Expression, thermal stability modification and application in PHB degradation of polyhydroxyalkanoate depolymerase from Thermomonospora umbrina.
- Author:
Zhigang LI
1
;
Shiheng CHEN
1
;
Demin KONG
1
;
Sheng CHEN
1
;
Lei WANG
1
;
Jing WU
1
Author Information
- Publication Type:Journal Article
- Keywords: disulfide bond; polyhydroxyalkanoate; polyhydroxyalkanoate depolymerase; polyhydroxybutyrate; thermal stability modification
- MeSH: Thermomonospora; Actinomycetales; Escherichia coli/genetics*; Polyhydroxyalkanoates
- From: Chinese Journal of Biotechnology 2023;39(8):3351-3363
- CountryChina
- Language:Chinese
- Abstract: Polyhydroxyalkanoate depolymerase (PHAD) can be used for the degradation and recovery of polyhydroxyalkanoate (PHA). In order to develop a PHAD with good stability under high temperature, PHAD from Thermomonospora umbrina (TumPHAD) was heterelogously expressed in Escherichia coli BL21(DE3). At the same time, a mutant A190C/V240C with enhanced stability was obtained via rational design of disulfide bonds. Characterization of enzymatic properties showed that the mutant A190C/V240C had an optimum temperature of 60 ℃, which was 20 ℃ higher than that of the wild type. The half-life at 50 ℃ was 7 hours, at 50 ℃ which was 21 times longer than that of the wild type. The mutant A190C/V240C was used for the degradation of polyhydroxybutyrate (PHB), one of the typical PHA. At 50 ℃, the degradation rate of PHB being treated for 2 hours and 12 hours was 2.1 times and 3.8 times higher than that of the wild type, respectively. The TumPHAD mutant A190C/V240C obtained in this study shows tolerance to high temperature resistance, good thermal stability and strong PHB degradation ability, which may facilitate the degradation and recovery of PHB.
