Engineering the plastic degradation enzyme Ple629 from marine consortium to improve its thermal stability / 生物工程学报

Petrochemical-derived polyester plastics such as polyethylene terephthalate (PET) and polybutylene adipate terephthalate (PBAT) have been widely used. However, the difficulty to be degraded in nature (PET) or the long biodegradation cycle (PBAT) resulted in serious environmental pollution. In this connection, treating these plastic wastes properly becomes one of the challenges of environment protection. From the perspective of circular economy, biologically depolymerizing the waste of polyester plastics and reusing the depolymerized products is one of the most promising directions. Recent years have seen many reports on polyester plastics degrading organisms and enzymes. Highly efficient degrading enzymes, especially those with better thermal stability, will be conducive to their application. The mesophilic plastic-degrading enzyme Ple629 from the marine microbial metagenome is capable of degrading PET and PBAT at room temperature, but it cannot tolerate high temperature, which hampers its potential application. On the basis of the three-dimensional structure of Ple629 obtained from our previous study, we identified some sites which might be important for its thermal stability by structural comparison and mutation energy analysis. We carried out transformation design, and performed expression, purification and thermal stability determination of the mutants. The melting temperature (Tm) values of mutants V80C and D226C/S281C were increased by 5.2 ℃ and 6.9 ℃, respectively, and the activity of mutant D226C/S281C was also increased by 1.5 times compared with that of the wild-type enzyme. These results provide useful information for future engineering and application of Ple629 in polyester plastic degradation.

Auricular application press fit of dietary intervention in the treatment of perimenopausal syndrome / 中国基层医药

Objective To explore the auricular application pressure added dietary intervention of perimeno-pausal syndrome (PS)the influence of women's sex hormone levels.Methods Research subjects were randomly divided into two groups.The observation group was given auricular application pressure to add dietary intervention, control group was given dietary intervention alone.Before and after six months of follow -up,sex hormone levels in the blood were monitored.Results After the intervention,the estrogen level of the observation group was (272.93 ± 15.71)pmol/L,progesterone was (3.14 ±0.47)nmol/L,which of the control group was (186.32 ±12.80)pmol/L, (2.86 ±0.34)nmol/L;After the intervention,the follicular thorn hormone content of the two groups were decreased, which of the observation group was (12.88 ±1.50)U /L,which of the control group was (21.35 ±4.70)U /L;The perimenopausal symptoms were reduced,Kuppermun score in the observation group were (9.36 ±1.41 )points, (10.43 ±1.63)points,the difference between the two groups were statistically significant (t =40.15,4.52,3.82, 4.65,all P <0.01)for the control group.Conclusion Auricular application press fit dietary intervention for patients with perimenopausal syndrome sex hormone regulation of metabolic disorders has obvious effect,can significantly improve the patients'symptoms of the menopausal transition,it is worthy of further research on intervention measures.