title: Affinity purification and characterization of a biodegradable plastic-degrading enzyme from a yeast isolated from the larval midgut of a stag beetle, Aegus laevicollis.
abstract: Two yeast strains, which have the ability to degrade biodegradable plastic films, were isolated from the larval midgut of a stag beetle, Aegus laevicollis. Both of them are most closely related to Cryptococcus magnus and could degrade biodegradable plastic (BP) films made of poly(butylene succinate) (PBS) and poly(butylene succinate-co-adipate) (PBSA) effectively. A BP-degrading enzyme was purified from the culture broth of one of the isolated strains employing a newly developed affinity purification method based on the binding action of the enzyme to the substrate (emulsified PBSA) and its subsequent degradative action toward the substrate. Partial amino acid sequences of this enzyme suggested that it belongs to the cutinase family, and thus, the enzyme was named CmCut1. It has a molecular mass of 21 kDa and a degradative activity for emulsified PBSA which was significantly enhanced by the simultaneous presence of Ca(2+) or Mg(2+) at a concentration of about 2.5 mM. Its optimal pH was 7.5, and the optimal temperature was 40 °C. It showed a broad substrate specificity for p-nitrophenyl (pNP)-fatty acid esters ranging from pNP-acetate (C2) to pNP-stearate (C18) and films of PBSA, PBS, poly(ε-caprolactone), and poly(lactic acid).
authors.affiliation: National Institute for Agro-Environmental Sciences (NIAES), 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Suzuki
authors.forename: Hironori
authors.initials: H
authors.lastname: Sakamoto
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Shinozaki
authors.forename: Jun
authors.initials: J
authors.lastname: Tabata
authors.forename: Takashi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Atsushi
authors.initials: A
authors.lastname: Mochizuki
authors.forename: Motoo
authors.initials: M
authors.lastname: Koitabashi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fujii
authors.forename: Seiya
authors.initials: S
authors.lastname: Tsushima
authors.forename: Hiroko K
authors.initials: HK
authors.lastname: Kitamoto
mesh_terms: D000272:Adipates / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D063566:Biodegradable Plastics / Q000378:metabolism*; D002072:Butylene Glycols / Q000378:metabolism; D002846:Chromatography, Affinity; D001517:Coleoptera / Q000254:growth & development / Q000382:microbiology*; D004795:Enzyme Stability; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D041981:Gastrointestinal Tract / Q000382:microbiology; D007814:Larva / Q000382:microbiology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011108:Polymers / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity; D013386:Succinates / Q000378:metabolism; D015003:Yeasts / Q000737:chemistry / Q000201:enzymology* / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D000272:Adipates; D063566:Biodegradable Plastics; D002072:Butylene Glycols; D005656:Fungal Proteins; D011108:Polymers; D013386:Succinates; C089797:bionole; C475864:poly(butylene succinate-co-butylene adipate)