BackgroundGenetic　resources　are　important　natural　assets.　Discovery　of　new　enzyme　gene　sequences　has　been　an　ongoing　effort　in　biotechnology　industry.　In　the　genomic　age,　genomes　of　microorganisms　from　various　environments　have　been　deciphered.　Increasingly,　it　has　become　more　and　more　difficult　to　find　novel　enzyme　genes.　In　this　work,　we　attempted　to　use　the　easily　accessible　banknotes　to　search　for　novel　microbial　gene　sequences.ResultsWe　used　high-throughput　genomic　sequencing　technology　to　comprehensively　characterize　the　diversity　of　microorganisms　on　the　US　dollars　and　Chinese　Renminbis　(RMBs).　In　addition　to　finding　a　vast　diversity　of　microbes,　we　found　a　significant　number　of　novel　gene　sequences,　including　an　unreported　superoxide　dismutase　(SOD)　gene,　whose　catalytic　activity　was　further　verified　by　experiments.ConclusionsWe　demonstrated　that　banknotes　could　be　a　good　and　convenient　genetic　resource　for　finding　economically　valuable　biologicals.