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Torres-Bañaga R, Mares-Alejandre RE, Terán-Ramírez C, Estrada-González AL, Muñoz-Muñoz PLA, Meléndez-López SG, Rivero IA, Ramos-Ibarra MA. Functional Display of an Amoebic Chitinase in Escherichia coli Expressing the Catalytic Domain of EhCHT1 on the Bacterial Cell Surface. Appl Biochem Biotechnol 2020; 192:1255-1269. [PMID: 32715415 DOI: 10.1007/s12010-020-03389-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 07/16/2020] [Indexed: 11/30/2022]
Abstract
Poor solubility is the main drawback of the direct industrial exploitation of chitin, the second most abundant biopolymer after cellulose. Chemical methods are conventional to solubilize chitin from natural sources. Enzymatic hydrolysis of soluble chitinous substrates is a promising approach to obtain value-added by-products, such as N-acetylglucosamine units or low molecular weight chito-oligomers. Protein display on the bacterial membrane remains attractive to produce active enzymes anchored to a biological surface. The Lpp-OmpA system, a gene fusion of the Lpp signal sequence with the OmpA transmembrane region, represents the traditional system for targeting enzymes to the E. coli surface. EhCHT1, the amoebic chitinase, exhibits an efficient endochitinolytic activity and significant biochemical features, such as stability over a wide range of pH values. Using an extended Lpp-OmpA system as a protein carrier, we engineered E. coli to express the catalytic domain of EhCHT1 on the surface and assess the endochitinase activity as a trait. Engineered bacteria showed a consistent hydrolytic rate over a typical substrate, suggesting that the displayed enzyme has operational stability. This study supports the potential of biomembrane-associated biocatalysts as a reliable technology for the hydrolysis of soluble chitinous substrates.
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Affiliation(s)
- Ricardo Torres-Bañaga
- Grupo de Investigación en Biotecnología y Biociencias, Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Calzada Universidad 14418, 22390, Tijuana, BCN, Mexico
| | - Rosa E Mares-Alejandre
- Grupo de Investigación en Biotecnología y Biociencias, Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Calzada Universidad 14418, 22390, Tijuana, BCN, Mexico
| | - Celina Terán-Ramírez
- Grupo de Investigación en Biotecnología y Biociencias, Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Calzada Universidad 14418, 22390, Tijuana, BCN, Mexico
| | - Ana L Estrada-González
- Grupo de Investigación en Biotecnología y Biociencias, Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Calzada Universidad 14418, 22390, Tijuana, BCN, Mexico
| | - Patricia L A Muñoz-Muñoz
- Grupo de Investigación en Biotecnología y Biociencias, Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Calzada Universidad 14418, 22390, Tijuana, BCN, Mexico
| | - Samuel G Meléndez-López
- Grupo de Investigación en Biotecnología y Biociencias, Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Calzada Universidad 14418, 22390, Tijuana, BCN, Mexico
| | - Ignacio A Rivero
- Centro de Graduados e Investigación en Química, Instituto Tecnológico de Tijuana, Boulevard Industrial S/N, 22510, Tijuana, BCN, Mexico
| | - Marco A Ramos-Ibarra
- Grupo de Investigación en Biotecnología y Biociencias, Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Calzada Universidad 14418, 22390, Tijuana, BCN, Mexico.
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