Study On Strain Screening Of Haloduric And Alkaline Bacillus Sp. And Its Properties Of Cellulase

Cellulose as a very large number of renewable resources will be the important raw material in the food and energy areas. High cellulase which is adaptability, high activity and high stability is the key of degradating cellulose. Highly active cellulase strain selection is the important way to obtain high cellulase. The cellulase secreted from bacteria is mostly suitable for neutral and alkaline environment, which is strong ability to decomposite natural cellulose and can shorten the production time and has broad application prospects. In this paper, we selected and identified alkaline cellulase production Bacillua strain from the soil of Yellow River Delta, using advanced microbiological methods, and studied the strains'cultural conditions and properties. The main results and conclusions were as follows:1,23 strains Bacillus which produce high salt and alkali-resistant cellulase were isolated from the soil in Yellow River Delta, these strains were classified into four categories: Bacillus mojavensis, Pseudomonas aeruginosa, Bacillus subtilis and Bacillus cereus, using the methods identification of morphology, physical and chemical identification and molecular identification. The YRD-19 strain was Bacillus subtilis.2,The YRD-19 strain was the research object do the UV mutagens. We do the study about the cellulase activity stability of the 5 selected strains. The results showed that: The cellulase activity was still remain the original activity, the activity is induced 5.97 times the previous.3,the results showed that: the carbon source was 1.5% lactose, the nitrogen source was 1.5% peptone; NaCl:KH₂PO₄=5:1, the ratio of nutrients was 0.55%. The cultural conditions were as follows: the optimum original pH was 8.0; the optimum quantity of inoculation was 2%; the optimum seed activation time was 24 hours; the optimum fermentation time was 48 hours; the optimum cultural temperature was 37℃, the optimum liquid volume was 50 mL; the optimum rotation speed was 200r/min. Under these fermentation conditions, the cellulose was 229.6 U/g witch was 1.5 times of the previous 4,Studied the properties of strain YRD-19-35, the results showed that: the optimum temperature was 60℃; the optimum pH was pH8.0; When the salinity are reached, the cellulase can maintain 70% activity.