• 한국염색가공학회지
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• 제18권4호
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• pp.20-27
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• 2006

Lyocell is a not only environmentally-friendly but also very advantageous fiber. When Lyocell is soaked in water, its wet tenacity does not decrease and elongation and moisture regain of it are better than cotton. However, one drawback of lyocell is its fibrillation. The fibrills of lyocell were generated during wet process such as scouring and dyeing deteriorates the dyeing color depth and the appearance of fabric. The purpose of this study was to decrease the fibrillation tendency of lyocell fabric using crosslinking agent, epichlorohydrine(ECH). The effects of NaOH scouring and ECH crosslinking were observed. The different types of ECH addition methods to lyocell and the various concentrations of ECH in crosslinking reaction onto dyeing characteristic and fibriallation were investigated. Weight loss and whiteness index of crosslinked lyocell by ECH were examined. K/S values of ECH treated lyocell fabrics dyed with reactive dye were measured and SEM images of untreated and treated lyocells were observed extensively to define the fibrillation tendency. The results were as follows ; 1) ECH treatment showed the effect of weight loss and scouring because ECH crosslinking reaction was conducted in alkaline condition. 2) The increase in ECH concentration from 5 to 30% does not affected K/S value changes. 3) ECH crosslinking can effectively prevent the fibrillation tendency of lyocell.

• Journal of Microbiology and Biotechnology
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• 제18권3호
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• pp.410-416
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• 2008

The gene SfXyn10, which encodes a protease-resistant xylanase, was isolated using colony PCR screening from a genomic library of a feather-degrading bacterial strain Streptomyces fradiae var. k11. The full-length gene consists of 1,437bp and encodes 479 amino acids, which includes 41 residues of a putative signal peptide at its N terminus. The amino acid sequence shares the highest similarity (80%) to the endo-1,4-${\beta}$-xylanase from Streptomyces coelicolor A3, which belongs to the glycoside hydrolase family 10. The gene fragment encoding the mature xylanase was expressed in Escherichia coli BL21 (DE3). The recombinant protein was purified to homogeneity by acetone precipitation and anion-exchange chromatography, and subsequently characterized. The optimal pH and temperature for the purified recombinant enzyme were 7.8 and $60^{\circ}C$, respectively. The enzyme showed stability over a pH range of 4.0-10.0. The kinetic values on oat spelt xylan and birchwood xylan substrates were also determined. The enzyme activity was enhanced by $Fe^{2+}$ and strongly inhibited by $Hg^{2+}$ and SDS. The enzyme also showed resistance to neutral and alkaline proteases. Therefore, these characteristics suggest that SfXyn10 could be an important candidate for protease-resistant mechanistic research and has potential applications in the food industry, cotton scouring, and improving animal nutrition.

• Journal of Microbiology and Biotechnology
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• 제21권8호
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• pp.861-868
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• 2011

A xylanase gene, xyn7c, was cloned from Paenibacillus sp. 12-11, an alkalophilic strain isolated from the alkaline wastewater sludge of a paper mill, and expressed in Escherichia coli. The full-length gene consists of 1,296 bp and encodes a mature protein of 400 residues (excluding the putative signal peptide) that belongs to the glycoside hydrolase family 10. The optimal pH of the purified recombinant XYN7C was found to be 8.0, and the enzyme had good pH adaptability at 6.5-8.5 and stability over a broad pH range of 5.0-11.0. XYN7C exhibited maximum activity at $55^{\circ}C$ and was thermostable at $50^{\circ}C$ and below. Using wheat arabinoxylan as the substrate, XYN7C had a high specific activity of 1,886 U/mg, and the apparent $K_m$ and $V_{max}$ values were 1.18 mg/ml and 1,961 ${\mu}mol$/mg/min, respectively. XYN7C also had substrate specificity towards various xylans, and was highly resistant to neutral proteases. The main hydrolysis products of xylans were xylose and xylobiose. These properties make XYN7C a promising candidate to be used in biobleaching, baking, and cotton scouring processes.