Isolation, Purification And Evaluation Of Enzyme-producing Ability Of Thermophilic Xylanase Producing Bacteria From Hot Spring

“Jimo”Hot Springs is located in the town of Jimo City to the southwest. The average temperature of spring water is 66 ° C. The maximum temperature is up to 93 ° C. There is a wide range of chemical elements. There are a large amount of Na+ and Cl- and the total content of sodium chloride-water salinity up to 12 g/L. In addition, the geothermal water also contains Br, K, I, as well as many other elements such as radioactive elements Ra. The total solids in the water were 8092.60 mg / L, which is special geothermal water. Therefore, Jimo spring water will have fire-resistant characteristics and the high osmotic pressure antibiltiy.In this study, we first prepared semi cellulose by degradation method, and I add it to the medium for screening of strains producing xylanase. We found that that hemicellulose preparation efficiency is very high, about 13%, reaching the expected goal. We culture the Jimo hot spring water and found that there are many colonies growing in this medium, some of which have transparent circle. These results show that we are able to separate Xylanase Producing strains from the spring water. Further purification by dilution, three strains were selected, and the three strains have the big transparent circle colony. From the larger transparent circle strains, 3 strains of transparent circle maximum strains are further studied. Measurement values: plaque diameter D, transparent circle diameter of D, the enzyme producing ability of rough measurement of strain. The results showed, the plaque diameter of the 3 strains were 4.67, 6, 5.67, the average diameter of transparent circle was respectively 20.67, 25.67, 22. Transparent circle diameter to plaque of the 3 strains were respectively 4.42, 4.27, 3.88. These 3 strains were applied to the determine enzyme activity with spectrophotometric method. These results showed the enzyme activity were 334.11, 445.48, and 389.80 U/m L. We selected strains of A5, the highest enzyme activity, for further next research.This experiment separated and screened the thermophilic xylanase producing bacteria by assaying transparent zone on the selective medium from“ Jimo”Hot Spring. As a result we obtained 3 strains with high enzyme activity and could withstand high temperature. They grew well under 50℃ or even higher temperature. The thermophilic characteristic was beneficial to industrial production.