Glucanase mutant with improved thermal stability and application thereof

The invention relates to a glucanase mutant with improved thermal stability and application thereof, the amino acid sequence of the mutant is that Ala at the 43rd site of wild type glucanase as shown in SEQ ID NO: 1 is mutated into Pro, and the amino acid sequence is as shown in SEQ ID NO: 2; thr at the 59th site is mutated into Ile, and the amino acid sequence is as shown in SEQ ID NO: 3; or Gly at the 165th site is mutated into Lys, and the amino acid sequence is as shown in SEQ ID NO: 4. When lichenin is taken as a substrate, compared with a wild type, the optimal pH value of the mutant has no obvious change, the specific activity of the mutant has no obvious change, the optimal temperature of the mutants A43P and T59I is increased by 5 DEG C compared with the wild type, and the half-life periods of the three mutants A43P, T59I and G165K at 60 DEG C are respectively prolonged by 34 minutes, 49 minutes and 24 minutes compared with the wild type (16 minutes). 一种热稳定性提高的葡聚糖酶突变体及其应用，所述突变体的氨基酸序列为SEQ ID NO:1所示的野生