[Construction of large fragment metagenome library of natural mangrove soil]

Applying our optimized direct extraction method, the percentage of large fragment DNA in the total extracted mangrove soil DNA was significant increased. The large fragment metagenome library derived from natural mangrove soil over four seasons was successfully constructed by the optimized DNA extraction and electro elution purification method. All of the clones had recombinant Cosmids and each differed in their fragment profiles when Cosmid DNA was extracted from 12 randomly picked colonies and digested with BamHI. The average insert size for this library was larger than 35 kbp. This culturing-independent library at least encompassed 335 Mbp valuable genetic information of mangrove soil microbes. It allowed mining of valuable intertidal microbial resource to become a reality. It is a recommended method for those researchers who have still not circumvented the large insert environmental libraries or for those beginning research in this field, so as to avoid them attempting repetitive, fussy work.