Mode of action of Bacillus licheniformis pectin methylesterase on highly methylesterified and acetylated pectins. (22nd January 2015)

• Record Type: Journal Article
• Authors: Remoroza, Connie; Wagenknecht, Martin; Buchholt, Hans Christian; Moerschbacher, Bruno M.; Gruppen, Harry; Schols, Henk A.
• Is Part Of: Carbohydrate polymers. Volume 115(2015)
• Page Start: 540
• Page End: 550
• Publication Date: 2015-01-22
• Subjects: HILIC–MS/ELSD -- Fingerprinting -- Blockwise -- De-methylesterification -- Enzymology; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2014.09.016
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: A pectin methylesterase from Bacillus licheniformis is active on sugar beet pectin. An in-depth characterization of pectin methylesterase on sugar beet pectin by HILIC–MS. The bacterial PME ( Bli PME) is quite tolerant to acetyl groups. Bli PME de-methylesterifies lemon pectin and sugar beet pectin in a blockwise manner. Abstract: A gene encoding a putative pectinesterase from Bacillus licheniformis DSM13 was cloned and expressed in Escherichia coli. The resulting recombinant enzyme ( Bli PME) was purified and characterized as a pectin methylesterase. The enzyme showed maximum activity at pH 8.0 and 50 °C. Bli PME is able to release up to 100% of the methylesters from lime pectin (DM 34–76 → DM 0) and up to 73% of all methylesters from SBPs (DM 30–73 → DM 14). Bli PME efficiently de-methylesterifies lemon pectins and SBPs in a blockwise manner and is quite tolerant towards the acetyl groups present within the SBPs. Detailed analysis of the Bli PME-modified pectins using HILIC–MSn and the classical calcium reactivity measurement showed that the enzyme generates pectins with low methylesterification (lime and SBP) and high acetyl content (SBP) while creating blocks of nonmethylesterified galacturonic acid residues. The high activity of Bli PME towards highly methylesterified and acetylated pectins makes this novel esterase more efficient in removing methylesters from highly esterified beet pectin compared to other PMEs, e.g. Aspergillus niger PME.