Abstract
Two acetyl esterases (EC 3.1.1.6) were purified to gel electrophoretic homogeneity from Thermoanaerobacterium sp. strain JW/SL-YS485, an anaerobic, thermophilic endospore former which is able to utilize various substituted xylans for growth. Both enzymes released acetic acid from chemically acetylated larch xylan. Acetyl xylan esterases I and II had molecular masses of 195 and 106 kDa, respectively, with subunits of 32 kDa (esterase I) and 26 kDa (esterase II). The isoelectric points were 4.2 and 4.3, respectively. As determined by a 2-min assay with 4-methylumbelliferyl acetate as the substrate, the optimal activity of acetyl xylan esterases I and II occurred at pH 7.0 and 80 degrees C and at pH 7.5 and 84 degrees C, respectively. Km values of 0.45 and 0.52 mM 4-methylumbelliferyl acetate were observed for acetyl xylan esterases I and II, respectively. At pH 7.0, the temperatures for the 1-h half-lives for acetyl xylan esterases I and II were 75 degrees and slightly above 100 degrees C, respectively.
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- Bachmann S. L., McCarthy A. J. Purification and Cooperative Activity of Enzymes Constituting the Xylan-Degrading System of Thermomonospora fusca. Appl Environ Microbiol. 1991 Aug;57(8):2121–2130. doi: 10.1128/aem.57.8.2121-2130.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Christov L. P., Prior B. A. Esterases of xylan-degrading microorganisms: production, properties, and significance. Enzyme Microb Technol. 1993 Jun;15(6):460–475. doi: 10.1016/0141-0229(93)90078-g. [DOI] [PubMed] [Google Scholar]
- Freier Doris, Mothershed Cheryle P., Wiegel Juergen. Characterization of Clostridium thermocellum JW20. Appl Environ Microbiol. 1988 Jan;54(1):204–211. doi: 10.1128/aem.54.1.204-211.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hespell R. B., O'Bryan-Shah P. J. Esterase activities in Butyrivibrio fibrisolvens strains. Appl Environ Microbiol. 1988 Aug;54(8):1917–1922. doi: 10.1128/aem.54.8.1917-1922.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lee H., To R. J., Latta R. K., Biely P., Schneider H. Some Properties of Extracellular Acetylxylan Esterase Produced by the Yeast Rhodotorula mucilaginosa. Appl Environ Microbiol. 1987 Dec;53(12):2831–2834. doi: 10.1128/aem.53.12.2831-2834.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lee Y. E., Lowe S. E., Zeikus J. G. Regulation and Characterization of Xylanolytic Enzymes of Thermoanaerobacterium saccharolyticum B6A-RI. Appl Environ Microbiol. 1993 Mar;59(3):763–771. doi: 10.1128/aem.59.3.763-771.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lüthi E., Jasmat N. B., Bergquist P. L. Overproduction of an acetylxylan esterase from the extreme thermophile "Caldocellum saccharolyticum" in Escherichia coli. Appl Microbiol Biotechnol. 1990 Nov;34(2):214–219. doi: 10.1007/BF00166783. [DOI] [PubMed] [Google Scholar]
- McDermid K. P., Forsberg C. W., MacKenzie C. R. Purification and properties of an acetylxylan esterase from Fibrobacter succinogenes S85. Appl Environ Microbiol. 1990 Dec;56(12):3805–3810. doi: 10.1128/aem.56.12.3805-3810.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McDermid K. P., Mackenzie C. R., Forsberg C. W. Esterase Activities of Fibrobacter succinogenes subsp. succinogenes S85. Appl Environ Microbiol. 1990 Jan;56(1):127–132. doi: 10.1128/aem.56.1.127-132.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pohl T. Concentration of proteins and removal of solutes. Methods Enzymol. 1990;182:68–83. doi: 10.1016/0076-6879(90)82009-q. [DOI] [PubMed] [Google Scholar]
- Shao W., Wiegel J. Purification and characterization of a thermostable beta-xylosidase from Thermoanaerobacter ethanolicus. J Bacteriol. 1992 Sep;174(18):5848–5853. doi: 10.1128/jb.174.18.5848-5853.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]