metals bind to and potentially outcompete Se for these sites - that is, are they non-selective?
We have only measured sulfhydryl sites on fungi in the absence of Se, so these fungi just seem to inherently have high sulfhydryls. Next steps would be to test Se adsorption before and after sulfhydryl blocking, and also the abundance of sulfhydryls on non-Se-reducing fungi. Also, yes - sulfhydryls play a big part in metal adsorption, so the presence of multiple metals could result in competition for the sites.
Submitted by Aaron Thompson on Tuesday 23rd June 22:49
What is known about the selenium volatilization mechanism in these fungal systems? Does it occur from the Se(0) that is taken into the cell? Is it possible that it is occuring outside the fungal cell and maybe a bacterial co-culture? Is it an enzyme-mediated process (I assume so)? Thanks and nice presentation. -AaronT
Not much is known about the volatilization mechanism. These aren't co-cultures, so it's not bacterial contribution in this case. I do agree, it is likely enzyme-mediated, though we aren't yet sure what enzyme it would be. We also aren't yet sure exactly what portion of the Se is being volatilized (i.e. Se(0) or other forms) but I think we could trace the process using isotopes which would greatly help clarify the mechanisms!
What is known about the selenium volatilization mechanism in these fungal systems? Does it occur from the Se(0) that is taken into the cell? Is it possible that it is occuring outside the fungal cell and maybe a bacterial co-culture? Is it an enzyme-mediated process (I assume so)? Thanks and nice presentation. -AaronT
Not much is known about the volatilization mechanism. These aren't co-cultures, so it's not bacterial contribution in this case. I do agree, it is likely enzyme-mediated, though we aren't yet sure what enzyme it would be. We also aren't yet sure exactly what portion of the Se is being volatilized (i.e. Se(0) or other forms) but I think we could trace the process using isotopes which would greatly help clarify the mechanisms!
Submitted by Pieter Bots on Tuesday 23rd June 23:42
Thank you for your presentation. Because of the nanoparticulate nature of Se(0) do you think that these could also form colloidal nanoparticles and provide a species that could relatively easily migrate through the environment?
yes, these are quite small nanoparticles, and likely may still have easy mobility in the environment. Hopefully we are going to be quantifying exactly how much Se(0) is biomass associated vs. truly colloidal (and not biomass affiliated) soon.
Thank you for your presentation. Because of the nanoparticulate nature of Se(0) do you think that these could also form colloidal nanoparticles and provide a species that could relatively easily migrate through the environment?
yes, these are quite small nanoparticles, and likely may still have easy mobility in the environment. Hopefully we are going to be quantifying exactly how much Se(0) is biomass associated vs. truly colloidal (and not biomass affiliated) soon.
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