title: Prevention of Bacterial Contamination of a Silica Matrix Containing Entrapped β-Galactosidase through the Action of Covalently Bound Lysozymes.
abstract: β-galactosidase was successfully encapsulated within an amino-functionalised silica matrix using a "fish-in-net" approach and molecular imprinting technique followed by covalent binding of lysozyme via a glutaraldehyde-based method. Transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy were used to characterise the silica matrix hosting the two enzymes. Both encapsulated β-galactosidase and bound lysozyme exhibited high enzymatic activities and outstanding operational stability in model reactions. Moreover, enzyme activities of the co-immobilised enzymes did not obviously change relative to enzymes immobilised separately. In antibacterial tests, bound lysozyme exhibited 95.5% and 89.6% growth inhibition ofStaphylococcus aureusATCC (American type culture collection) 653 andEscherichia coliATCC 1122, respectively. In milk treated with co-immobilised enzymes, favourable results were obtained regarding reduction of cell viability and high lactose hydrolysis rate. In addition, when both co-immobilised enzymes were employed to treat milk, high operational and storage stabilities were observed. The results demonstrate that the use of co-immobilised enzymes holds promise as an industrial strategy for producing low lactose milk to benefit people with lactose intolerance.
authors.affiliation: Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun 130012, China. liheng12@mails.jlu.edu.cn.|Informalization Center for Education and Management, Jilin Agricultural University, Changchun 130118, China. liheng12@mails.jlu.edu.cn.
authors.forename: Heng
authors.initials: H
authors.lastname: Li
authors.affiliation: Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun 130012, China. ls2012@jlu.edu.cn.
authors.forename: Shuai
authors.initials: S
authors.lastname: Li
authors.affiliation: Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun 130012, China. tianpu@jlu.edu.cn.
authors.forename: Pu
authors.initials: P
authors.lastname: Tian
authors.affiliation: College of Life Science, Jilin Agricultural University, Changchun 130118, China. wzf@jlau.edu.cn.
authors.forename: Zhuofu
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun 130012, China. lzq@jlu.edu.cn.
authors.forename: Zhengqiang
authors.initials: Z
authors.lastname: Li
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000494:pharmacology; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects; D006868:Hydrolysis / Q000187:drug effects; D007785:Lactose / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008892:Milk / Q000737:chemistry; D054802:Molecular Imprinting; D009113:Muramidase / Q000737:chemistry* / Q000494:pharmacology; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013211:Staphylococcus aureus / Q000187:drug effects; D014961:X-Ray Diffraction; D001616:beta-Galactosidase / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D004800:Enzymes, Immobilized; D012822:Silicon Dioxide; D009113:Muramidase; D001616:beta-Galactosidase; D007785:Lactose
keywords: covalent binding; encapsulation; lysozyme; β-galactosidase