A novel marine microbial esterase PHE14 was cloned from the genome of Pseudomonas oryzihabit‐ans HUP022 isolated from the deep sea of the western Pacific Ocean. Esterase PHE14 exhibited very good tolerance to most or...A novel marine microbial esterase PHE14 was cloned from the genome of Pseudomonas oryzihabit‐ans HUP022 isolated from the deep sea of the western Pacific Ocean. Esterase PHE14 exhibited very good tolerance to most organic solvents, surfactants and metal ions tested, thus making it a good esterase candidate for organic synthesis that requires an organic solvent, surfactants or metal ions. Esterase PHE14 was utilized as a biocatalyst in the asymmetric synthesis of D‐methyl lactate by enzymatic kinetic resolution. D‐methyl lactate is a key chiral chemical. Contrary to some previous reports, the addition of an organic solvent and surfactants in the enzymatic reaction did not have a beneficial effect on the kinetic resolution catalyzed by esterase PHE14. Our study is the first report on the preparation of the enantiomerically enriched product D‐methyl lactate by enzymatic kinetic resolution. The desired enantiomerically enriched product D‐methyl lactate was obtained with a high enantiomeric excess of 99%and yield of 88.7%after process optimization. The deep sea mi‐crobial esterase PHE14 is a green biocatalyst with very good potential in asymmetric synthesis in industry and can replace the traditional organic synthesis that causes pollution to the environment.展开更多
This paper deduces a kinetic model for microbial degradation of pesticides in soils:where x is the concentration of pesticide at time t, so the initial concentration of the pesticide, me the initial number of pesticid...This paper deduces a kinetic model for microbial degradation of pesticides in soils:where x is the concentration of pesticide at time t, so the initial concentration of the pesticide, me the initial number of pesticide-degrading microorganisms, M the carrying capacity for the microorganisms, μ the specific growth rate of the microorganisms, and k the rate constant for the pesticide degradation.In periodic applications of pesticides, this model can be used to continuously describe every degradation curve. Whether a lag phase occurs or not, we can obtain the minimum residue of the pesticide (xe):xe=xdexp(-kMr)/[1-exp(-ker) ]where r is the regular time internals between applications, and xd the dosage of the pesticide.展开更多
The overall objective of the present study is to evaluate the impact of the heap fermentation of cocoa on microbial dynamics and physicochemical parameters of the soil. The methodology was to heap fermentation broad b...The overall objective of the present study is to evaluate the impact of the heap fermentation of cocoa on microbial dynamics and physicochemical parameters of the soil. The methodology was to heap fermentation broad beans 600 cocoa pods moved to a place after the soil was taken for microbiological and physicochemical analyzes considered the control sample. In addition, cocoa lixiviate and soil were subjected to analyze. Chemical analysis of cocoa lixiviate revealed the absence of heavy metals such as cadmium, chromium. It appears from the analysis of soil than clays represent on average 46.67%, 8.03% for fine silt, heavy silt 5.69%, 15.39% fine sands and heavy sands 20.02%. Microbiological analysis revealed the abundance of total coliform up to 4.6× 103 CFU/g soil. The variations of the abundance of yeasts are 0.01 × 103 CFU/g soil obtained on day 2 at 12 o＇clock to 3.5 × 103 CFU/g soil observed on day 3 to 18 pm （0-3 cm deep）. However, further study on the assessment of biodiversity after the fermentation would determine its species richness.展开更多
Entosis, a ceU-in-ceU process, has been implicated in the formation of aneuploidy associated with an aberrant cell division control. Microtubule plus-end-tracking protein TI P150 facilitates the loading of MCAK onto t...Entosis, a ceU-in-ceU process, has been implicated in the formation of aneuploidy associated with an aberrant cell division control. Microtubule plus-end-tracking protein TI P150 facilitates the loading of MCAK onto the microtubule plus ends and orchestrates micro- tubule plus-end dynamics during cell division. Here we show that TIP150 cooperates with MCAK to govern entosis via a regulatory cir- cuitry that involves Aurora A-mediated phosphorylation of MCAK. Our biochemical analyses show that MCAK forms an intra-molecular association, which is essential for TIP150 binding. Interestingly, Aurora A-mediated phosphorylation of MCAK modulates its intra-mo- lecular association, which perturbs the MCAK-TI P150 interaction in vitro and inhibits entosis in vivo. To probe if MCAK-TIP150 inter- action regulates microtubule plasticity to affect the mechanical properties of ceUs during entosis, we used an optical trap to measure the mechanical rigidity of live MCF7 ceils. We find that the MCAK cooperates with TIP150 to promote microtubule dynamics and modulate the mechanical rigidity of the cells during entosis. Our results show that a dynamic interaction of MCAK-TI P150 orchestrated by Aurora A-mediated phosphorylation governs entosis via regulating microtubule plus-end dynamics and cell rigidity. These data reveal a previously unknown mechanism of Aurora A regulation in the control of microtubule plasticity during ceU-in-ceU pro- cesses.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA11030404)Key Project from the Chinese Academy of Sciences (KGZD-EW-606)+1 种基金the National Natural Science Foundation of China (21302199)Guangzhou Science and Technology Plan Projects (201510010012)~~
