1. Cloning of the thermostable cellulase gene from newly isolated Bacillus subtilis and its expression in Escherichia coli.
- Author
-
Li W, Zhang WW, Yang MM, and Chen YL
- Subjects
- Amino Acid Sequence, Bacillus subtilis genetics, Cellulase chemistry, Cloning, Molecular, Enzyme Stability, Escherichia coli genetics, Molecular Sequence Data, Sequence Alignment, Sequence Homology, Amino Acid, Temperature, Bacillus subtilis enzymology, Bacillus subtilis isolation & purification, Cellulase genetics, Cellulase metabolism, Escherichia coli metabolism, Gene Expression
- Abstract
A bacterial strain with high cellulase activity (0.26 U/ml culture medium) was isolated from hot spring, and classified and named as B. subtilis DR by morphological and 16SrDNA gene sequence analysis. A thermostable endocellulase, CelDR, was purified from the isolated strain. The optimum temperature of the enzyme reaction was 50 degrees C, and CelDR retained 70% of its maximum activity at 75 degrees C after incubation for 30 min. The putative gene celDR, consisting an open reading frame (ORF) of 1,524 nucleotides and encoding a protein of 508 amino acids with a molecular weight of 55 kDa, was purified from B. subtilis DR and cloned into pET-28a for expression. The cellulase production in E. coli BL21 (DE3) was enhanced to approximately three times that of the wild-type strain.
- Published
- 2008
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