A high-molecular-weight, cell-associated xylanase isolated from exponentially growing Thermoanaerobacterium sp. strain JW/SL-YS485

Journal Article · Wed Mar 01 04:00:00 EST 1995 · Applied and Environmental Microbiology

OSTI ID:625677

Shao, Weilan; DeBlois, S; Wiegel, J ^[1]

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1. Univ. of Georgia, Athens, GA (United States)

An unusual cell-associated {beta}-1,4-xylanase was purified to gel electrophoretic homogeneity from a cell extract of the bacterium thermoanaerobacterium sp. strain JW/SL-YS485 harvested at the late exponential growth phase. The molecular mass of the xylanase was 350 kDa as determined by gel filtration and 234 kDa as determined by native gradient gel electrophoresis. The enzyme contained 6% carbohydrates. Heterosubunits of 180 and 24 kDa were observed for the xylanase on sodium dodecyl sulfate-polyacrylamide gradient gel electrophoresis gels. The xylanase had a pl of 4.37 and a half-life of 1 h at 70{degrees}C. Using a 5-min assay, we observed the highest level of activity at pH 6.2 and 80{degrees}C. The KP{sub m} and k{sub cat} values when oat spelt xylan was used were 3 mg/ml and 26,680 U/{mu}mol, respectively. The Arrhenius energy was 41.8 kJ/mol. The purified enzyme differed in size, subunit structure, and location from other xylanases that have been described. The cell-associated enzyme activity appeared in the S-layer fraction.

• OSTI ID: 625677
• Journal Information: Applied and Environmental Microbiology, Journal Name: Applied and Environmental Microbiology Journal Issue: 3 Vol. 61; ISSN AEMIDF; ISSN 0099-2240
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
BACTERIA
CARBOHYDRATES
ENZYME ACTIVITY
FILTRATION
GELS
MOLECULAR STRUCTURE
PH VALUE
XYLANASE