文摘A novel marine microbial esterase PHE14 was cloned from the genome of Pseudomonas oryzihabit‐ans HUP022 isolated from the deep sea of the western Pacific Ocean. Esterase PHE14 exhibited very good tolerance to most organic solvents, surfactants and metal ions tested, thus making it a good esterase candidate for organic synthesis that requires an organic solvent, surfactants or metal ions. Esterase PHE14 was utilized as a biocatalyst in the asymmetric synthesis of D‐methyl lactate by enzymatic kinetic resolution. D‐methyl lactate is a key chiral chemical. Contrary to some previous reports, the addition of an organic solvent and surfactants in the enzymatic reaction did not have a beneficial effect on the kinetic resolution catalyzed by esterase PHE14. Our study is the first report on the preparation of the enantiomerically enriched product D‐methyl lactate by enzymatic kinetic resolution. The desired enantiomerically enriched product D‐methyl lactate was obtained with a high enantiomeric excess of 99%and yield of 88.7%after process optimization. The deep sea mi‐crobial esterase PHE14 is a green biocatalyst with very good potential in asymmetric synthesis in industry and can replace the traditional organic synthesis that causes pollution to the environment.
文摘This paper deduces a kinetic model for microbial degradation of pesticides in soils:where x is the concentration of pesticide at time t, so the initial concentration of the pesticide, me the initial number of pesticide-degrading microorganisms, M the carrying capacity for the microorganisms, μ the specific growth rate of the microorganisms, and k the rate constant for the pesticide degradation.In periodic applications of pesticides, this model can be used to continuously describe every degradation curve. Whether a lag phase occurs or not, we can obtain the minimum residue of the pesticide (xe):xe=xdexp(-kMr)/[1-exp(-ker) ]where r is the regular time internals between applications, and xd the dosage of the pesticide.
文摘The overall objective of the present study is to evaluate the impact of the heap fermentation of cocoa on microbial dynamics and physicochemical parameters of the soil. The methodology was to heap fermentation broad beans 600 cocoa pods moved to a place after the soil was taken for microbiological and physicochemical analyzes considered the control sample. In addition, cocoa lixiviate and soil were subjected to analyze. Chemical analysis of cocoa lixiviate revealed the absence of heavy metals such as cadmium, chromium. It appears from the analysis of soil than clays represent on average 46.67%, 8.03% for fine silt, heavy silt 5.69%, 15.39% fine sands and heavy sands 20.02%. Microbiological analysis revealed the abundance of total coliform up to 4.6× 103 CFU/g soil. The variations of the abundance of yeasts are 0.01 × 103 CFU/g soil obtained on day 2 at 12 o＇clock to 3.5 × 103 CFU/g soil observed on day 3 to 18 pm （0-3 cm deep）. However, further study on the assessment of biodiversity after the fermentation would determine its species richness.
文摘Entosis, a ceU-in-ceU process, has been implicated in the formation of aneuploidy associated with an aberrant cell division control. Microtubule plus-end-tracking protein TI P150 facilitates the loading of MCAK onto the microtubule plus ends and orchestrates micro- tubule plus-end dynamics during cell division. Here we show that TIP150 cooperates with MCAK to govern entosis via a regulatory cir- cuitry that involves Aurora A-mediated phosphorylation of MCAK. Our biochemical analyses show that MCAK forms an intra-molecular association, which is essential for TIP150 binding. Interestingly, Aurora A-mediated phosphorylation of MCAK modulates its intra-mo- lecular association, which perturbs the MCAK-TI P150 interaction in vitro and inhibits entosis in vivo. To probe if MCAK-TIP150 inter- action regulates microtubule plasticity to affect the mechanical properties of ceUs during entosis, we used an optical trap to measure the mechanical rigidity of live MCF7 ceils. We find that the MCAK cooperates with TIP150 to promote microtubule dynamics and modulate the mechanical rigidity of the cells during entosis. Our results show that a dynamic interaction of MCAK-TI P150 orchestrated by Aurora A-mediated phosphorylation governs entosis via regulating microtubule plus-end dynamics and cell rigidity. These data reveal a previously unknown mechanism of Aurora A regulation in the control of microtubule plasticity during ceU-in-ceU pro- cesses.
