Isolation And Purification Of Thermophiles And The Study Of Their Properties

Thermophiles are abundant in the nature environment; they are thermostable and thermophilic, and they also have excenlant degradation capability and high metabolic effiency, which leads to the wide use of their enzymes in some industries. However, the current research of thermophiles is inadequate. In order to better use the thermophiles resource and facilitate broader utilization of these resources in more industries, more thermophilies with high degradation capability are needed.A batch of thermophilic mircobes were isolated, purified and screened from various thermophilic composts, the growth characteristics, degradation capability, physiological and biochemical characteristics and preservation method were studied in this thesis, the result is listed below:1. 217 strains of thermophiles were isolated from various thermophilic composts using the LB medium and Nutrient Agar (YB), of which 91 (YB 54/LB 37)were from 60°C, 71 (YB 42/LB 29)were from 65°C, and 55 (YB 38/LB 17) were from°C.2. Understand the growth characteristics by completing the growth curve of the thermophiles. The results indicates that most of these thermophiles have relatively short lag phrase (less than 4 h), which is much shorter than most mesophiles. In addition, most of these thermophiles have longer exponential phrase, for example, many of these thermophiles have an exponential phase of more than 18 h. This fast growth rate is also reflected by many overgrowed culture medium when the thermophiles were isolated.3. The degradation capability was studied through the hydrolysis experiment of starch, fat, protein and cellulose. The result shows that most thermophiles have strong degradation capability to starch and fat, some thermophiles have strong degradation capability to cellulose.4. The physiological and biochemical characteristics study of these thermophiles shows that most thermophiles are rod-shaped. The thermophiles isolated from 60°C and 70°C are mainly gram-positive, while those isolated from 65°C are mainly gram-negative. Many of these thermophiles are spore-foming bacteria, and can produce oxidase and catalase, and have positive result during motility test. Majority of these thermophiles are aerobic, only a small portion are facultative, and the other few strains are anaerobic. 5. The study on thermophiles preservation method shows that liquid paraffin preservation, cryopreservation and freezedrying preservation method have better preservation effect under the environment of refrigerater and freezers.