How the giant panda digests lignin and lignin-related phenolic compounds from bamboo has puzzled scientists because of the lack of liguin-degrading genes in the bamboo-feeding animals genome.We constructed a 16S rRNA gene library of the microorganisms derived from the giant pandas feces to identify the possibility for existence of potential lignin-degrading bacteria.Phyiogenetic analysis showed that the phylotypes of the intestinal bacteria were affiliated with the phyla Proteobacteria (53%) and Firmicutes (47%).Two phylotypes assigned to Pseudomonas sp.showed high sequence identities to mangrove forest bacteria and Pseudomonas putida, indicating that lignin degradation microbes may exist in the gut of giant panda.To further verify that microbes in the gut help to degrade lignin, a metagenomic library of the intestinal bacteria was constructed and screened for clones that contained genes encoding laccase, a member of the lignin-degrading related enzymes.