User:Eewton/sandbox


 * 1) (Rickie) Bacteria do stuff with Hg
 * 2) Microbial activities play an important role in alleviating toxicity and mobility of pollutants such as Hg, however few studies have shown their roles outside of temperate regions  (1 sub 8,37).
 * 3) Microbes play an important role in Mercury cycling in the arctic. Specific microbes have the ability to reduce (convert) ionic Hg (HgII) to the volatile (easily moveable) elemental form (Hg0) (1,2). To study these unique microbes, scientists took samples from microbial mats in an Arctic coastal lagoon and from surface marine algae. Within the samples, most of the microbes were psychrophiles (reference or link to wiki page). Further results from their experiment indicate that microbes do this by using a process that is utilized by microbes throughout the world, however the gene encoding this process - merA - is unique to arctic microbes (1). 17 unique phylotypes (wiki link to explain) of this gene have been identified to encompass known MerA diversity; these phylotypes are closely related to others found in the Antarctic bacteria Polaromonas vacuolata and psychrophilic Alaskan bacteria Sphingopyxis alaskensis. Only approximately 5% of surface microbes were metabolically active in using their merA gene, and converted about 68% of bioavailable Hg to Hg(0). However, microbes deeper in depth have less access to light so merA-mediated activity increased to transform about 90% of bioavailable Hg.
 * 4) (1 - fig 6)
 * 5) (ref 3 fig 4)
 * 6) More on MerA:
 * 7) Requires Hg exposure concentraitons in the nmol/L range to activate (1 sub 64,52)
 * 8) For reference, normal range aka ‘pristine environments’ are pmol/L (1 sub 36,58)
 * 9) Hg is mostly present in negatively charged chlorocomplexes, which make it difficult for microbes to gain access to the Hg
 * 10) Snowpack chemistry affects microbial community structure in the Arctic. This means that how the snow and ice are positioned helps to determine which microbes live there - including the microbes containing the merA gene.
 * 11) Stuff to add if my section is sparse:
 * 12) Hg-sulfide complexes give passiv diffusion (1 sub 11)
 * 13) Hg complex transport (1 sub 26)
 * 14) Following conversion of all harmful Hg by these microbes, normal microbial growth to resume because the environment is no longer toxic (1).
 * 15) What bact are present and playing with Hg
 * 16) How they are doing it
 * 17) How they get it, what they do, and what happens to it
 * 18) This is variable on UV, input