Researchers at the Joint Genome Institute led the effort to successfully sequence the genome of the poplar (Populus) tree. They now have the candidate genes that will help domesticate poplar for biomass and reduce the cost from $50 to about $20 per ton, a boon to potential future production of biofuels. The U.S. Department of Energy Joint Genome Institute (DOE JGI), located in Walnut Creek, California, was created in 1997 to unite the expertise and resources in genome mapping, DNA sequencing, technology development, and information sciences. Biomass is biological material derived from living, or recently living organisms. It most often refers to plants or plant-based materials which are specifically called lignocellulosic biomass. As an energy source, biomass can either be used directly via combustion to produce heat, or indirectly after converting it to various forms of biofuel. Conversion of biomass to biofuel can be achieved by different methods which are broadly classified into: thermal, chemical, and biochemical methods.