low molecular mass cutinase of Thielavia terrestris efficiently hydrolyzes poly(esters)

• Published in: Journal of industrial microbiology & biotechnology 2013-02, Vol.40 (2), p.217-226
• Main Authors: Yang, Shaoqing, Xu, Haibo, Yan, Qiaojuan, Liu, Yu, Zhou, Peng, Jiang, Zhengqiang
• Format: Article
• Language: English
• Subjects: acetates; acetone; Biochemistry; Biodegradable materials; Bioenergy/Biofuels/Biochemicals; Bioinformatics; Biological and medical sciences; Biomedical and Life Sciences; Biotechnology; Carbon; Carbon sources; Carboxylic Ester Hydrolases - chemistry; Carboxylic Ester Hydrolases - isolation & purification; Carboxylic Ester Hydrolases - metabolism; cutin; cutinase; dimethyl sulfoxide; Enzyme Stability; Enzymes; Esters; Ethanol; Fermentation; filtration; Fundamental and applied biological sciences. Psychology; Fungi; Genetic Engineering; hexanoic acid; Hydrogen-Ion Concentration; Hydrolysis; industrial applications; Inorganic Chemistry; isopropyl alcohol; Kinetics; Life Sciences; methanol; Microbiology; Molecular Weight; Plastics; polyacrylamide gel electrophoresis; Polyesters - chemistry; Polyesters - metabolism; polyethylene; Polyethylene terephthalate; Polymers; Proteins; solvents; Solvents - chemistry; Sordariales - enzymology; Studies; Substrate Specificity; succinic acid; Temperature; thermophilic fungi; Thielavia; Triticum aestivum; Wheat bran
• ISSN: 1367-5435; 1476-5535
• DOI: 10.1007/s10295-012-1222-x

A low molecular mass cutinase (designated TtcutA) from Thielavia terrestris was purified and biochemically characterized. The thermophilic fungus T. terrestris CAU709 secreted a highly active cutinase (90.4 U ml⁻¹) in fermentation broth containing wheat bran as the carbon source. The cutinase was purified 19-fold with a recovery yield of 4.8 %. The molecular mass of the purified TtcutA was determined as 25.3 and 22.8 kDa using SDS-PAGE and gel filtration, respectively. TtcutA displayed optimal activity at pH 4.0 and 50 °C. It was highly stable up to 65 °C and in the broad pH range 2.5–10.5. Extreme stability in high concentrations (80 %, v/v) of solvents such as methanol, ethanol, acetone, acetonitrile, isopropanol, and dimethyl sulfoxide was observed for the enzyme. The K ₘ values for this enzyme towards p-nitrophenyl (pNP) acetate, pNP butyrate, and pNP caproate were 7.7, 1.0, and 0.52 mM, respectively. TtcutA was able to efficiently degrade various ester polymers, including cutin, polyethylene terephthalate (PET), polycaprolactone (PCL), and poly(butylene succinate) (PBS) at hydrolytic rates of 3 μmol h⁻¹ mg⁻¹ protein, 1.1 mg h⁻¹ mg⁻¹ protein, 203.6 mg h⁻¹ mg⁻¹ protein, and 56.4 mg h⁻¹ mg⁻¹ protein, respectively. Because of these unique biochemical properties, TtcutA of T. terrestris may be useful in various industrial applications in the future.