Analysis of Bacterial Community within Termite Nest and the Potential of Biomass Degradation by its Consortia

• Main Authors: Hui-Ching Chuang, 莊蕙菁
• Other Authors: 柯淳涵
• Format: Others
• Language: en_US
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/11257424310044536049

碩士 === 國立臺灣大學 === 森林環境暨資源學研究所 === 99 === Because carbohydrate hydrolysis enzymes play an important role in bioethanol production, this study aims at the abilities of microorganism derived from termite nest to degrade biomass. 108 culturable bacteria for degradation test were selected, and through the enzyme activity assay they can be classified into 18 groups. After sequencing, all of these species are found to belong to one genus, Bacillus. The enzyme activity assay result shows that many enzymes, such as amylase, CMCase, licheninase, pectinase, xylanase, phytase, lipase and protease, are contained in the bacteria derived from the termite nest. To perform the pulp degradation test, we use three samples of different bacteria configuration to examine various enzyme activities: The sample of all kinds of culturable bacteria derived from termite nest, was coded as TG ALL, Bacillus subtilis and Bacillus amyloliquefaciens were nominated as TG 12 and TG 50. The enzymatic test include CMCase, Avicelase, Xylanase and β-Glucosidase, and the inducing conditions are in a 25% (w/v) Luria-Bertani borth (LB) medium and an M9 medium, respectively. In addition, acacia unbleached and bleached pulp is fed to judge the bleaching effect on the enzyme activity. The results show that enzyme activities are higher in the 25% LB medium than in the M9 medium. Also, TG 12 or TG 50 has higher activities than TG ALL. The ranking of the induced enzyme activity is as follows: xylanase, Avicelase, CMCase, β-Glucosidase. Through the intrinsic viscosity and released reducing sugar tests, we found that all the cultured samples can degrade acacia unbleached pulp DP off to 79.5 %, 81.1% and 79.6%; and degrade acacia bleached pulp DP of to LODP to 79.9 %, 83.5% and 87.7% of LODP in the 25% LB medium. On the other hand, they can degrade acacia unbleached pulp DP off to 79.5 %, 85.8% and 83.6%; and degrade acacia bleached pulp DP of to LODP to 85.0 %, 89.7% and 88.3% of LODP in the M9 medium.