title: Novel lipolytic enzymes identified from metagenomic library of deep-sea sediment.
abstract: Metagenomic library was constructed from a deep-sea sediment sample and screened for lipolytic activity. Open-reading frames of six positive clones showed only 33-58% amino acid identities to the known proteins. One of them was assigned to a new group while others were grouped into Families I and V or EstD Family. By employing a combination of approaches such as removing the signal sequence, coexpression of chaperone genes, and low temperature induction, we obtained five soluble recombinant proteins in Escherichia coli. The purified enzymes had optimum temperatures of 30-35°C and the cold-activity property. Among them, one enzyme showed lipase activity by preferentially hydrolyzing p-nitrophenyl palmitate and p-nitrophenyl stearate and high salt resistance with up to 4 M NaCl. Our research demonstrates the feasibility of developing novel lipolytic enzymes from marine environments by the combination of functional metagenomic approach and protein expression technology.
authors.affiliation: Marine Biotechnology Research Center, Korea Ocean Research & Development Institute, P.O. Box 29, Ansan 425-600, Republic of Korea.
authors.forename: Jeong Ho
authors.initials: JH
authors.lastname: Jeon
authors.forename: Jun Tae
authors.initials: JT
authors.lastname: Kim
authors.forename: Hyun Sook
authors.initials: HS
authors.lastname: Lee
authors.forename: Sang-Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Sung Gyun
authors.initials: SG
authors.lastname: Kang
authors.forename: Sang Ho
authors.initials: SH
authors.lastname: Choi
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Lee