Bioactivity Evaluation Of Culture Dependent Microorganisms & Construction And Screening Of Soil Metagenome Library In Mangrove Environment

Twenty six samples including seeds, flowers, fruits, roots, barks and rhizosphere soil were collected from Shenzhen mangrove. Diversity of cultured bacterial, fungi and actinomyces on mangrove entironment were investigated. Water contents, salinities, pH, organic content, and P, K contents of the soil were analyzed and their effects on the colony forming units of bacteria, actinomycetes and fungi were analyzed.All strains with different colony-configuration were isolated from each mangrove samples and their bioactivity against tumor cell, Candida albicans and Staphylococcus aureus were detected respectively; which provide some referable data for exploiting the microbial resources in mangrove entironment.Soil DNA were extracted from two different mangrove samples, which are collected from Shenzhen and Zhanjiang. A metagenome library using pSK+ as vector including 5280 clones was constructed, whose DNA capacity is 15.5Mb.The average size of insert DNA is 3.2Kb.Bioactivity including anti-tumor cell; anti-Candida abbicans and anti-Staphylococcus aureus were screened on the library clones by function-driven screening stratege employing high through-put screening methods. Twelve clones showed anti- Candida abbicans bioactivity, which 10 clones were souresed from Shenzhen mangrove and 2 clones from Zhanjiang, with the active percentages to clones in the library were 0.298% and 0.104%, respectively. Among the 10 active clones of Shenzhen sample, 3 clones were obtained by single restriction enzyme lysis of Sau 3Aâ… and 7 clones were obtained by double restriction enzyme lysis of Bam Hâ… å’ŒEcoRâ… , as to the 2 active clones from Zhanjiang sample, each one of active clone was obtain for the two type of restriction enzyme lysis. The anti-Candida abbicans bioactive percentage of metagenome library that constructed from two different soli DNA is very different. One cytotoxic clone was obtained from Zhanjiang sample.DNA of two anti-Candida abbicans bioactive clones were sequenced and blasted in GeneBank.Among the most similar-sequences in respond to two clones, it is only 50.1% and 38.2% comparability , respectively.The DNA sequences of two clones are new and unassigned.