Mikhail, there are a number of papers on the Internet dealing with the use of amino acids for leaching precious metals and base metals.  Glycine, being one of the simplest amino acids and therefore relatively cheap, was found to leach copper sulphides and native copper at ambient temperature, even chalcopyrite up to 70% extraction.  Elevating temperature to 50 deg C allows gold to be leached so it is possible to do a two stage leach with a liquor recovery step between for sequential metal recovery.  On the surface this looks like a great solution for copper-gold oxide orebodies but leach times are long and 0.1M glycine strength is needed, so a glycine recovery stage is needed making it more complicated.  It also needs an oxidant such as hydrogen peroxide for gold leaching. 

The use of glycine is covered by a patent by Curtin University in Australia which you should be aware of.  They have agents in different countries to licence the technology.  I think it would work well in a heap leach but tank leaching is a bit complicated but it does show promise. 

Mikhail, Curtin has passed the IP for Glycine leaching on to a company to develop. If you contact me username timekoehler on hot mail with some details I can put you in touch, regards Tim