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Metagenomic cloning is a powerful tool for the discovery of novel genes and biocatalysts from environmental microorganisms. Based on activity screening of a marine sediment microbial metagenomic library, a total of 19 fosmid clones showing lipolytic activity were identified. After subcloning, 15 different lipolytic genes were obtained; their encoded proteins showed 32–68% amino acid identity with proteins in the database. Multiple sequence alignment and phylogenetic tree analysis demonstrated that most of these predicted proteins are new members of known families of bacterial lipolytic enzymes. However, two proteins, FLS18C and FLS18D, could not be assigned to any known family, thus probably representing a novel family of the bacterial lipolytic enzyme. The activity assay results indicated that most of these lipolytic enzymes showed optimum temperature for hydrolysis at 40–50 °C with p-nitrophenol …