Structure and function of a novel thermostable pullulanase / 生物工程学报
Chinese Journal of Biotechnology
;
(12): 119-128, 2014.
Article
in Chinese
| WPRIM
| ID: wpr-242406
ABSTRACT
Research on novel pullulanase has major significance on the domestic industrialization of pullulanase and the breakdown of foreign monopoly. A thermophilic bacteria LM 18-11 producing thermostable pullulanase was isolated from Lunma hot springs of Yunnan province. It was identified as Anoxybacillus sp. by 16S rDNA phylogenetic analysis. Full-length pullulanase gene was cloned from Anoxybacillus sp. LM18-11. The optimum temperature of the pullulanase was between 55 and 60 degrees C with a half-life as long as 48 h at 60 degrees C; and its optimum pH was between 5.6 and 6.4. V(max) and K(m) of the pullulanase was measured as 750 U/mg and 1.47 mg/mL, which is the highest specific activity reported so far. The pullulanase crystals structure showed a typical alpha-amylase family structure. The N-terminal has a special substrate binding domain. Activity and substrate binding were decreased when the domain was deleted, the V(max) and K(m) were 324 U/mg and 1.95 mg/mL, respectively. The pullulanase was highly heterologous expressed in Bacillus subtilis by P43 promoter. The extracellular enzyme activity was 42 U/mL, which increased more than 40 times compared to the initial strain. This pullulanase has good application prospects.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Phylogeny
/
Temperature
/
RNA, Ribosomal, 16S
/
China
/
Classification
/
Anoxybacillus
/
Genetics
/
Glycoside Hydrolases
/
Hydrogen-Ion Concentration
/
Metabolism
Country/Region as subject:
Asia
Language:
Chinese
Journal:
Chinese Journal of Biotechnology
Year:
2014
Type:
Article
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