การศึกษาไซลาเนสจากจุลินทรีย์ทนด่างและอุณหภูมิสูงเพื่อนำไปประยุกต์ใช้ในอุตสาหกรรมเยื่อและกระดาษ

Name: จักรกฤษณ์ เตชะอภัยคุณ

Organization : มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี

Name: Chakrit Tachaapaikoon

keyword: thermostable alkaline xylanase

; xylan-binding xylanase

; adsorption-desorption on insoluble xylan (affinity chromatography)

; prebleaching of haft pulp

; Bacillus sp. C 9-1

Abstract: Thermostable alkaline xylanase producing thermophilic alkaliphilic xylanolytic microorganisms were isolated from a wastewater treatment plant and soil sample from SiarnCellulose Co. Ltd., in Thailand. All fifteen isolated strains produced xylanases but did not produce cellulase when grown in alkaline xylan medium. The optimum pHs of the xylanaseactivity of ten strains C 1-2, C 4-1, C 4-2, C 5-1, C 5-3,C 9-2, C 9-3, C 10-1, C 10-2, C 10-3 andC 11-1 were 6.0, while those of the other three strains C 6-1,C 9-1 and C 11-2 had optimum PHs of 8.0. Only one strain C 5-2 had two optimum pHs of 6.0 and 8.0. All strains showed thestability in the broad range of pH 7.0 to 11.0 for the xylanaseactivity and optimum temperature of 70 OC. Binding of xylanasesproduced from all strains to insoluble cellulose and insolublexylan wcre examined. Xylanases from the five strains C 9-2, C 9-3, C 10-1, C 10-3 and C 11-1were found to be capable of binding to both insoluble polysaccharides whereas those from the two strains, C 5-1 and C 11-2 were able to bind slightly. Xylanase from the rest of the strains, C 1-2, C 4-1, C 4-2, C 5-2, C 5-3, C 6-1, C 9-1 and C 10-2 were able to bind to only insoluble xylan. The hydrolysis of haft pulps in alkaline conditions by the xylanases from all strains was also investigated and showed that the hydrolysis rates of eucalyptus pulp were greater than those of sugarcane bagasse and pine pulps by xylanases from four strains C 6-1, C 9-1, C 10-1 and C 10-3. However, the hydrolysis rates of sugarcane bagasse pulp were greater than those of eucalyptus and pine pulps by xylanases from the rest of the strains. One of the strains, C 9-1 was found to produce high level of thermostable alkaline active cellulase-free xylanase with xylanbinding ability. Therefore, xylanase from the strain C 9-1 had a great potential for application in prebleaching of haft pulps. On the basis of physiological and biochemical studies, the strain C 9-1 was identified as belonging to the genus Bacillus. Bacillus sp. C 9-1 produced extracellular xylanolytic enzymes such as xylanase and arabinofuranosidase. The SDS-PAGEand active-PAGE showed that the culture supernatant contained three active bands with molecular masses of 23.5, 44.5 and 63.5kDa. One of the bands (23.5 ma) was found to be xylan-binding xylanase (XBX). It was purified to homogeneity by affinity chromatography. The optimum pH and temperature of the purified xylan-binding xylanase were 6.0 and, respectively. Its stability was in the range of pH 4.0 to 10.0 and temperature up to. Metal ions did not affect the xylanase activity and the purified XBX showed hydrolytic activity toward xylan only.

มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี

Address: กรุงเทพมหานคร (Bangkok)

Email: info.lib@mail.kmutt.ac.th

Name: รศ.ดร. กนก รัตนะกนกชัย

Role: อาจารย์ที่ปรึกษา

Created: 2542

Issued: 2006-01-11

Modified: 2006-05-30

วิทยานิพนธ์/Thesis

ISBN: 9746247603

CallNumber: BIT285

tha

DegreeName: วิทยาศาสตรมหาบัณฑิต

Level: ปริญญาโท

Descipline: เทคโนโลยีชีวภาพ

Grantor: มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี

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ลำดับที่.	ชื่อแฟ้มข้อมูล	ขนาดแฟ้มข้อมูล	จำนวนเข้าถึง	วัน-เวลาเข้าถึงล่าสุด
1	BIT285.pdf	11.19 MB	140	2022-05-24 23:52:58
2	BIT285ab.pdf	151.81 KB	44	2018-05-13 06:45:12
3	BIT285ab.txt	3.11 KB	54	2018-05-13 06:45:13

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